Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (3)
  • Alginate  (1)
  • Arachidonic acid  (1)
  • Brassica campestris  (1)
  • Springer  (3)
  • 1995-1999  (3)
  • 1960-1964
Collection
  • Articles  (3)
Publisher
  • Springer  (3)
Years
Year
Topic
  • 1
    ISSN: 1573-5044
    Keywords: Brassica campestris ; B. napus ; B. oleracea ; cell division ; cell wall regeneration ; cotyledon protoplasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Protoplasts isolated from cotyledons of a number of cultivars of Brassica napus, B. campestris and B. oleracea were cultured in different media to study the characteristics of cell wall regeneration and cell division at early stages of culture. Time course analysis using Calcolfluor White staining indicated that cell wall regeneration began in some protoplasts 2–4 h following isolation in all cultivars. 30–70% of cultured cotyledon protoplasts exhibited cell wall regeneration at 24 h and about 60–90% at 72 h after the initiation of culture. Results also indicated that a low percentage (0.4–5.4%) of cultured cotyledon protoplasts entered their first cell division one day after initial culture in all twelve cultivars. The percentage of dividing cells increased linearly up to 40% from 1 to 7 day, indicating that cotyledon protoplasts of Brassica had a high capacity for cell division. Factors that influence the level of cell wall regeneration and cell division during cotyledon protoplast culture have been investigated in this study. Cotyledons from seedlings germinated in a dark/dim light regime provided a satisfactory tissue source for protoplast isolation and culture for all Brassica cultivars used. The percentages of protoplasts exhibiting cell wall regeneration and division were significantly influenced by cultivar and species examined, with protoplasts from all five cