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  • 1965-1969  (200,578)
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  • 1
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    New York, NY : Elsevier
    Keywords: Biochemistry ; Enzymes
    Notes: This is a series title, single volumes see link below.
    ISSN: 1557-7988
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  • 2
    Call number: QZ200Z:41
    Keywords: Oncology / Congresses
    Notes: Holdidngs of ZB: 1964-1988; Please search for single title in "Signatur" QZ200Z:41
    ISSN: 0069-4800
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  • 3
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    Stuttgart : Enke
    Call number: WB700:12(2)/1/Mag ; WB700:12(2)/2/Mag ; WB700:12(2)/3/Mag
    Description / Table of Contents: 1. Abth. Die allgemeinen acuten Infectionskrankheiten.--2. Abth. Die chronischen Infections- und Intoxications-Krankheiten, parasitäre Krankheiten, infectiöse Wundkrankheiten und chronische Ernährungs-Anomalieen.--3. Abth. Die Organkrankheiten
    Pages: 3 v.
    Edition: 2. vollständig neue Bearbeitung.
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    WB700:12(2)/1/Mag departmental collection or stack – please contact the library
    WB700:12(2)/2/Mag departmental collection or stack – please contact the library
    WB700:12(2)/3/Mag departmental collection or stack – please contact the library
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  • 4
    Call number: ZZ1980:9/Mag
    Keywords: Deutsches Krebsforschungszentrum Heidelberg ; Oncology / Database ; Bibliometrics ; DKFZ-publications
    Notes: Werke verschiedenner Autoren
    Pages: various pagings
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  • 5
    ISSN: 1432-1041
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Description / Table of Contents: Zusammenfassung 3H-g-Strophanthin wurde Patienten folgender drei Kategorien i.v. verabreicht: a) Kontrollpatienten b) Patienten mit eingeschränkter Leberfunktion (Cirrhose, Verschlußikterus) c) Patienten mit eingeschrankter Nierenfunktion (Pyelonephritis, Glomerulonephritis).. Bei den Kontrollpatienten nahm der Serumspiegel mit zwei Zeitkonstanten ab (t 1/2 20 min bzw. etwa 50 Std). 5–6 Std nach der Injektion betrug die Serumkonzentration nur noch 10% des Ausgangswertes. Nach 48 Std waxen etwa 61% der verabreichten Dosis mit dem Urin ausgeschieden worden. 3H-g-Strophanthin wurde in unveranderter Form eliminiert. Bei Leberkranken mit eingeschrankter Galleproduktion zeigte der zeitliche Verlauf des Serumspiegels und die Urinausscheidung dasselbe Verhalten wie bei den Kontrollpatienten. Von den nierenerkrankten Patienten dagegen worden in 48 Std nur 28% des verabreichten 3H-g-Strophanthin mit dem Urin ausgeschieden. Die Serumradioaktivität lag 6–48 Std nach der Injektion des Glykosids 2–3 mal so hoch wie bei den Kontrollen.
    Notes: Summary 3H-ouabain was administered intravenously to control patients, and to patients suffering from liver disease or renal failure. In the control patients the 3H-ouabain disappeared from the serum by two exponentials, with half-lives of about 20 min and 50 h, respectively. After 5–6 h only 8% of the initial serum concentration remained. During 48 h following drug administration about 61 % of the administered dose was excreted in the urine. 3H-ouabain was excreted as such and not metabolized. Liver disease accompanied by pathological impairment of bile production neither affected the disappearance from the serum nor the urinary excretion. During renal failure, however, only 28% of the administered 3H-ouabain was excreted with the urine during 48h. The serum level was 2–3 times higher than in the control patients.
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  • 6
    ISSN: 1432-1041
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In nine subjects representing a majority (75 percent) of the population tested, ten milligrams of Dexoxadrol combined with 600 mg of acetylsalicylic acid (ASA) was essentially equivalent to 20 or 30 mg of Dexoxadrol pooled sample when tested by ischemic arm method, both doses being significantly more potent than ASA alone one hour after dosage. Three hours after dosage, all doses of Dexoxadrol were still significantly above ASA alone or lactose placebo indicating a more prolonged action of this drug. The stimulating effect of lactose placebo is postulated to explain the temporary rise (1 h) noted by use of this substance. When all twelve subjects are considered, because of three negative reactors, only statistically significant differences between ten milligrams of Dexoxadrol plus 600 mg of ASA are distinguishable from ASA alone or placebo at the end of one hour. At all dosage levels some side effects similar to alcohol were noted, numbness, dizziness, drowsiness, etc., as described by (LASAGNA and PEARSON, 1965). The 30 and 20 mg dosage produced more prominent psychic effects, while the 10 mg dosage with ASA produced a minimum of such effects and was virtually as effective as the higher dosage in nine of twelve subjects.
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  • 7
    ISSN: 1432-1041
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Description / Table of Contents: Zusammenfassung An je 10 männlichen Versuchsper sonen wurde der Einfluß von 10 mg Diazepam (Valium®) und 50 mg Chlordiazepoxyd (Librium®) auf die Atmung untersucht. Dabei wurden Atemvolumen and alveolare CO2-Drucke bei Atmung von Zimmerluft und von 3 CO2-Luftgemischen (2.5%, 4% and 5.5% Vol CO2-Gehalt) gemessen und anhand von CO2-Atmungskurven ausgewertet. An weiteren je 10 Patienten mit fortgeschrittenem Lungenemphysem and Cor pulmonale wurde der Einfluß derselben Pharmaka anhand des zeitlichen Verhaltens der arteriellen Blutgase (pH, PCO2, PO2 and Standardbicarbonat) unter Berücksichtigung der pharmakologischen Schlafwirkung studiert. — Dabei fanden sich folgende Ergebnisse : 1. Weder bei Luftatmung noch bei CO2-Atmung ließen sich nach Diazepam und Chlordiazepoxyd auffällige Unterschiede in Atemfrequenz, Atemzugvolumen und Atemminutenvolumen bei herz- und lungengesunden Normalpersonen nachweisen. Die alveolaren CO2-Drucke blieben bei Luft- und CO2-Atmung im Mittel unbeeinflußt. — 2. Bei Patienten mit Lungenemphysem und manifester Hyperkapnie kam es nach Diazepam mit Einsetzen der Schlafwirkung zu einem signifikanten mittleren PCO2-Anstieg von 3 Torr, nach Chlordiazepoxyd im Mittel von 2 Torr mit entsprechender pH-Senkung von 13/1000 (Diazepam) und 1/100 (Chlordiazepoxyd). Nach Diazepam klang der hypoventilative Effekt nach 30 bis 45′, nach Chlordiazepoxyd nach 60 bis 75′ wieder ab. —3. Diese Veränderungen entsprechen der physiologisehen Schlafwirkung. Demzufolge 1st eine primäre (pharmakologische) Empfindlichkeitsänderung des Atemzentrums bei den angegebenen Dosierungen unwahrscheinlich. — 4. Die Auswirkungen einer zusätzlichen Relaxation der Atem muskulatur beim Emphysemkranken nach Gabe von Diazepam wird anhand der vorliegenden Literatur besprochen. —Vor der Gabe von Benzodiazepinen bei Patienten mit fortgesehrittenem Emphysem wird die blutgasanalytische Überprüfung der Atemfunktion angeraten und bei Fallen mit manifester Hyperkapnie eine zurückhaltende Dosierung empfohlen.
    Notes: Summary The influence of 10 mg Diazepam (Valium®) and 50 mg Chlordiazepoxyd (Librium®) on the respiration was studied in 10 healthy probands and 10 patients with emphysema of the lung. In the study of healthy persons the specific ventilation and the alveolar CO2 during the breathing of room-air and 3 different CO2-air-gasmixtures (2.5%, 4.0% and 5.5% Vol CO2-content) were measured and CO2-response-curves constructed. The influence of the same drugs was studied in 10 patients with advanced pulmonary emphysema and Cor pulmonale. In these patients the changes of the arterial blood-gases (pH, PCO2, PO2 and Standard bicarbonate) were determined over different periods of time. — Results: 1. After administration of the drugs in healthy persons no difference was seen in respiratory frequency, tidal volume and minute volume while breathing room-air and the different CO2-air-gas-mixtures. The mean of the alveolar PCO2 during room-air-and CO2-breathing were not altered. — 2. In patients with pulmonary emphysema and hypercapnia an increase of the mean PCO2 of 3 torr was seen shortly after the administration of Diazepam when the patients started to sleep. After Chlordiazepoxyd an increase of 2 torr in the mean PCO2 was seen. Corresponding a decrease in pH (13/1000 after Diazepam; 1/100 after Chlordiazepoxyd) was seen. This effect was abolished 30–45′ after the injection of Diazepam and 60–75′ after Chlordiazepoxyd. — 3. These changes equal the respiratory-patterns during sleep. It is the conclusion that there is no pharmacologically induced change in the sensitivity of the respiratory center in the used dosages of these drugs. — 4. The effects of a possible added relaxation of the respiratory muscles in patients with pulmonary emphysema after administration, of Diazepam is discussed. — In patients with pulmonary emphysema blood-gas-studies should be done prior to the administration of Benzodiazepines. They can be tried in patients with obvious hypercapnia cautiously, but especially in the case of Diazepam 10 mg/dosis should not be exceeded.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    ISSN: 1432-1041
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
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  • 9
    ISSN: 1432-1041
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A double-blind multicentre investigation has been set up in patients with angina pectoris to compare the activity of a beta-blocker (Ciba 39'089-Ba, Trasicor) with a placebo. Further, a follow-up study of the clinical effects after long-term treatment was carried out. — As criteria of evaluation the following were considered: number and severity of anginal attacks, consumption of nitroglycerin pills, physical condition, and performance. At the end of the trial the patients were asked to state which drug they preferred. The patients were checked for body weight, blood pressure, heart rate, ECG and side-effects. The data obtained on 62 patients were evaluated statistically. The analysis proved that Trasicor is more effective than the placebo in reducing the number of anginal attacks and the consumption of nitroglycerin pills, and is more effective in improving physical performance. No change was noticed in body weight but the heart rate and systolic blood pressure decreased with the drug. — Only mild side-effects were reported in a small number of patients. — A clear-cut reduction or total remission of anginal attacks and diminished nitroglycerin consumption were observed during the long-term study.
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  • 10
    ISSN: 1432-1041
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Twenty patients with neurocirculatory asthenia (NCA) have been investigated. They suffered from at least three out of seven defined symptoms and the severity of the symptoms prevented an ordinary daily activity. The patients were classified according to physiological variables and psychiatric (interview) criteria. They were treated with Aptin®, an adrenergic beta-blocking agent, and placebo in a double-blind cross-over design. From objective and subjective assessment of symptomatic improvement and drug preference, eight patients were classified as Aptin-responders and eleven as placebo responders. Physiological characteristics of hyperkinetic circulation due to increased activity of the sympathetic nerves was found in seven Aptin-responders but only in four placebo-responders. Six Aptin-responders were classified as anxiety states but only four placebo-responders. — The trial illustrates how therapy with a specific drug can reveal differences of probably etiological character in patients constituting a symptomatic entity. Adrenergic beta-blocking therapy in NCA seems to be of value predominately in patients with signs of hyperkinetic circulation and/or anxiety states.
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  • 11
    ISSN: 1432-1041
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Description / Table of Contents: Zusammenfassung Mittels einer relativ einfachen Bestimmungsmethodik läßt sich die Elimination von intravenös infundiertem Tromethamin messen. Dabei wurden in 72 Std bei acidotisch exsikkierten Kindern insgesamt nur 58.2 ± 12.8% unverändert ausgeschieden. Eine Kumulation bei wiederholter Gabe ist daher möglich. Weitere Untersuchungen sind erforderlich, um die Elimination von intravenös infundiertem Tromethamin unter klinischen Bedingungen zu bestimmen.
    Notes: Summary Renal excretion of tromethamine after intravenous infusion is measured with a relatively simple method. The amount excreted within 24 h in 15 acidotic, exsiccated children was only 29.78 ± 9.40% and after 72 h five children had excreted 58.20 ± 12.80 %. Repeated applications of tromethamine therefore may lead to accumulation. Further examinations are necessary to determine the renal and extrarenal elimination of intravenously infused tromethamine under clinical conditions.
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  • 12
    ISSN: 1432-1041
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Description / Table of Contents: Zusammenfassung Es wurde demonstriert, daß in allen untersuchten Testsystemen α2-Makroglobulin die Fibrinolysehemmwirkung der bisher verwendeten synthetischen Antifibrinolytika verstärkt, dem Sofortantiplasmin des Plasmas also eine kräftige, bisher nicht gewürdigte Mitwirkung bei der medikamentösen Fibrinolysehemmung zukommt. Ob α2-Makroglobulin die einzige Substanz ist, welche die medikamentöse Antifibrinolytikawirkung im Plasma mit beeinflußt, ist damit nicht abgeklärt. — Es erscheint nach unseren Analyseergebnissen möglich, daß dysproteinämische Zustände den zu erwartenden Wirkungsgrad der bisher therapeutisch einsetzbaren Fibrinolysehemmer verändern.
    Notes: Summary We were able to show that in all systems tested α2-macroglobulin increases the inhibitory action of all of the synthetic antifibrinolysins used. It has, in addition to the immediate antiplasmin of plasma, an intense effect that has not been recognized before on the drug-induced inhibition of fibrinolysin. Whether α2-macroglobulin is the only substance effecting the drug-induced antifibrinolytic in plasma remains to be explained. From our results it seems possible that dysproteinemic states change the intensity of effect which one expects of the fibrinolytic inhibitors used therapeutically to date.
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  • 13
    ISSN: 1432-1041
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Case histories of five patients are presented who developed severe postural hypotension after being treated with guanacline. The postural hypotension did not develop until treatment had been given for 3–4 months and has persisted following withdrawal of guanacline for 12–15 months. It is suggested that this drug causes irreversible depletion of noradrenaline stores in adrenergic nerve terminals in some patients.
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  • 14
    ISSN: 1432-1041
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The hydrolysis of benzoylcholine, 0.05 mM, butyrylcholine, 10 mM, and suxamethonium, 0.025 mM, by the plasma of 10 subjects who developed prolonged apnoea following suxamethonium administered during anaesthesia, were measured. Plasmas from all available relatives in four families were similarly studied. The plasma of 3 subjects contained only atypical cholinesterase and hydrolysed suxamethonium, relative to butyrylcholine, at a rate of only 1.6% of that seen with usual human cholinesterase. One subject appeared to have only atypical cholinesterase on the basis of dibucaine and fluoride numbers. Suxamethonium hydrolysis, however, was sixteen times greater than that for the 3 homozygous atypical subjects. Family studies and inhibition of butrylcholine hydrolysis by decamethonium established that this subject was heterozygous with about 20% of the total cholinesterase in the usual form. Two other subjects were also heterozygous for usual and either atypical or fluoride resistant genes. One of them hydrolysed suxamethonium at 25% of the usual rate, but the other had a normal rate of suxamethonium hydrolysis. Four subjects had no detectable anomaly of plasma cholinesterase, and hydrolysed suxamethonium normally. The apparent affinity of suxamethonium for usual and atypical cholinesterase was also determined and the significance of measurements of the hydrolysis of suxamethonium in relation to prolonged apnoea produced by the drug is discussed.
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  • 15
    ISSN: 1432-1041
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The nicotinic acid ester, pentaerythritol-tetranicotinate orally administered in a dose of 1 g produced a moderate but sustained level (≈ 1 μg/ml) of free nicotinic acid in plasma. The concentration of esterbound nicotinic acid increased in plasma too. The increased nicotinic acid concentration in plasma was accompanied by a significant and protracted increase of the blood-flow of the forearm and hand and a decrease of the FFA-content of plasma. A weak flush of the face and the upper part of the body occurred as long as the nicotinic acid concentration of plasma was increasing. Repeated doses of pentaerythritoltetranicotinate at short intervals (30 min) produced a larger increase of the nicotinic acid concentration in plasma but the pharmacological effects did not increase. This was in agreement with earlier results that already a plasma concentration of 0.3–0.4 μg/ml of nicotinic acid produced almost maximum pharmacological effects. Only the effect on the blood-flow of the forearm was significantly greater when the nicotinic acid dose and nicotinic acid level of plasma was further raised. It was calculated that 1 g pentaerythritoltetranicotinate produced a plasma level of nicotinic acid and pharmacological effects similar to those produced by a continous i.v. infusion of nicotinic acid in a dose of about 0.02 mg/kg/min for 6–7 h.
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  • 16
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    Archives of microbiology 64 (1969), S. 215-222 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The Clark oxygen electrode was used to measure the microbial oxidation of hydrocarbons using preparations of resting cell suspensions. A strain of Corynebacterium sp. (7E1C) which utilized n-octane as sole carbon and energy source was examined for its ability to oxidize a variety of hydrocarbon substrates. The oxidation by resting cells exhibited an optimal temperature of 30° and an optimal pH range of 7.0–7.6. 1-Octanol, octanal, and octanoic acid were oxidized at rates comparable to n-octane. With the exception of n-decane, n-alkanes from pentane through heptadecane were attacked with a progressive increase in specific activity up the homologous series to n-octane, followed by a decrease as the hydrocarbon chain became progressively longer. n-Alkenes and halogenated n-alkanes substituted in the one position were oxidized at appreciably lower rates than the corresponding n-alkanes. Iso-Alkanes, cyclo-alkanes and aromatic hydrocarbons were relatively unsusceptible to oxidative attack.
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  • 17
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    Archives of microbiology 64 (1969), S. 357-368 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Descriptive notes on morphological variations are given for these species of Phlyctochytrium in Iceland: P. biporosum, P. bullatum, P., equale, P. hallii, P. irregulare, P. indicum, and P. mucronatum. A Phlyctochytrium with urn-shaped sporangia possessing large discharge pores is described but is not named. Sporangial shape in this plant is nearly identical to that of Phlyctidium marinum, a Rhizophydium sp. reported by Sparrow and Koch, and two species of Chytriomyces. A second unnamed species resembling P. longicollum but having a more distinctive sporangium and a large apophysis, is reported from pine pollen.
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  • 18
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Es wird über eine Methode berichtet, an extrem dünnen Holzfolien die Abbauleistungen von Bodenpilzen zu messen. Aus einer Gesamtzahl von 280 geprüften Pilzarten wurden bei 27 mikroskopischen Pilzen mit hoher Aktivität Gewichtsabnahme und Reißfestigkeit von Ahornholz bestimmt. An Weizenstroh wurde mit einer Auswahl leistungsfähiger Pilze die Verminderung des Lignin- und Cellulosegehalts untersucht. Nach 120 Bebrütungstagen lag die Abnahme für Lignin zwischen 31 und 52%, für Cellulose zwischen 33 und 66%. Von den untersuchten Pilzen zeichneten sich Mammaria echinobotryoides, Hormiactis candida und Chaetomium piluliferum durch eine besonders starke Phenolproduktion aus. Die für alle geprüften Pilze mehr oder weniger typische Phenolproduktion stand in enger Beziehung zur Bildung von Huminstoffen, die bei der Rotte des Strohes auftraten.
    Notes: Summary The use of ultra-thin foils prepared from maple wood for measuring the wood-destroying capacity of soil fungi is described. Data are given on the reduction of dry-weight and tensile strength by the action of 27 highly active species from a total number of 280 microfungi. The decrease in lignin and cellulose content of wheat straw was studied with a selected number of fungi. The percentage reduction after an incubation period of 120 days was found to be between 31 and 52% for lignin, 33 and 66% for cellulose content respectively. A remarkable production of phenols was found in liquid cultures of Mammaria echinobotryoides, Hormiactis candida and Chaetomium piluliferum. The phenol production was more or less typical for all the examined fungi. There was a close relationship between the phenol metabolism and dark humic acid-like substances occurring during the decomposition of straw.
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  • 19
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Der Einfluß der Nährmedien, der Inkubationstemperatur und des Kulturalters auf die Strahlenempfindlichkeit verschiedener Stämme von Penicillium viridicatum und Aspergillus flavus wird beschrieben. Die Reaktivierbarkeit bestrahlter Conidien war auf optimalen Nährmedien erhöht. Bei A. flavus wurde die Reaktivierbarkeit bestrahlter Conidien durch optimale Bebrütungstemperatur begünstigt, während die bestrahlten P. viridicatum-Stämme höchste relative Wachstumsraten bei suboptimalen Temperaturen zeigten. Die Strahlenempfindlichkeit der Conidien nahm mit deren Alter zu. Bei aktiv wachsenden Pilzkulturen war die Strahlenempfindlichkeit gegenüber älteren Kulturen erhöht.
    Notes: Summary The influence of the growth media, the incubation temperature, and the age of the cultures on the radiation sensitivity of different strains of Penicillium viridicatum and Aspergillus flavus is described. The recovery of irradiated conidia was higher on optimal media. The recovery of irradiated conidia of A. flavus was favored by optimal incubation temperature, while those of P. viridicatum showed highest relative growth rates at suboptimal temperatures. The radiosensitivity of the conidia increased with age. Actively growing cultures of the moulds were more sensitive to radiation than older ones.
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  • 20
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    Archives of microbiology 64 (1969), S. 369-376 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary P. nigrifaciens produces a water-insoluble blue pigment on solid media which forms cuboidal crystals among the cells. The pigment was prepared by bulk harvest of isolated colonies incubated 5 days at 15°C. The cells were extracted with DMF and the extract benzene-precipitated and chromatographed over Sephadex LH-20. Analytical data were compiled leading to a provisional structure closely related to the pigments of P. indigofera and P. lemonnieri.
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  • 21
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Es wird das Vorkommen von Polysomensäulen bei Rhodopseudomonas palustris beschrieben. An Hand der Daten ergab sich, daß diese Polysomen aus zwei helixförmig angeordneten Ribosomensträngen aufgebaut sind, die eine linksdrehende Schraube bilden. Der Querschnitt der Schraube zeigt hexagonale Anordnung der Ribosomen. Der Steigungswinkel der Helices beträgt 200, der Gesamtdurchmesser der hexagonalen Polysomensäule beträgt 375 Å. Diese Polysomenart kommt lediglich in der begeißelten Polregion vor und ist dicht unter der Cytoplasmamembran lokalisiert. Die Polysomen stehen mit der Cytoplasmamembran in Kontakt. Ihre Längsachse läuft parallel zur Plasmamembran.
    Notes: Summary Helical arranged ribosomes were detected in the polar region of Rhodopseudomonas palustris cells. They are attached to the cytoplasmic membrane. The columnar polysomes are shaped of two helical strings of ribosomes, which are arranged around the axis of the screw. The vertical projection of the single ribosomes in one turn of the screw is a hexagon. The helices are left handed. The angle between the horizontal line and the ribosome chain in the helix is α=200. The diameter of the polyribosome column amounts to 375 Å.
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  • 22
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The carbohydrate composition and the specific activity of the trehalase of cyclic partially synchronised yeast populations have been investigated. Under glucose limitation and appropriate cultural conditions synchronous growth in a chemostat was achieved. The cells accumulated the reserve carbohydrates during the single cell phase between two buddings. The rapid degradation of part of these reserves began shortly before the swelling of the bud. The importance of the mobilisation of endogenous reserves for the development of the cell is discussed. The specific activity of the trehalase changed during the budding cycle. The result gives rise to the assumption that the synthesis of this enzyme is linked to the growth cycle.
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  • 23
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    Archives of microbiology 64 (1969), S. 387-395 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Measurements of nuclear positions in apical cells of homokaryotic mycelia and dikaryotic mycelium of Schizophyllum commune showed that nuclei occupied a near central position in most cases. Forward nuclear movements observed in living hyphal apices occurred at rates within the range of hyphal growth and could account for the maintenance of centrally located nuclei. Opposed nuclear movements followed mitosis and greatly exceeded the rate of hyphal growth. Septum disruption and rapid nuclear movements characterized an A xBmut homokaryon. Neither cytoplasmic streaming nor actively participating granules or filaments could account for any of these nuclear movements.
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  • 24
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ultrastructural study of Chlamydobotrys stellata shows that whilst the basic structure is volvocalean there are certain abnormalities for a green cell. The thylakoids are predominantly separated from each other in all but the central region of the cell, where small grana are present, under the growth conditions used in these experiments. Approximately three quarters of the thylakoids are separated from each other. Reticulate areas of disorganization are also present in the central region of the chloroplast. The absence of a demonstrable Hill reaction in C. stellata may be the result of restricted grana formation.
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  • 25
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung 1. Alle hydrogenase-positiven Chlorobium-Stämme (12 von insgesamt 17 untersuchten Stämmen) können Cystein bis zu einem gewissen Grade als S-Quelle für das Wachstum mit H2 verwerten. Eine assimilatorische Sulfatreduktion its nicht vorhanden; Methionin, Cystin, Cysteinsäure, Thioglycolat, Thioacetamid und Sulfit können in den geprüften Konzentrationen nicht als S-Quellen genutzt werden. 2. 35S-Cystein wird während des Wachstums mit H2 von den Zellen aufgenommen und 35S-markiertes Methionin gefunden. Beide Aminosäuren wurden im Zellprotein nachgewiesen. Das begrenzte Wachstum mit H2 wird darauf zurückgeführt, daß nicht alle S-Verbindungen der Zellen aus Cystein gebildet werden können. Die Unfähigkeit der Organismen, das normalerweise als S-Quelle genutzte Sulfid aus Cystein abzuspalten, wurde durch Versuche zur CO2-Fixierung mit Cystein nachgewiesen. 3. Bei gleichzeitiger Anwesenheit von Sulfid oder Thiosulfat und H2 werden beide H-Donatoren nebeneinander zur CO2-Fixierung genutzt. In statischer Kultur werden ca. 50% des fixieten CO2 durch H2 als H-Donator reduziert; in kontinuierlicher Kultur konnte der Anteil des mit H2 fixierten CO2 auf etwa 90% der Gesamtfixierung gesteigert werden. 4. Im Bereich niedriger Lichtintensitäten sind die CO2-Fixierungsraten mit H2 oder Thiosulfat gleich. Bei der CO2-Fixierung mit H2 tritt Lichtsättigung etwa bei 100–150 Lux ein, während die CO2-Fixierung mit Thiosulfat erst bei 700 Lux Lichtsättigung erreicht. Dieses Verhalten führt bei höheren Lichtintensitäten zu einer geringeren CO2-Fixierungsrate mit H2 im Vergleich zur Fixierungsrate mit Thiosulfat.
    Notes: Summary 1. All hydrogenase-positive Chlorobium-strains (12 out of 17 strains tested) can grow to some extent with cysteine as a sulfur source, when molecular hydrogen is electron donor. An assimilatory sulfate reduction does not exist. Methionine, cystine, cysteic acid, thioglycolate, thioacetamide, and sulfite in the concentrations tested can not be utilized as a source of cell sulfur. 2. 35S-cysteine is taken up by the cells during growth with hydrogen, and the 35S-label is found in methionine; both these labeled amino acids were shown to occur in the cell protein. The limited growth observed with hydrogen and cysteine may be due to the possibility that not all sulfur compounds of the Chlorobium cells can be built up from cysteine. Free sulfide, normally used as sulfur source, is not formed from cysteine as was shown by CO2-fixation experiments with cysteine. 3. If sulfide or thiosulfate is present in addition to hydrogen, both hydrogen donors are used simultaneously for CO2-fixation. In batch culture about 50% of the CO2 assimilated is reduced with hydrogen; in continous culture the portion of CO2 reduced by hydrogen could be increased to about 90% of total fixation. 4. At low light intensity the rates of CO2-fixation in the presence of hydrogen or thiosulfate are equal. Light saturation of CO2-fixation with hydrogen is reached at about 100–150 lux whereas CO2-fixation with thiosulfate becomes saturated at about 700 lux. At high light intensities this feature leads to a lower CO2-fixation rate with hydrogen.
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  • 26
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Arbeit beschreibt Aufbau und Eigenschaften einer Elektrode zur kontinuierlichen Messung des Sauerstoffpartialdruckes in Fermenterkulturen. Die nach dem polarographischen Prinzip arbeitende Elektrode leitet sich von der Clarkschen Meßanordnung ab. Ihr wesentliches Merkmal ist die Auftrennung in zwei selbständige Bauelemente, einen Membran-tragenden Glasmantel und den Elektroden-tragenden Meßgeber. Der Elektrodenmantel wird gemeinsam mit dem Fermentergefäß autoklaviert, der thermolabile Meßfühler dagegen erst nachträglich eingesetzt. Die Eichung der Elektrode kann vor dem Autoklavieren in einem Spezialgefäß oder danach im Fermentergefäß vorgenommen werden. Der sterilisierbare, in die Kulturlösung hineinragende Elektrodenmantel wird von der Lösung durch eine O2-permeable, 250μ starke Siliconglasgewebemembran abgeschlossen. Zwischen Siliconschicht und der blanken Platinoberfläche der Kathode befindet sich eine weitere, stabilisierende Membran von 12 μ Stärke (Cellophanfolie). Die Empfindlichkeit der Elektrode beträgt 10−9 A/mm Hg pO2 bei 37°C, die Einstellzeit auf 95% des Endwertes 50 sec bei 37°C. Die Abhängigkeit der Messungen von der Turbulenz des Mediums ist zwischen 400 und 1200 UpM Rührergeschwindigkeit zu vernachlässigen. Wiederholtes Autoklavieren der Siliconmembran hat keinen Einfluß auf die Einstellzeiten.
    Notes: Summary The paper describes the construction and properties of an electrode for continuous measurement of oxygen tension in fermenter cultures. The equipment is a modified Clark electrode with a cathode of 99,99% pure Pt and a silver anode. It works polarographically. Its most outstanding feature is the subdivision into two separate construction elements: an outer glass-envelope containing a membrane, and a membrane-carrying electrode. The glass-envelope is autoclavable together with the fermenter vessel, whereas the thermolabile electrode must be inserted into the sterilized glass-envelope. The electrode can be calibrated either in a special vessel before autoclaving the glass envelope, or after sterilization in the air-saturated sterile culture medium, before inoculation. The steam resistent glass-envelope, which is immersed in the culture medium, is covered on the lower part with a silicone membrane of 250 μ thickness which is stabilized by glass fibers. The silicone membrane is separated from the polished Pt cathode by a second stabilizing membrane (cellophane) of 12 μ thickness, which is part of the electrode. The sensitivity of the electrode is 10−9 A/mm Hg pO2 at 37° C. When the oxygen tension is changed from 0 to 100%, the electrode follows this change up to 95% within 50 sec at 37° C. The reading is nearly independent of the agitation of the medium between 400 and 1,200 rpm of the impeller turbine in the culture vessel. Repeated steam-sterilization has no influence on the response time of the electrode.
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  • 27
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Pyruvat kann durch belichtete Zellen von R. rubrum assimiliert und zur Synthese verschiedener Zellbestandteile verwendet werden. Ist das Angebot an Substrat und Lichtenergie groß genug, so wird ein Teil der Brenztraubensäure in Speicherstoffe eingebaut. Suspension der Zellen in Phosphat-puffer und Inkubation unter Wasserstoff stimuliert die Bildung des Speicherstoffes Poly-β-Hydroxybuttersäure. Die Synthese eines ebenfalls als Speicherstoff in R. rubrum bekannten Polysaccharids konnte vor allem bei großem Substratüberfluß und Inkubation unter Stickstoff beobachtet werden; es wurde jedoch auch unter optimalen Bedingungen nur ein geringer Anteil der total aufgenommenen Brenztraubensäure zur Synthese dieses Speicherpolysaccharids verwendet.
    Notes: Summary Illuminated cells of R. rubrum assimilate pyruvate and use it for the ynthesis of different cell components. A sufficient supply of substrate and light energy provided, part of the pyruvate is built into storage products. If the cells are suspended in phosphate buffer and kept under an atmosphere of molecular hydrogen the formation of the β-hydroxybutyrate polymer is stimulated. An excess of substrate and incubation under molecular nitrogen leads to the synthesis ofa polysaccharide, also known as storage product in R. rubrum; but even under optimal conditions only a small part of the pyruvate is used for the synthesis of this storage polysaccharide.
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  • 28
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Es wird der Einfluß des Sauerstoffpartialdruckes auf die Bacteriochlorophyllsynthese und die Morphogenese des photochemischen Apparates von Rhodopseudomonas capsulata untersucht. 1. Die Wachstumsrate ist in aeroben, heterotrophen Dunkelkulturen in einem relativ weiten Bereich vom Sauerstoffpartialdruck unabhängig. Die Proteinverdopplungszeit beträgt in einem komplexen Medium bei 30° C und einem Partialdruck von 4–100 mm Hg, 2,5–2,75 std. Bei 150–160 mm Hg (pO2) im Medium wird das Wachstum ungefähr um 10% reduziert. Unterhalb eines kritischen Sauerstoffpartialdruckes von etwa 4 mm Hg bricht der oxydative Stoffwechsel zusammen und die Wachstumsrate nimmt demzufolge stark ab. 2. Die Rate der Bacteriochlorophyllsynthese in aeroben Dunkelkulturen wird vom Sauerstoffpartialdruck reguliert. Geringe Mengen an Bacteriochlorophyll (etwa 0,05 μg/mg Protein) sind auch in voll aeroben Kulturen enthalten (pO2 150 mm Hg). Ein Absenken des pO2 im Bereich von 100–20 mm Hg bewirkt nur eine sehr geringe Erhöhung des spezifischen BChl.-Gehaltes der Zellen. Eine Erniedrigung des pO2 unter 20 mm Hg hat einen starken Anstieg der BChl.-Syntheserate zur Folge. Nach 8 Std stellt sich ein konstanter Wert des spezifischen Bacteriochlorophyllgehaltes der Zellen ein, dessen Höhe vom pO2 abhängig ist. 3. Der spezifische Bacteriochlorophyllgehalt der intracellulären Membranen steigt nach Absenken des pO2 von 160 mm Hg auf 5 mm Hg nach 2 Std von 3,3 auf 33,9 μg BChl./mg Protein an. 4. Die Biosynthese des photochemischen Apparates von Rps. capsulata wird ebenfalls durch Absenken des Sauerstoffpartialdruckes gefördert. Aber die Kinetk ist von der der Bacteriochlorophyllsynthese verschieden. Der Anstieg der Photophosphorylierungsaktivität (PP) verläuft linear zum Proteingehalt der Membranfraktion. Dagegen nimmt das Verhältnis PP/BChl. nach einem kurzfristigen Anstieg ab. 5. Elektronenmikroskopische Aufnahmen von Dünnschnitten zeigen sowohl in voll aeroben Dunkelkulturen (pO2 150–160 mm Hg) als auch in semiaeroben Kulturen (pO2 etwa 5 mm Hg) intracelluläre Membranstrukturen. In aeroben Zellen sind vorwiegend tubuläre Strukturen ausgebildet, in semiaeroben Kulturen vesiculäre Thylakoide. 6. Die Ergebnisse zeigen, daß die Bacteriochlorophyllproduktion, die Biosynthese des photochemischen Apparates und die Thylakoidmorphogenese vom pO2 beeinflußt werden. Stärke und Verlauf der Synthesen werden aber unterschiedlich reguliert.
    Notes: Summary The influence of the oxygen partial pressure on the morphogenesis of thylakoids, the biosynthesis of bacteriochlorophyll, and the activity of photophosphorylation is investigated. 1. The growth rate (doubling time of protein) in aerobically grown dark cultures of Rhodopseudomonas capsulata is in a relative wide range independent of the oxygen partial pressure. The protein doubling time in a complex medium at 30° C amounts to 2.5–2.75 hrs in the range of 4–100 mm Hg (pO2). On conditions that the pO2 is saturated (150–160 mm Hg) the growth will be reduced about 10%. Underneath a critical oxygen partial pressure (4 mm Hg) the oxydative metabolism and the growth rate are strongly limited. 2. The rate of bacteriochlorophyll synthesis in the log phase of aerobic dark cultures is strongly related to the oxygen partial pressure. The production of bacteriochlorophyll comes to a maximum in the range of 3 to 5 mm Hg (pO2). But bacteriochlorophyll is produced up to 60–70 mm Hg (pO2). The rate of bacteriochlorophyll synthesis is relatively high below 20 mm Hg. 3. The production rate of bacteriochlorophyll is greatly enhanced when the oxygen partial pressure is suddenly lowered. Therefore the specific bacteriochlorophyll content of the cells (μg BChl./mg Protein) is strongly increased until a characteristic new level has been attained after 8 hrs. 4. The regulation of the bacteriochlorophyll synthesis in relation to the oxygen partial pressure in the medium is between 4 to 100 mm Hg (pO2) during log phase growth independent of the growth rate. 5. The biosynthesis of the photochemical apparatus (measured as photophosphorylating activity) of Rhodopseudomonas capsulata is increased likewise by lowering of the oxygen partial pressure. But the kinetic is different from that of bacteriochlorophyll synthesis. The increase in activity of light induced phosphorylation (PP) is enhanced lineary to the protein content of the membrane fraction. But the PP/bacteriochlorophyll ratio is decreased after a short increase. The bacteriochlorophyll content of the intracellular membranes is increased from 3.3 to 33.9 μg/mg protein two hours after induction (pO2: 160 mm Hg→5 mm Hg). 6. Micrographs of thin sections show intracellular membrane structures in high aerated (pO2 150–160 mm Hg) as well as in low aerated cultures (pO2 5 mm Hg). In aerobic cultures tubular membrane structures and in semiarobic cultures vesicular thylakoids (chromatophores) are to be seen. 7. The results demonstrate clearly that the production rate of the bulk of bacteriochlorophyll is not strictly paralled with the biosynthesis of the photochemical apparatus and the membrane morphogenesis.
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  • 29
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The endogenous respiration of 14C-labelled spores of B. cereus was measured through the 14CO2 produced, and the rate expressed as Q (μl CO2/hxmg). New upper limits for respiration in various conditions have been set. Dry spores had no measurable activity; Q〈10−4 at room temperature and 〈10−3 at 35° C. For wet spores of different harvests, at 30°C, Q lay between 0.0013 to 0.067. Near 40° C, respiration showed a maximum. Thermal history has a great influence on Q. CO2 production by heat-killed spores is attributed largely to infection. Water or 10−3 m sodium phosphate buffer (pH=6.5) gave equal spore respiration, in strong NaCl it was less. Azide enhanced respiration dramatically. A temporary increase was also found with non-radioactive glucose. Exogenous respiration of spores in glucose exceeded endogenous respiration. Endogenous and exogenous respiration of vegetative forms were much larger than those of spores and were time-dependent. The ratio of minimum (endogenous, dry spores) and maximum (exogenous, wet vegetative cells) respiration was at least 3x105.
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  • 30
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Gas-cylinder membranes and α-granules were isolated from cells of the blue-green alga,Anabaena flos-aquae D 124. Gas-cylinder membranes, which are 1,100 Å wide after isolation, show striations having a periodicity of 50 Å. The membranes appear globular in section with a spacing of about 40 Å between globules. There are strong indications that the globules are proteinaceous with molecular weights of 22,000±2,000. Possible homologies of these membranes with viral coat protein are discussed. α-granules were shown by a variety of techniques to be polysaccharide.
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  • 31
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    Archives of microbiology 65 (1969), S. 181-194 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Das Steroidantibioticum Fusidinsäure wurde in Kulturen von sechs Dermatophyten und vonCalcarisporium antibioticum, einer neubeschriebenen Art der Deuteromycetes, nachgewiesen. Das Vorkommen von Antibiotica bei Dermatophyten und das Spektrum der Fusidinsäure bildenden Pilze werden erörtert.
    Notes: Summary The steroid antibiotic fusidic acid was identified from six strains of dermatophytes and fromCalcarisporium antibioticum, a newly described species of the imperfect fungi. Antibiotic formation by dermatophytes and production of fusidic acid by fungi are discussed.
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  • 32
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    Archives of microbiology 65 (1969), S. 146-162 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Tyrosinase der Mutantezonata (z) vonPodospora anserina wurde untersucht. Die Mutante erzeugt im Vergleich zum Wildstamm große Mengen Tyrosinase.z ist eine morphologische Mutante mit rhythmischen Wuchs. Das Genz liegt auf dem rechten Arm der Koppelungsgruppe II und hat einen Abstand von 46 Kartierungseinheiten vom Centromer. Die Reinigung des Enzyms erfolgte durch Präzipitation mit Protaminsulfat, Ammoniumsulfat und anschließende Säulenchromatographie an DEAE-Sephadex und Hydroxylapatit. Die Einheitlichkeit des gereinigten Enzyms wurde in der Ultrazentrifuge und der Elektrophorese festgestellt. Das gereinigte Enzym ist in verdünnter Lösung instabil. Im Konzentrationsbereich von 2–15 mg/ml hat die Tyrosinase eine Sedimentationskonstante vons 20,w 0 =6,04. Die Molekulargewichtsbestimmung aus Diffusion und Sedimentation und aus dem Sedimentationsgleichgewicht nachYphantis ergab in demselben Konzentrationsbereich ein Molekulargewicht um 100.000. Bei einer Enzymkonzentration von 0,04 mg/ml fanden wir mit der Gelfiltrations-methode nur ein Molekulargewicht von 42.000. Aus diesen Resultaten läßt sich in Übereinstimmung mit den Ergebnissen an anderen Tyrosinasen aus Pilzen eine konzentrationsabhängige Assoziation und Dissoziation des Enzyms folgern. Der Kupfergehalt beträgt 0,214±0,008%. Das gereinigte Enzym hat ein Absorptionsmaximum bei 280 nm und eine Schulter bei 290 nm und von 320 bis 380 nm. Das Verhältnis von Dehydrogenierungen an Brenzcatechin zu Hydroxylierungen an Hydrochinon konnte polarographisch bestimmt werden. Es läuft im Mittel auf zwei Dehydrogenierungen nur eine Hydroxylierung ab. Natriumazid wirkt als reversibler und kompetitiver Inhibitor der Dehydrogenierungsreaktion. Im Rohextrakt liegt das Enzym in einer latenten Form vor. Es sind nur 10–20% der späteren Aktivität nachzuweisen. Das Enzym wird im Verlauf der Reinigungsprozedur oder durch Temperaturbehandlung (10 min bei 60°C) aktiviert. Der Aktivierungsvorgang ist von einer Veränderung der elektrophoretischen Beweglichkeit des Enzyms begleitet. Latentes und aktives Enzym unterscheiden sich nicht in ihrem Sedimentationsverhalten.
    Notes: Summary Tyrosinase of the mutantzonata (z) ofPodospora anserina was investigated. In comparison to the wild strain the mutant (z) produces large quantities of tyrosinase.z is a morphological mutant with rhythmic growth. The genez is localized on the right arm of linkage group II at a distance of 46 map-units from the centromere. The enzyme was purified by precipitation with protamine-sulphate and ammonium sulphate and by subsequent column-chromatography on DEAE-Sephadex and hydroxylapatite. The homogeneity of the purified enzyme was checked by ultracentrifugation and disc-electrophoresis. The purified enzyme is unstable in dilute solution. At a concentration of 2–15 mg/ml the tyrosinase has a sedimentation constant ofs 20,w 0 =6.04. The determination of molecular weight from sedimentation and diffusion constants and from sedimentation-equilibrium according toYphantis showed a molecular weight of approximately 100,000 in the same concentration range. At an enzyme concentration of 0.04 mg/ml we found a molecular weight of only 42,000 using the gel-filtration technique. From these results, in accordance with the results obtained from other tyrosinases in fungi, association and dissociation of the enzyme dependent on concentration may be concluded. The copper content reaches a level of 0.214±0.008%. The purified enzyme has an absorption maximum at 280 nm and a shoulder at 290 nm and from 320 to 380 nm. The quotient of catechol-dehydrogenations to hydroquinone-hydroxylation was determined polarographically. The mean ratio is two dehydrogenations to only one hydroxylation. Sodium azide acts as a reversible and competitive inhibitor of the dehydrogenation-reaction. In the crude extract the enzyme is found in a latent form. Only 10–20% of its later activity can be demonstrated. The enzyme is activated in the course of the purification procedure or by temperature treatment (10 min at 60°C). The activation process is accompanied by a change in the electrophoretic mobility of the enzyme. Latent enzyme and active enzyme do not differ in their sedimentation behaviour.
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  • 33
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    Archives of microbiology 65 (1969), S. 163-171 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Wärmeaktivierte Sporen, die im Gegensatz zu unvorbehandelten in Standard-Nährlösung zu mehr als 90% keimen, gehen, falls man nach der Aktivierung kein exogenes Substrat bietet, erneut in einen Ruhezustand über. Die dünnschichtchromatographische Analyse der in getrockneten, unvorbe handelten Sporen enthaltenen Zucker ergibt, daß dieses Sporenmaterial im wesentlichen nur Trehalose enthält (bis zu 35% des Trockengewichtes). Sofort im Anschluß an die Aktivierung setzt ein sehr rascher Trehalose-Umbau ein; Glucose tritt auf; sie staut sich vorübergehend im Sporeninnern an; darüber hinaus ist sie auch im Außenmedium reichlich nachzuweisen. Glucose-6-phosphat konnte bei dem hier verwendeten Arbeitsgang selbst bei aktivierten Sporen weder dünnschichtchromatographisch noch enzymatisch sicher erfaßt werden. Das bedeutet, daß der Abbau der Trehalose zu Glucose sehr stark durch eine Wärmebehandlung stimuliert wird, so stark, daß die Durchsatzkapazität folgender Systeme nicht ausreicht, um die anfallende Glucose umzusetzen; trotzdem ist die Leistungsfähigkeit z. B. der Systeme, die Glucose bis zu Brenztraubensäure abbauen, nach Aktivierung der Sporen wieder weitaus größer als die der Systeme des oxydativen Endabbaus, denn im Anschluß an eine Wärmeaktivierung kommt es, wie früher nachgewiesen, trotz stimulierter Atmung auch zu einem Stau verschiedener Glykolyse-Produkte.
    Notes: Summary Only 1–3% of untreated spores ofPhycomyces blakesleeanus germinate in a standard nutritive solution. These dormant spores can be activated by a heat shock (3 min 50°C) so that more than 90% germinate. Heat-activated spores not supplemented with substrate become dormant again. Some time ago we demonstrated that also a homogenate of dormant spores can be activated by higher temperatures; such a homogenate produces certain amounts of pyruvic acid and lactic acid. We analyzed the sugars in dried dormant spores and ca. 35% trehalose were found; other sugars we could not discover. Immediately after heat activation relative large amounts of glucose are found enzymatically in the spores and in the surrounding medium. Significant amounts of glucose-6-phosphate could not be measured. This leads us to the opinion that the stimulation of trehalose degradation to glucose after a heat activation is much faster than the following steps of glycolysis. But we don't think that the dormancy ofPhycomyces spores lies in their inability to utilize trehalose and that is mainly e.g. the activation of trehalases by heat which finally leeds to germination.
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  • 34
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Forty-one strains of non-sporulating sulfate-reducing bacteria were isolated from estuaries, deep sea and other saline environments. Their salinity requirements, utilization of significant carbon compounds, resistance against growth inhibition by Hibitane, optimal growth temperatures and growth temperature ranges were studied. The results include data on strains isolated from the Red Sea hot brine deep area. Basing on the determined characteristics the strains were identified as Desulfovibrio desulfuricans, D. vulgaris, D. salexigens, and D. desulfuricans var. aestuarii.
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  • 35
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    Archives of microbiology 65 (1969), S. 195-207 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Zellfreie Extrakte aus Fruchtkörpern von Agaricus bisporus katalysieren eine NADPH-abhängige Reduktion freier Fructose zu Mannitol. In vivo werden neben diesem Zucker auch andere Monosen in den Hexit eingebaut; die entsprechenden Inkorporationsraten sind jedoch gering (für Mannose 11%, Glucose 7% und Xylose 2%, bezogen auf diejenige von Fructose = 100%). Auch die Mannitolbildung aus Glucose erfolgt über Fructose als Zwischenprodukt, und ein alternativer Syntheseweg, Reduktion von Glucose zu Sorbitol und dessen Epimerisierung zu Mannitol beinhaltend, scheint nicht realisiert zu werden, obschon es gelang, Spuren von Sorbitol gaschromatographisch nachzuweisen. Im Kulturchampignon ist demnach freie Fructose als obligater Präkursor von Mannitol zu betrachten. Die experimentellen Resultate werden im Zusammenhang mit unseren gegenwärtigen Kenntnissen über den Kohlenhydratstoffwechsel von A. bisporus diskutiert.
    Notes: Summary In cell-free extracts of fruiting bodies of A. bisporus mannitol is shown to be synthesized by a NADPH-dependent reduction of free fructose. In vivo other monoses are also incorporated into the mannitol skeleton, but to a much lesser extent. Formation of this hexitol from glucose proceeds through fructose as an intermediate, whereas mannitol synthesis by a pathway involving reduction of glucose to sorbitol and epimerization of the latter to the polyol in question does not seem to occur, although it was shown that sorbitol exists in the common mushroom. Therefore, fructose would appear to be the obligate precursor of mannitol in this fungus. The experimental results are integrated into the picture of our present knowledge of carbohydrate metabolism in A. bisporus.
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  • 36
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    Archives of microbiology 65 (1969), S. 218-227 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The total DNA in species of blue-green algae is similar to that of bacteria on an individual cell, but not on a dry weight, basis. The % G+C content of DNA from four species of blue-green algae has been determined by melting temperature measurement. An attempt tomeasure genetic homology between blue-green algae and certain bacterial species is described.
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  • 37
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung 1. Eine Methode zur selektiven Isolierung von Curvularien und Helminthosporien wird beschrieben. 2. 29 Stämme von Curvularia lunata, 32 Stämme von 24 verschiedenen Curvularia-Arten und 18 Stämme von verschiedenen Helminthosporium-Arten wurden auf ihre Fähigkeit 6α-Fluor-21-acetoxy-16α-methyl-4-pregnen-3,20-dion (FMDOCA) zu verseifen und Reichstein-Substanz-S und FMDOC in 7α,9α11β und 14α Stellung zu hydroxylieren, untersucht. 3. Fast alle untersuchten Stämme können FMDOCA gut verseifen. 4. Zur 11β-Hydroxylierung mit hoher Ausbeute sind nur einige Stämme von Curvularia lunata und zwei Helminthosporium-Stämme befähigt. 5. In der Systematik und Morphologie ließen sich keine Parallelen zu den physiologischen Fähigkeiten dieser Stämme aufzeigen.
    Notes: Summary 1. A method for the selective isolation of Curvularia and Helminthosporium is described. 2. 29 strains of Curvularia lunata, 32 strains of 24 different Curvularia species, and 18 Helminthosporium strains are tested for their ability to saponify 6 α-Fluor-21-acetoxy-16α-methyl-4-pregnene-3,20-dione (FMDOCA) and to hydroxylate the free compound FMDOC and compound Reichstein S in the 7α,9α,11β und 14α position. 3. Almost all strains were able to saponify FMDOCA. 4. Only few strains of Curvularia lunata and two strains of Helminthosporium were able to hydroxylate compound RS or FMDOC in 11β position at interesting quantities. 5. In systematics and morphology no correlations with the physiologic abilities of these strains could be detected.
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  • 38
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Von Wildtyppopulationen von Hydrogenomonas H 16 und anderen Stämmen, die lediglich Fructose, aber nicht Glucose zu verwerten vermögen, wurden Glucose verwertende Mutanten isoliert. Sämtliche Mutanten stimmen in zwei Merkmalen überein: 1. sie bilden Glucose-6-phosphat-Dehydrogenase konstitutiv und 2. die Substratsättigungskurve der Veratmung von Glucose verläuft flacher als die für Fructose. Während die Atmungsrate bei 1,66 mM Fructose schon maximal ist, erreicht die Veratmung von Glucose bei 1,66 mM Glucose erst 15 bis 55%. Die Beziehungen zwischen diesen pleiotropen Effekten (Glucoseverwertung und konstitutive Bildung der Glucose-6-phosphat-Dehydrogenase) sind unbekannt.
    Notes: Summary Wildtype cells of Hydrogenomonas H 16 and of similar strains of Hydrogenomonas utilize only fructose; they are unable to use glucose as a carbon source. Mutants were isolated which are able to grow on glucose. Ten of these mutants were investigated and found to be similar with regard to the following properties: 1. they are constitutively derepressed for the formation of glucose-6-phosphate dehydrogenase, 2. the substrate saturation curve of the respiration of glucose is unlike of the fructose curve. While the respiratory rate with fructose as a substrate is already maximal at 1.66 mM fructose, the respiratory rate for glucose as a substrate (at 1.66 mM) amounts only to 15 to 55% of the maximal rate (substrate saturation). The relationships between these pleiotropic effects (glucose utilization and constitutive glucose-6-phosphate dehydrogenase) are unknown.
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  • 39
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    Archives of microbiology 67 (1969), S. 62-70 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cell differentiation in Anabaena cylindrica is accompanied with characteristic changes in the pigment composition of heterocysts and spores. In both the absence of phycocyanin is consistent with the lack of CO2-fixing ability previously reported. The presence of chlorophyll and β-carotene suggests a functional photosystem I in heterocysts. In the spores chlorophyll is largely replaced by pheophytin. The quantitative distribution of carotenoids is also affected. An increase in the proportion of β-carotene is characteristic of heterocysts while spores show a larger proportion of xanthophylls compared with the intact filament.
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  • 40
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    Archives of microbiology 67 (1969), S. 71-90 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mixed cultures of the amoebo-flagellate and the alga on which it feeds were examined by electron microscopy. Both amoeboid and flagellate stags were sectioned and their morphology described, particular attention being paid to the flagellar bases and to the intra-nuclear fibrils. The latter are discussed with relation to nuclear fibrils in other organisms. The amoeba is compared with other amoebae whose fine structure has been examined, and the possible phylogeny of Pseudospora is considered.
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  • 41
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    Archives of microbiology 67 (1969), S. 91-98 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Low concentrations of hydroxyurea stimulated the growth of the blue-green alga Anabaena variabilis that had been pretreated with sublethal concentrations of chloramphenicol or of certain nucleic acid base analogues. When supplemented to the culture medium, hydroxyurea also counteracted the growth inhibitory effect of chloramphenicol on this organism. In contrast, when A. variabilis cells grown in the presence of hydroxyurea were subsequently treated with chloramphenicol, they were found to have become highly susceptible to the growth inhibitory effects of chloramphenicol. The growth of hydroxyurea pretreated cells in basal medium was attended by a lag that was shorter than that of untreated controls; on the other hand, when hydroxyurea pretreated cells were inoculated into chloramphenicol-supplemented medium, they exhibited a longer lag than that shown by untreated cells in chloramphenicol. The results obtained are discussed in terms of the probable effects of hydroxyurea and chloramphenicol on certain enzyme systems.
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  • 42
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    Archives of microbiology 67 (1969), S. 128-140 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Studies on the degradation of 6,7-dimethylquinoxaline-2,3-diol-(methyl-14C) by Pseudomonas RF are described. Evidence is presented that this degradation product of riboflavin is assimilated by at least two different pathways which are affected by growth conditions. One leads to the previously identified 3,4-dimethyl-6-carboxy-α-pyrone and the other to intermediates which in turn are metabolized to various cell constituents. Analyses of amino acids from protein hydrolysates and organic acids excreted into the medium disclosed the presence of 14C-labelled alanine, butyrate, propionate and acetate, all predominantly labelled in the terminal methyl group. Results of studies with various inhibitors of the two pathways are given and the data are compared with previous work on this organism. A scheme for bacterial degradation of 6,7-dimethylquinoxaline-2,3-diol is postulated.
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  • 43
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung 1. Bei Hydrogenomonas H 16 wurden nach Mutationsauslösung mit salpetriger Säure etwa 0,4% und mit 1-Nitroso-3-nitro-1-methylguanidin 1,5% auxotrophe Mutanten unter den überlebenden Zellen gefunden. Um die Mutantenausbeute zu erhöhen, wurde eine Anreicherungsmethode ausgearbeitet. Die Penicillintechnik wurde dadurch modifiziert, daß anstelle des bei H 16 wirkungslosen Penicillins Colistin eingesetzt wurde. Eine 10stündige Einwirkung von 50 μg Colistin/ml überlebten im Modellversuch 88% der nichtwachsenden auxotrophen Zellen und nur 0,09% der wachsenden Wildtypzellen. 2. Es wurden 214 Mutanten isoliert und bezüglich ihres Nährstoffbedarfs charakterisiert. Neben auxotrophen wurden auch solche Mutanten isoliert, die Fructose nicht als C-Quelle zu verwerten vermögen. 3. Einige der isoleucin- und isoleucin-valin-bedürftigen Mutanten wurden eingehender untersucht. Kreuzfütterungs- und Enzymversuche lassen folgern, daß die Biosynthesewege für Isoleucin und Valin in Hydrogenomonas mit denen in anderen Bakterien identisch sind.
    Notes: Summary 1. Using cells of Hydrogenomonas H 16 after mutagenesis by nitrous acid about 0.4 percent and by 1-nitroso-3-nitro-1-methylguanidine 1.5 percent auxotrophic mutants were found among the survivors. In order to increase the mutant yield an enrichment method was elaborated. The penicillin technique was modified by replacing penicillin by colistine, since penicillin is ineffective for Hydrogenomonas H 16. The incubation of 108 cells/ml under growth conditions in the presence of 50 μg colistine/ml for 10 hrs was found effective; during a model experiment 88 percent of the non-growing auxotrophic cells and only 0.09 percent of the growing wildtype cells survived. 2. 214 mutants were isolated and nutritionally characterized. In addition to auxotrophs many mutants were isolated which lack the ability to utilize fructose. 3. Some of the strains requiring isoleucine, or isoleucine+valine were characterized. On the basis of results of crossfeeding experiments and of enzyme assays it is concluded that the biosynthetic pathways for isoleucine and valine in Hydrogenomonas are the same as in other bacteria.
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  • 44
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    Archives of microbiology 67 (1969), S. 110-127 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung An Rohextrakten aus Hydrogenomonas H 16 und davon abgeleiteten Mutanten wurden die regulatorischen Eigenschaften der Threonin-Desaminase und der Acetohydroxysäure-Synthase untersucht. 1. Die Aktivität der Threonin-Desaminase wurde nach zwei Verfahren im zusammengesetzten optischen Test an der NADH2-Oxydation gemessen: durch Umsetzung des entstehenden Ammoniaks mit Glutamat-Dehydrogenase zu Glutamat und durch Reduktion des entstehenden α-Ketobutyrats durch Lactat-Dehydrogenase zu α-Hydroxybutyrat. Das pH-Optimum liegt in Tris-Puffer bei pH 9,0. Die Desaminierungsreaktion wird bereits durch 0,3 mM L-Isoleucin vollständig gehemmt. Die Hemmung läßt sich durch L-Valin teilweise aufheben. Die Substrat-(Threonin)-Sättigungskurve hat paraboloiden, in Gegenwart von Isoleucin (0,05 mM) sigmoiden Verlauf. Der Hill-Koeffizient beträgt in Abwesenheit des Inhibitors n=1,1 und in Gegenwart von Isoleucin n=2,4 (pH 8,3). 2. Von einer isoleucin-auxotrophen Mutante, deren Threonin-Desaminase defekt ist, wurde eine prototrophe Revertante isoliert, die Isoleucin ausscheidet. Die Threonin-Desaminase dieser Mutante unterscheidet sich vom Wildtypenzym durch eine verminderte Affinität für Isoleucin; halbmaximale Hemmung erfolgt bei 2,5 mM Isoleucin gegenüber 0,2 mM beim Wildtypenzym. 3. Die Acetohydroxysäur-Synthase wird bei pH 9,0, dem pH-Optimum der katalytischen Aktivität, durch L-Valin zu 25% gehemmt; bei pH 7,4 bewirken 0,1 mM L-Valin eine 50%ige Hemmung. Die Hemmung ist spezifisch; L-Isoleucin und L-Leucin bewirken weder eine Aktivitätsminderung, noch wirken sie antagonistisch. 4. Während des Wachstums einer isoleucin-valin-auxotrophen Mutante im Chemostaten werden bei Wachstumsbegrenzung durch L-Valin beide Enzyme, die Threonin-Desaminase und die Acetohydroxysäure-Synthase, dereprimiert gebildet. Wachstumsbegrenzung durch Isoleucin führt zur Derepression der Bildung der Threonin-Desaminase.
    Notes: Summary Threonine desaminase and acetohydroxyacid synthase in cell-free extracts of Hydrogenomonas H 16 and mutants derived therefrom have been studied with respect to their regulatory properties. 1. The activity of threonine desaminase has been determined employing two combined optical tests using the oxidation of NADH2 as indicator system: by trapping the ammonia produced through glutamate dehydrogenase and α-ketoglutarate and by reducing the α-ketobutyrate produced through lactate dehydrogenase. Optimum pH has been found to be 9.0 in tris-buffer. The desaminase reaction is completely inhibited already by 0.3 mM L-isoleucine. The inhibition is partially relieved by L-valine. The substrate (threonine) saturation curve has paraboloid shape; in the presence of isoleucine (0.05 mM) its shape is sigmoid. The Hill-coefficient in the absence of the inhibitor is n=1.1 and in the presence of L-isoleucine is n=2.4 (pH 8.3). 2. A prototrophic revertant has been isolated from an isoleucine requiring mutant defective in threonine desaminase. This revertant excretes isoleucine. The threonine desaminase of this revertant differs from the wildtype enzyme by a diminished affinity for isoleucine; half maximal inhibition occurs at 2.6 mM isoleucine in contrast to 0.2 mM at the wildtype enzyme. 3. The acetohydroxyacid synthase has its pH optimum at 9.0. At this pH the inhibition by L-valine amounts to 25%. At pH 7.4 a 50% inhibition was observed at a 0.1 mM concentration of valine. By varying the magnesium concentration an 80% inhibition was observed at 0.2 mM valine. The sensitivity of the enzyme is specific for L-valine; L-isoleucine and L-leucine neither decrease the activity nor act antagonistically. 4. When an isoleucine-valine-auxotrophic mutant was grown in a chemostat and when growth was limited by the concentration of valine, the formation of both enzymes, threonine desaminase and acetohydroxyacid synthase, became derepressed. When growth was limited by the concentration of isoleucine only threonine desaminase became derepressed.
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  • 45
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cell-wall preparations of Streptomyces mediterranei ATCC 13685 and some of its phage resistant mutants contain only the meso isomer of the diaminopimelic acid. Arabinose was found to be always present in the hydrolysates. Based on studies of the cell-wall composition it is shown that S. mediterranei does belong to the genus Nocardia and its transfer to this genus is proposed.
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  • 46
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    Archives of microbiology 67 (1969), S. 156-165 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Boromycin, at a concentration of 0.05 μg/ml inhibits the synthesis of protein, RNA and DNA in whole cells of Bacillus subtilis. It is being antagonised by surface active compounds and is being bound to lipoprotein. Binding of the boromycin within the cell especially takes place at the cytoplasmic membrane. The inhibitory effect to Bacillus subtilis is being reversed by high concentration of potassium salts (e.g. 0.2 m KCl). The reversion is specific of potassium salts. After the adding of boromycin a discharge of potassium ions from the cells can be observed. The K+-Na+-activated ATP-ase of the cytoplasmic membrane is not influenced by boromycin. On an artificial membrane of carbon tetrachloride boromycin shows a low selectivity for potassium ions compared with sodium and lithium ions. The degradation of boromycin through alkaline and acid hydrolysis leads to a loss of antibiotic activity, due to the splitting off the boric acid from the molecule.
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  • 47
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Wirkung einer Reihe von Salzen auf die Aktivität der partikelgebundenen NADH-Cytochrom c-Reduktase aus Rhodospirillum rubrum wurde untersucht. Das Enzym wird durch die verschiedenen Salze unterschiedlich stark gehemmt. Bei einwertigen Anionen ist ein Zusammenhang zwischen dem Ionenradius und der Stärke der Hemmung zu erkennen. Zwei- und dreiwertige Anionen hemmen das Enzym mehr als einwertige. Zwei- und dreiwertige Kationen sind vergleichsweise sehr starke Inhibitoren. Bei allen untersuchten Ionen besteht eine Beziehung kompetitiver Art zwischen Cytochrom c und dem betreffenden Ion. Völlig analoge Ergebnisse werden bei der Bestimmung der Oxydation von Succinat mit Cytochrom c als Elektronenacceptor erhalten. Mit diesen Hemmungsexperimenten kann die Bildung eines Komplexes zwischen Cytochrom c aus Herzmuskel und den Phospholipiden der Elektronentransportpartikel von R. rubrum wahrscheinlich gemacht werden. Daraus ist zu folgern, daß der Komplex und nicht Cytochrom c allein der wirksame Elektronenacceptor für NADH- und Succinat-Cytochrom c-Reduktase ist.
    Notes: Summary The effect of a number of salts on the activity of the particulate NADH-cytochrome c-reductase of Rhodospirillum rubrum was investigated. The enzyme was shown to be inhibited by the presence of these salts. With monovalent anions a relationship between the size of the anion and its capacity of inhibition is observed. Di- and trivalent anions inhibit more than do monovalent anions. Di- and trivalent cations cause very strong inhibition of the enzymatic activity. With all ions a relationship of the competitive type exists between cytochrome c and the ion tested. Results identical to those described are obtained when the oxidation of succinate is measured with cytochrome c as the electron acceptor. With these inibition experiments it was shown that a complex between mammalian cytochrome c and the phospholipids of the electron transport particles of R. rubrum is likely to be formed and that this complex rather than cytochrome c itself is the electron acceptor for NADH- and succinate-cytochrome c-reductase.
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  • 48
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    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die lichtinduzierte Pigmentbildung wird in Abhängigkeit von verschiedenen Faktoren untersucht und ihre Kinetik gemessen. Der Farbstoff entsteht nur in einem stickstoffhaltigen Medium. — Der Temperaturbereich, innerhalb dessen Pigmentbildung möglich ist, liegt zwischen 14° und 39° C mit einem Optimum bie 29° C. — Für die Anfangskonzentration von Glucose im Medium wird ein Optimum bei 3% gefunden. Nach Verbrauch der Glucose hört die Farbstoffbildung auf, sofern nicht ein anderer Faktor begrenzend wirkt wie z. B. hohe Lichtintensität, durch die die Pigmentproduktion stark eingeschränkt, schließlich sogar völlig verhindert wird. In Abhängigkeit von der Lichtintensität findet sich ein Optimum der Pigmentbildung je nach Lichtsensibilität der Zellen zwischen 26 und 45 kerg · sec-1 · cm-2. Hohe Lichtintensität wirkt zerstörend auf bereits entstandenes Pigment. — Die Aktivität des pigmentbildenden Systems sowie die erreichbare Farbstoffendkonzentration hängen ferner vom Beginn der Belichtung ab. Nennenswerte Pigmentsynthese ist nur möglich bei einem Belichtungsbeginn innerhalb der ersten 10–12 Std und ist um so intensiver, je früher die Belichtung einsetzt. — Bei im übrigen günstigen Kulturbedingungen arbeitet das pigmentbildende System nur während der Lichteinwirkung. — Kinetische Untersuchungen der Farbstoffbildung zeigen, daß das Pigment im Medium entsteht und von dort in die Zellen aufgenommen wird. Demnach muß eine Synthese von Pigmentvorstufen in den Zellen und ihre Abgabe an das Medium angenommen werden.
    Notes: Summary Light-induced pigment synthesis by cells of Saccharomyces cerevisiae var. ellipsoideus is investigated under the influence of various factors, and kinetic studies of its formation are performed. Pigmentation only occurs with nitrogen in the medium. The temperature favouring pigment production ranges between 14° C and 39° C, and has its optimum at 29° C. Optimum glucose concentration in the medium is 3%. Pigment formation continues until glucose is completely exhausted provided that no other factor — as for instance high light intensity — limits pigment synthesis before. The lowest possible light intensity for pigment production was found at 3 kerg · sec-1 · cm-2, the optimum lies between 26 and 45 kerg ¢ sec-1 · cm-2 — depending on the light sensibility of the cells. Still higher light intensities finally destroy part of the pigment already formed. — There is a clear influence of the onset of light exposure a) on the activity of the pigment producing system and b) on the end concentration of pigment. Only cells exposed to light within the first 10–12 hours of culture give rise to considerable pigment synthesis which is the more active the more the onset of light approaches that of the culture. If all other factors are favourable the pigment producing system once working continues to do so only as long as light is on. —Kinetic experiments show the pigment to be formed in the medium and then to be incorporated by the cells. It must be concluded therefore that pigment precursors are synthesised in the cell and from there transferred into the medium.
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  • 49
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Im Anschluß an frühere Arbeiten wird in den vorliegenden Untersuchungen der Aminosäurestoffwechsel des Weizenrostes weiterverfolgt. Zunächst wurde geprüft, in welchem Ausmaß applizierte Aminosäuren in die Rostsporen aufgenommen und eingebaut werden. Die Aufnahme der gewählten Aminosäuren war schlechter als die von Glucose und Valeriansäure. Ein beträchtlicher Prozentsatz der inkorporierten Aminosäuren wurde zu CO2 oxydiert. Also sind die Aminosäuren—neben Fettsäuren und Glucose—in beträchtlichem Maße an der Atmung der Sporen beteiligt. Die Umsetzung der in den Sporen verbleibenden Anteile der inkorporierten Aminosäuren wurde verfolgt. Bei Applikation von Alanin-U-14C wurden freie Aminosäuren, organische Säuren und lösliche Kohlenhydrate markiert. Vornehmlich Glutaminsäure und Asparaginsäure wurden in großen Mengen gebildet, und die Proteine wurden durch sie stärker markiert als durch die anderen Aminosäuren. Valin, Leucin und iso-Leucin waren nur gering markiert, obwohl sie aus dem bei Alanininkubation hochradioaktiven Pyruvat entstehen. In der Fraktion der löslichen Kohlenhydrate waren außer Trehalose vier Zuckeralkohole stärker markiert, am stärksten Erythrit, schwächer Mannit, Glycerin und Arabit. Ihr Syntheseweg wird diskutiert. Bei Applikation von Glykokoll-U-14C findet sich fast keine Aktivität in löslichen Kohlenhydraten und organischen Säuren. Siegelangt vornehmlich in die Aminosäuren, besonders in Serin und Threonin, in geringem Maße in Alanin und noch schwächer in Glutaminsäure und Asparaginsäure. Die von zahlreichen Organismen bekannte Beziehung zwischen Serin und Glykokoll wird in den Rostsporen aufgezeigt. Die starke Markierung des Threonins deutet auf einen zweiten Syntheseweg des Threonins, an dem Glykokoll beteiligt ist. Die endogene Syntheserate dieser Aminosäuren ist sehr klein. Bei Applikation von Arginin-Guanidino-14C wird praktisch nur das freie und das gebundene Arginin markiert. Der Guanidino-Kohlenstoff des applizierten Arginins wird zu einem beträchtlichen Teil veratmet. Die endogene Syntheserate des Arginins ist sehr gering.
    Notes: Summary The metabolism of three amino acids in wheat rust uredospores was investigated by labeling with 14C-amino acids. While arginine was taken up better than alanine and this better than glycine, the uptake of all amino acids was not as efficient as that of glucose and valerate. With higher concentrations of amino acids in the medium remarkable amounts of amino acids were incorporated. The capacity for uptake of amino acids is not therefore a limiting factor in protein synthesis. A large amount of the incorporated arginine, alanine, and glycine was respired as CO2. This finding indicates that amino acids are used—besides fatty acids and glucose—as a substrate in respiration. The metabolic fate of the carbon skeletons of some amino acids was further followed. With alanine-U-14C labeling, most free amino acids, organic acids, and soluble carbohydrates were found to be labeled. In this experiment, glutamic and aspartic acids were formed in a higher concentration; both acids arising in the hydrolysis of the proteins were likewise strongly labeled. The high specific activity of glutamic and aspartic acids demonstrates the importance of the TCA cycle for the metabolism of the carbon skeleton of alanine. Valine, leucine and iso-leucine, which are metabolic derivatives of the highly labeled pyruvate (after incubation with alanine), showed only a low amount of 14C. It appears that only very small amounts of these amino acids were synthesized. Since all soluble carbohydrates were strongly labeled, high level of glucogenesis was indicated. Nearly no radioactivity was found in soluble carbohydrates and the organic acids. After the application of glycine-U-14C, however, the amino acids, especially serine and theronine and to a smaller extent glutamic and aspartic acids, were labeled. The metabolic relation between serine and glycine, known from many organisms, was demonstrated in the rust spores. The strong labeling of threonine indicates a second metabolic pathway leading to synthesis of threonine with the participation of glycine. The endogenous rates of synthesis of these amino acids are very small. Using arginine-guanidino-14C as a tracer only, free and bound arginine were markedly labeled. The guanidino carbon of the applied arginine was respired to a large degree. The endogenous rate of arginine synthesis is very low.
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  • 50
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Wir untersuchten elektronenmikroskopisch das periphere Membransystem und die Polyphosphatgranula in Schnitten von Nitrobacter winogradskyi und verglichen beide mit physiologischen Daten. Die Nitrit-Oxydationsaktivität ist abhängig von der Konzentration des Cytochroms c. Ganz allgemein haben Zellen mit einer hohen Aktivität eine große, solche mit einer niedrigen eine kleine Cytochrommenge. Entsprechend ändert sich der Membrangehalt. Aktive Zellen mit hohem Cytochromgehalt enthalten viele Membranen, inaktive mit geringem Gehalt nur wenige. Außerdem ist die Aktivität pro Cytochrommolekül nicht konstant. Zellen, die lange Zeit ohne Nitrit gestanden haben, besitzen eine niedrige, solche aus der logarithmischen Wachstumsphase eine hohe Umsatzrate. Die Ursache ist nicht bekannt. Die Zahl der Polyphosphatgranula steigt mit zunehmendem Gehalt an Polyphosphaten in der Bakterienzelle.
    Notes: Summary The peripheral membrane system and polyphosphate granules of Nitrobacter winogradskyi as they are revealed by sections studied in the electron microscope are regarded in relation to physiological data. The activity of nitrite oxydation depends on the concentration of cytochrome c. Cells being highly active generally show a relatively high amount of cytochrome c, whereas this is not the case in less active cells. The number of membrane pairs is affected simultaneously: active cells of high cytochrome concentration contain a high number of membrane pairs; those which are less active and have a lower cytochrome concentration, possess only a few membrane pairs. In addition the activity per mol cytochrome varies. Cells having been short of nitrite for a long time show a low turnover rate, whereas in the logarithmic phase of growth the turnover rate is considerably higher. The reason of this is not yet known. The number of polyphosphate granules increases in relation to the amount of polyphosphate found in the bacterial cell.
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  • 51
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    Archives of microbiology 69 (1969), S. 138-148 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Nach Behandlung mit 1-Nitroso-3-nitro-1-methylguanidin und nach Anreicherung in einem penicillinhaltigen Medium wurden von Hydrogenomonas facilis 35 Mutanten isoliert, die Uracil nicht mehr als N-Quelle zu nutzen vermochten. Eine Gruppe dieser Mutanten bildete keine Dihydrouracil-Dehydrogenase und verwertete Thymin, Orotsäure und Uracil nicht mehr. Eine zweite Gruppe hatte die Fähigkeit verloren, Dihydrouracil-Hydrase zu bilden und konnte Uracil, Orotsäure, Thymin, Dihydrouracil und Dihydrothymin nicht mehr verwerten. Während des Wachstums mit Cytosin wurde durch die erste Gruppe dieser Mutanten Uracil und durch die zweite Gruppe Dihydrouracil in das Nährmedium ausgeschieden. Die Enzyme Dihydrouracil-Dehydrogenase und Dihydrouracil-Hydrase waren in Zellen, die mit Cytosin, Uracil, Thymin oder Orotsäure angezogen worden waren, mit wesentlich höherer spezifischer Aktivität nachweisbar als in Zellen, die mit Ammoniumchlorid gewachsen waren. Dihydroorotsäure-Dehydrogenase und Dihydroorotsäure-Hydrase waren in den zellfreien Extrakten in keinem Fall nachweisbar. Die Befunde weisen daraufhin, daß Uracil und Thymin bei H. facilis durch eine unspezifische Dehydrogenase und Dihydrouracil und Dihydrothymin durch eine unspezifische Hydrase umgesetzt werden, und daß diese Enzyme in Gegenwart von Uracil, Thymin oder Orotsäure induktiv gebildet werden.
    Notes: Summary 35 mutant strains, unable to utilize uracil as a nitrogen source, were isolated from Hydrogenomonas facilis following treatment with 1-nitroso-3-nitro-1-methylguanidine and enrichment in a penicillin containing medium. One group of these mutants lacked dihydrouracil dehydrogenase and did not utilize thymine, orotic acid and uracil. A second group of mutants had lost the ability to form dehydrouracil hydrase and was unable to utilize uracil, orotic acid, thymine, dihydrouracil and dihydrothymine. The first group of these mutants excreted uracil, the second group dihydrouracil into the medium during growth with cytosine. The enzymes dihydrouracil dehydrogenase and dihydrouracil hydrase were present in much higher specific enzyme activities in cells grown with cytosine, uracil, thymine or orotic acid than in ammonia grown cells. Dihydroorotic dehydrogenase and dihydroorotase could not be demonstrated in cell-free extracts. These data indicate that both uracil and thymine are utilized as substrates by a non-specific hydrogenase and that both dihydrouracil and dihydrothymine are utilized by a non-specific hydrase. Both these enzymes are induced in presence of uracil, thymine or orotic acid in cells of Hydrogenomonas facilis.
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  • 52
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    Notes: Summary The nitrogenase activity (measured by reduction of C2H2 to C2H4) of nodules of Trifolium subterraneum grown at root temperatures from 7°C–19°C was broadly correlated with nitrogen fixation. Root temperature did not affect enzyme activity per se but did affect the amount of enzyme formed. Exposure of nodules to 7°C for 24 h did not decrease activity cf. 19°C. Activity was greatest when nodules were about 4 days old, before swollen bacteroid forms were produced, and then declined. The effectiveness of a bacterial strain at a given temperature was related to the amount of enzyme produced and to its persistence. Nitrogenase activity should be measured throughout the plant growth cycle for valid comparisons of strain effectiveness.
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  • 53
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    Notes: Summary 0761 05 1. The pathway of gluconate fermentation by C. aceticum has been investigated. Gluconate is degraded via 2-keto-3-deoxygluconate (KDG)1 and 2-keto-3-deoxy-6-phosphogluconate (KDPG) which is cleaved to yield pyruvate and glyceraldehyde-3-phosphate. 2. Gluconate dehydrase was present in high activity in cells grown on gluconate, but not in cells grown on fructose. The amounts of KDG kinase and KDPG aldolase in gluconate and fructose grown cells did not differ significantly. 3. The three enzymes involved in gluconate breakdown have been characterized with respect to their requirements for reducing agents and metal ions. Gluconate dehydrase requires a sulfhydryl compound and ferrous ions for activity, KDG kinase a divalent metal ion for activity. Sulfhydryl compounds and metal ions are not necessary for KDPG aldolase activity. 4. When suspensions of washed cells of C. aceticum fermented gluconate, KDG was accumulated in the medium.
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  • 54
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    Notes: Summary Catalase induction in Rhodopseudomonas spheroides and three locally isolated strains of Rhodopseudomonas (TL-1, TL-4 and Rps. D) was studied. A correlation between the rate of excretion of porphyrin and the inducibility of the culture was observed. 8-hydroxyquinoline at 4x10-5 M had no effect on Bchl synthesis but it inhibited porphyrin excretion and catalase induction in Rhodopseudomonas spheroides. 8-OH Q at this concentration partially inhibited Bchl synthesis and catalase induction in strain TL-1. The data indicate that the amount of catalase produced is dependent on the pool size of porphyrins.
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  • 55
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    Archives of microbiology 69 (1969), S. 180-196 
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    Description / Table of Contents: Zusammenfassung 1. Die von Näveke (1965) vorgeschlagene manometrische Methode zur Bestimmung des aus CO2 stammenden Anteils an der Gesamtkohlenstoffassimilation (=Kohlenstoffquotient) durch heterotrophe Bakterien wurde auf ihre Brauchbarkeit geprüft. 2. Am Beispiel des oxydativen Abbaues von Formiat durch Micrococcus denitrificans konnte gezeigt werden, daß die Methode zu beträchtlichen Fehlern führen kann, wenn bestimmte Bedingungen nicht eingehalten werden. 3. Durch Stabilisierung des pH-Wertes in der Zellsuspension und durch möglichst schnelle Herstellung des gewünschten CO2-Partialdrucks im Gasraum der Warburggefäße konnten die Fehlerquellen weitgehend beseitigt werden. 4. Unter den veränderten Versuchsbedingungen erreichte der Kohlenstoffquotient von M. denitrificans nach der Oxydation von Ameisensäure den Wert 1,0. 5. Hieraus konnte der Schluß gezogen werden, daß M. denitrificans seinen gesamten C-Bedarf vermutlich aus CO2 deckt, wenn die Energie dazu aus der Dehydrierung von Ameisensäure fließt. 6. Aus der O2-Einsparung bei der Oxydation von 20 μmolen Formiat in Gegenwart von CO2 ließ sich berechnen, daß dabei 13,9 μg C assimiliert werden. Die direkte Bestimmung des assimilierten C durch nasse Verbrennung der Bakterien führte zu ungefähr dem gleichen Betrag. 7. Daraus ließ sich ein Nutzeffekt der Formiatoxydation von etwa 10% berechnen.
    Notes: Summary 0950 08 1. The manometric method as described by Näveke (1965) used to determine the amount of entirely assimilated carbon derived from CO2 (=carbon-quotient) by heterotrophic bacteria was investigated for its usefulness. 2. With the example of oxidative decomposition of formate by Micrococcus denitrificans it has been demonstrated that the method can lead to considerable errors if certain conditions are not observed. 3. The sources of error could be eliminated extensively by stabilization of the pH-value in the cell suspension and by obtaining as soon as possible the wanted CO2-partial pressure in the gas room of the Warburg-vessels. 4. Under the modified conditions the carbon-quotient of M. denitrificans reached the value 1.0 after oxidation of formic acid. 5. From this it could be concluded that the entire carbon requirement of M. denitrificans is probably satisfied from CO2 if the energy is obtained from the dehydrogenation of formic acid. 6. From the O2-saving after the oxidation of 20 μmoles formate in the presence of CO2 it could be calculated that 13,9 μg C are thereby assimilated. The direct determination of assimilated carbon by wet combustion of the bacteria gave approximately the same result. 7. From this a free-energy efficiency of the formate-oxidation of about 10% could be calculated.
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  • 56
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    Notes: Summary The effect of inhibitors of carotenoid synthesis, diphenylamine, acridine, and acriflavin on catalase induction was studied in Rhodopseudomonas spheroides. The induction of catalase by 40 μM H2O2, was inhibited 5x10-4 M acridine, 5 μM acriflavin and 3x10-4 diphenylamine. Acridine, acriflavin and diphenylamine at 1.0x10-4 M, 1.5 μM and 5x10-5 M respectively, stimulated the induction. The stimulatory effect was shown to be at the transcriptional level rather than at the translational level. The concentration of acridine which stimulated the induction of the enzyme inhibited general protein synthesis in the cell, under similar conditions. Acriflavin also did not stimulate the induction of β-galactosidase in Escherichia coli B. It is suggested that these acridine dyes interact with the internal inducer-DNA complex which leads to a higher rate of production of catalase mRNA.
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  • 57
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    Archives of microbiology 65 (1969), S. 359-379 
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    Description / Table of Contents: Zusammenfassung Der Tyrosinstoffwechsel von 12 auf Peptonagar Melanin bildenden und 15 melaninfreien Kontrollstämmen der Species Pseudomonas aeruginosa wird untersucht. Es wird ein tyrosinfreies Ammoniumgluconat-Medium angegeben, auf dem bei gutem Wachstum aller Stämme keine Melaninbildung erfolgt. Ein Zusatz von Tyrosin oder seinen Precursoren gestattet eine deutliche Unterscheidung der Melaninbildner von den melaninfreien Stämmen innerhalb 16 Std. Die Melaninbildung wird durch Tyrosinasehemmer wie KCN, Na2S, Natriumdiäthyldithiocarbaminat usw. nicht beeinflußt. DOPA und DOPA chrom ließen sich in den Kulturextrakten nicht nachweisen. Es besteht keine Identität zwischen dem braunen Pigment und authentischem DOPA-Melanin. Sämtliche Melaninbildner zeigen eine Akkumulation von Homogentisinsäure mit nachfolgender Entwicklung eines anfangs roten, später braunen Pigmentes, während die melaninfreien Stämme keine Homogentisinsäure in nachweisbaren Mengen anhäufen. Unterbindet man die Melaninproduktion durch Anzüchtung der Keime auf tyrosinfreien Medien, so kommt es namentlich bei Zusatz von l-Tryptophan zu der für Pseudomonas aeruginosa typischen Anreicherung des Geruchsstoffes o-Aminoacetophenon und 4-Methylchinazolin. Die Hemmung des Chinazolinweges bei den Melaninbildnern wird mit der Tryptophanpyrrolase-Hemmung durch Hydrochinon verglichen. Die melaninbildenden Stämme der Species Pseudomonas aeruginosa sind nicht als tyrosinasehaltige Varianten aufzufassen, sondern als Verlustmutanten mit dem genetisch bedingten Defekt der Homogentisicase, ein Analogiefall zur Alkaptonurie.
    Notes: Summary Studies are performed on tyrosine metabolism of 12 melaninforming and 15 melanin-free strains of Pseudomonas aeruginosa grown on pepton agar. Melanin production does not occur in tyrosineless ammoniumgluconate medium. Addition of tyrosine or its precursors to this basis-medium allowed to distinguish between the melanin-forming and melanin-free strains within 16 hours. Inhibitors of tyrosinase such as KCN, Na2S, sodium-diethyl-dithiocarbaminate etc. are proved to be without influence on the pigment production. DOPA and DOPA-chrome are not present in the culture extracts. There is no identity between the isolated brown pigment and authentic DOPA-melanin. All melanin-forming strains are found to be remarkable by accumulating homogentisic acid followed by developing a red, later brown pigment, whereas the melanin-free strains do not concentrate homogentisic acid in detectable amounts. Preventing the melanin formation by growth on the tyrosineless basis-medium with addition of l-tryptophan the quinazoline pathway is employed again, which had been found inhibited during simultaneously occuring production of the brown pigment. Probably this effect may be caused by accumulated homogentisic acid similar to the inhibition of tryptophan-pyrrolase by hydroquinone. The melanin-forming strains of the species Pseudomonas aeruginosa are not regarded as variants containing a tyrosinase but as mutants with a genetic defect of homogentisicase in analogy to the alcaptonuria in metabolic diseases of men.
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    Archives of microbiology 65 (1969), S. 401-402 
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  • 59
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    Notes: Summary Trichomes of Microcoleus vaginatus, a motile blue-green alga of the family Oscillatoriaceae, were studied by light and electron microscopy in an effort to determine the sites of trichome breakage during production of hormogonia. According to the evidence presented herein, transcellular breakage of trichomes is the only mechanism of hormogonium production in M. vaginatus. Tearing of the murein sacculus appears to be necessary and sufficient for transcellular breakage to ensue. As Fuhs and earlier investigators have correctly claimed, this process always involves the death of the cell whose wall is torn. When trichomes of M. vaginatus break across cells to produce hormogonia, the murein sacculus usually tears along a circumferential set of junctional pores. This particular mechanism of trichome breakage is not universal among members of the family Oscillatoriaceae.
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    Archives of microbiology 69 (1969), S. 260-265 
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    Notes: Summary Non-infective pigmented variants of Rhizobium have been isolated from several cultures after treatment with antibiotics, heat and U.V. irradiation. These variants tolerated much higher doses of heat, U.V. and certain antibiotics than the wild type strains from which they originated. Some of the pigmented variants produced reverse mutants on subculture which had lost their pigment but recovered their infectivity. These reverse mutants also lost their extreme U.V.-resistance. However, many pigmented mutants were very stable and reverted only after U.V. irradiation. This investigation shows that pigmentation in Rhizobium and loss of ability to form nodules on the roots of leguminous plants are genetically linked and may be pleiotropic effects. So far, more than 10 pigmented variants have been isolated, none of them was infective, while reverse mutants which had lost their pigment always gave rise to nodules.
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    Archives of microbiology 69 (1969), S. 281-293 
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    Notes: Summary 1. The ultrastructure of frozen etched Nitrobacter winogradskyi cells was examined and compared with thin sections of chemically fixed cells. 2. Frozen etched cells showed two equally thick wall layers interconnected by short strands. This connection was weakened by a chemical prefixation treatment explaining the appearance of an intermediate electron-transparent layer in thin sections of chemically fixed cells. 3. Freeze etching revealed membrane surfaces carrying particles with an approximate diameter of 100 Å. Cytomembranes were also observed and showed a spatial arrangement similar to that described in chemically fixed cells. 4. In frozen etched cells the cytoplasm had an uniform granular appearance. When the cells were chemically prefixed the uniform granularity was disturbed by a partial coagulation of the cytoplasm. The same enclosures were identified in the cytoplasm of frozen etched cells as those reported in chemically fixed cells, i. e. PHB and polyphosphate storage granules.
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    Archives of microbiology 69 (1969), S. 294-300 
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    Notes: Summary Two phages isolated from Thermoactinomyces vulgaris multiplied optimally at 55–60°, and were inactivated at 80°. The two isolates had similar growth characteristics, host-range, serology and morphology. Tadpole-shaped with an elongated head, they resemble other actinophages, with long tail lacking contractile sheath and they seem specific to T. vulgaris.
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  • 63
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    Archives of microbiology 69 (1969), S. 266-280 
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    Description / Table of Contents: Zusammenfassung Zum ersten Male wird der Feinbau einer Cryptomonadacee des Meers in seinen Einzelheiten geschildert. Die Geißeln gleichen denen der anderen, bisher untersuchten Cryptomonaden; nur die Art der Einfügung ist vielleicht etwas einfacher. Die Ejectosomen (Trichocysten) haben die übliche Struktur, sind aber weniger zahlreich als bei den anderen Mitgliedern der Familie und Klasse. Die Chromatophoren enthalten zahlreiche Lamellen, deren jede aus zwei ziemlich dichten Thylakoiden zusammengesetzt ist. Ein einzelnes pyrenoid sitzt an den Chromatophoren. Ein zentraler Augenfleck ist an einem kurzen Fortsatz derselben befestigt. Chromatophoren, Pyrenoid und Augenfleck sind gemeinsam von einer endoplasmatischen netzigen Hülle (endoplasmatisches Reticulum) umhüllt. Zwischen dieser Hülle und den Chromatophoren werden Stärkekörner abgelagert. Der Zellkern ist in der Interphase unregelmäßig gestaltet. Er hat das übliche Aussehen der eukaryotischen Lebewesen. Am Vorderende sind zahlreiche umhüllte Bläschen, die wohl Abscheidungsorganellen sind. Der Feinbau von Chroomonas wird mit dem anderer Algen verglichen.
    Notes: Summary The detailed fine structure of a pigmented marine member of the Cryptophyceae is reported for the first time. The flagella are similar to those of other cryptomonads which have been studied but the root system is probably less complicated. The ejectosomes (trichocysts) have the typical structure but are present in fewer numbers than in many other members of the class. The chloroplasts contain numerous lamellae each composed of two rather dense thylakoids. A single large pyrenoid is attached to a chloroplast and on a short spur beyond this is the centrally placed eyespot. The chloroplasts, pyrenoid and eyespot are all enclosed by an endoplasmic reticulum sheath and starch grains are laid down between this sheath and the chloroplasts. The interphase nucleus is irregular in shape but has the typical eucaryotic appearance. At the anterior end of the cell are numerous coated vesicles which may have an excretory function. The fine structure of Chroomonas is discussed in relation to the ultrastructure of other algae.
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    Archives of microbiology 69 (1969), S. 301-313 
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    Notes: Summary The properties of a NADH dehydrogenase which was solubilized from the electron transport particulate fraction of R. rubrum by treatment with DOC were investigated. 1. The solubilized activity was further purified by DEAE-chromatography (total purification appr. 30fold). The purified enzyme preparation, because of its very low protein concentration, is extremely unstable. 2. The molecular weight of the solubilized enzyme, as determined by gelfiltration through Sephadex, is 75,000. 3. The solubilization increases the affinity of the enzyme for the electron aceptors, while the affinity for its substrate remains unchanged. 4. The enzyme is increasingly inactivated by dilution in buffer. 5. Incubation with the substrate NADH rapidly inactivates the enzyme. This inactivation is specific (NADPH inactivates only at much higher concentrations, NAD and NADP are without effect), it is complete and also irreversible. No protection can be achieved. 6. 2×10-4M PCMB or mersalyl completely inhibit the enzyme, EMI is without effect. There is no evidence for an inhibition, by PCMB or mersalyl when the system is pretreated with NADH (SH-group of Tyler et al., 1965). 7. o-phenanthroline is the only chelating agent found to interact with the NADH dehydrogenase. With only quantitative differences the properties given under 4.–7. are also shown by the membrane bound activity of NADH dehydrogenase, thus indicating a mild attack of DOC on the membranal structures and an easy, release of the enzyme.
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    Archives of microbiology 69 (1969), S. 330-342 
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    Notes: Summary The growth of several strains of Thiobacillus neapolitanus and of T. concretivorus was inhibited by l-phenylalanine. Inhibited T. neapolitanus organisms were unchanged morphologically and little altered in gross carbon content, but cultures growing in the presence of partially inhibitory concentrations of phenylalanine excreted more of the 14C fixed from 14CO2 than did control cultures. Phenylalanine inhibition could be reversed by tyrosine, tryptophan and several other amino acids. Tryptophan greatly stimulated the growth of T. concretivorus. 14C-phenylalanine was incorporated by T. neapolitanus and T. concretivorus, but was not converted to tyrosine. Phenylalanine depressed 14C-phenylalanine synthesis from 14CO2 by growing T. neapolitanus and also depressed 14C-tyrosine synthesis by non-growing organisms. Tyrosine and phenylalanine synthesis from 14CO2 was depressed by shikimate, and by their respective precursors p-hydroxyphenylpyruvate and phenylpyruvate. The well known branched pathway for aromatic amino acid biosynthesis was concluded to function in T. neapolitanus, and the probability that phenylalanine inhibited growth by interference with this pathway is discussed.
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    Archives of microbiology 69 (1969), S. 343-359 
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    Notes: Summary Incorporation of 14C-phenylalanine by T. neapolitanus was inhibited competitively by relatively low concentrations of glycine, serine, alanine, valine, leucine, isoleucine, tryptophan, tyrosine, histidine, threonine, and methionine (Group I amino acids), but not greatly depressed by aspartate, glutamate, lysine, arginine, cysteine (Group II amino acids) and proline at similar concentrations. Group I acids competed with each other for incorporation but were little affected by Group II acids. Similarly Group I acids little depressed the incorporation of Group II acids, among which, however, some mutual inhibition occurred. Incorporation of proline was depressed by both Group I and II acids. Two main permeation mechanisms are proposed, one transporting Group I acids, the other Group II acids, but some overlapping of function probably occurs. Proline may be transported by a third permease, which is subject to inhibition by both Group I and II acids. T. concretivorus also has a common transport mechanism for some amino acids. Less interaction between amino acids was found using two heterotrophic pseudomonads. Exogenous phenylalanine inhibited both the biosynthesis and the uptake of tyrosine and tryptophan by T. neapolitanus. High phenylalanine concentrations depressed the assimilation of 14C-labelled tyrosine and tryptophan less than low ones, suggesting that the bacteria developed a requirement for external tyrosine and tryptophan when exposed to highly inhibitory concentrations of phenylalanine.
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    Archives of microbiology 69 (1969), S. 314-329 
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    Description / Table of Contents: Résumé Les extraits de cultures anaérobies avec NO3 - de Micrococcus denitrificans et Pseudomonas aeruginosa catalysent la réduction du nitrite en N2 lorsqu'on les met en présence de p-phénylène-diamine ou de p-amino-N:N-diméthyl-aniline. Un atome de N2 est issu de-NH2; l'autre provient de NO2 - Quand la quantité d'extrait ou de cellules augmente, l'activité spécifique de l'enzyme, mesurée par la méthode manométrique de Warburg, décroît. La p-phénylène-diamine-NO2 --réductase est inhibée par le cyanure, présente une activité optimale à pH 6,6, existe à l'état soluble dans les extraits bruts: elle ne sédimente pas à 140 000×g pendant 2 heures. Elle précipite en majeure partie dans la fraction 45–70 (pour cent de saturation en sulfate d'ammonium). Chez M. denitrificans, elle est inductible et sa biosynthèse semble réprimée par l'oxygène. Les observations suivantes sugg⪻rent que la p-phénylène-diamine-NO2 --réductase joue un rôle dans la dénitrification: (1) jusqu'ici elle a été trouvée uniquement chez les bactéries dénitrifiantes; (2) les conditions de culture influencent de la même manière l'activité nitrite-réductase des cellules, mesurée en présence de glucose, et l'activité p-phénylène-diamine-NO2 --réductase des extraits; (3) les activités glucose (ou lactate)-NO2 --réductase et p-phénylène-diamine-NO2 --réductase des cellules ne sont pas additives. Lorsque la N:N:N′:N′-tétraméthyl-p-phénylène-diamine sert de donneuse d'électrons, les extraits produisent à la fois de l'oxyde nitrique et de l'azote.
    Notes: Summary Extracts of Microccus denitrificans and Pseudomonas aeruginosa grown anaerobically in the presence of NO3 - catalyze the reduction of nitrite to N2 when p-phenylene-diamine or p-amino-N:N-dimethyl-aniline is added. One atom of N2 originates from-NH2; the other from NO2 -. When the quantity of extract or of cells is increased, the specific activity of enzyme, measured by the Warburg manometric method, decreases. The p-phenylene-diamine-NO2 - reductase is inhibited by cyanide, has a pH optimum at 6.6, and in crude extracts exists in soluble form: it does not sediment at 140,000×g for 2 hours. The enzyme precipitates for the most part in the ammonium sulfate fraction 45–70. In M. denitrificans it is inducible and its biosynthesis seems to be repressed by oxygen. The following observations suggest that p-phenylene-diamine-NO2 - reductase has a role in denitrification: (1) until now it has been found only in denitrifying bacteria; (2) cellular nitrite reductase activity, measured in presence of glucose, and p-phenylene-diamine-NO2 - reductase activity of extracts are similarly infuenced by culture conditions; (3) the glucose (or lactate)-NO2 - reductase and p-phenylene-diamine-NO2 - reductase activities of cells are not additive. When N:N:N′:N′-tetramethyl-p-phenylene-diamine is used as electron donor, the extracts produce both nitric oxide and nitrogen.
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    Archives of microbiology 69 (1969), S. 360-369 
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    Notes: Summary DAHP synthetase (PODH lyase, EC4.1.2.15.) activity was demonstrated in undialysed and dialysed extracts of the wild type strain C and phenylalanine-resistant variant P4 of T. neapolitanus. Activity at pH 6.4 in extracts of both strains was inhibited at least 50% by 10-5 M phenylalanine. Strain C enzyme was inhibited at least 80% by 10-3M tyrosine, but was relatively unaffected by tryptophan. Tryptophan stimulated the P4 enzyme threefold at 10-5–10-4M. Inhibition of the P4 enzyme by phenylalanine could be virtually completely prevented by tyrosine or tryptophan, but these acids and histidine were much less effective in preventing inhibition of the strain C enzyme. Maximum activity in extracts of both strain C and P4 was obtained at pH 8.9, at which pH DAHP synthesis was 8 times greater than at pH 6.4. Activity at pH 8.9 in dialysed extracts of P4 showed K M values of 1.43×10-3 M and 4×10-3 M for E-4-P and PEP respectively. K i values for competitive inhibition by l-phenylalanine were 5.4×10-6 M and 1.45×10-5 M respectively for ranges of concentration of E-4-P and PEP. Inhibition of the growth of strain C by phenylalanine was concluded to be due to prevention of tyrosine and tryptophan synthesis through inhibitiom of DAHP synthesis. Resistance to phenylalanine was conferred on the mutant P4 by its possession of a system by which inhibition of DAHP synthesis by phenylalanine was prevented by tyrosine and tryptophan.
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    Archives of microbiology 67 (1969), S. 397-407 
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    Notes: Summary An investigation was made of the hydrocarbon-oxidising microorganisms in an upland moorland soil and the underlying shale band. The results obtained were in agreement with an earlier survey, although the methods used were not the same. The procedures used involve the assessment of numbers and activities of hydrocarbon oxidisers. The population studies were done, on this occasion, using the buried slide technique which, although simple to perform, did not always reveal the trends known to occur at the sites investigated. The metabolic activity of the micro-organisms was measured either respirometrically or by following the disappearance of the substrate. The respirometric methods were much less cumbersome and more sensitive to changes in the metabolic pattern in the samples. Of the two approaches the measurement of activity would appear to be the more useful since population studies yield no information on the rates at which micro-organisms are capable of degrading and thus removing contaminating oil from any given environment.
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    Archives of microbiology 68 (1969), S. 32-39 
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    Notes: Summary The ability to fix nitrogen of 10 strains of the yeasts Rhodotorula, Bullera and Torulopsis and 4 strains of Pullularia, all isolated from soils and some supplied by other investigators was examined using both the heavy nitrogen (15N2) and acetylene reduction techniques. Rigorous standards for aseptic culture, freedom from combined nitrogen and precision of analysis were maintained. No fixation was observed in any of the organisms and the ability of any eucaryote cell to fix nitrogen is doubted. Suggestions for the previous reports of fixation are made.
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    Archives of microbiology 68 (1969), S. 1-17 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung 1. In Robextrakten von Hydrogenomonas H 16 wurde die α-Isopropylmalat-Synthetase, das erste Enzym der Leucinbiosynthese, fluorometrisch nachgewiesen. Die Bildung des Enzyms wird durch Leucin reguliert. In Zellen, die unter Leucinmangel gewachsen waren, ist die Aktivität des Enzyms um das 21-24fache erhöht. Zugesetztes l-Leucin reprimiert die Bildung des Enzyms; die Aktivität war um 67% verringert. 2. Die α-Isopropylmalat-Synthetase wird im zellfreien Extrakt durch l-Leucin nicht-kompetitiv gehemmt. Bei pH 7,4, beträgt die maximal erreichbare Hemmung 93% der ursprünglichen Aktivität. Daneben wird das Enzym durch durch, die strukturanaloge Aminosäure des l-Leucins, dl-5′,5′,5′-Trifluorleucin bis zu 83% gehemmt. Andere geprüfte Aminosäuren üben keine Hemmwirkung aus. Sie können aber die durch l-Leucin verursachte Hemmung bei genügendem Überschuß völlig aufheben. Wirksam sind die Aminosäuren l-Valin, l-Isoleucin, dl-α-Aminobuttersäure, dl-Norvalin, dl-Norleucin und 1-Aminocyclopentan-carbonsäure (Cycloleucin). Die Aktivität der α-Isopropylmalat-Synthetase ist bei pH 8,0–8,4 am größten. Bei dem letzteren pH-Wert ist das Enzym völlig unempfindlich gegen l-Leucin. Die höchste Empfindlichkeit gegenüber l-Leucin liegt, bei pH 7,2. 3. Neben α-Ketoisovaleriansäure kondensiert das Enzym eine Reihe anderer α-Ketosäuren mit Acetyl-CoA. Die Bildung von α-Alkyläpfelsäuren wurde im zellfreien Extrakt durch den Einbau von 14C-markierter Essigsäure nachgewiesen. Gebildet wurden Äpfelsäure, α-Methyläpfelsäure, α-Äthyläpfelsäure, α-n-Propyläpfelsäure und α-Isobutyläpfelsäure. Die Bildung der Äpfelsäurederivate im zellfrein Extrakt wird durch, l-Leucin gehemmt.
    Notes: Summary 1. α-Isopropylmalate synthetase, the first enzyme of the leucine biosynthetic pathway, has been investigated in crude extracts of cells of Hydrogenomonas H 16 and of auxotrophic mutants derived therefrom. Quantitative measurements were based upon a fluorometric assay system. The synthesis of this enzyme is controlled by repression and derepression. In cells grown in the presence of l-leucine the enzyme activity amounts to a third compared to cells grown in minimal medium. When auxotrophic mutants requiring both valine and isoleucine for growth were grown with valine as the limiting factor, the enzyme activity was increased 24 fold; in leucine auxotrophic cells grown under limitation by leucine the enzyme activity was increased 21 fold compared to the wildtype grown in minimal fructose medium; the enzyme formed under conditions of derepression is not less stable than the enzyme formed in the wildtype. 2. α-Isopropylmalate synthetase in the crude extract of cells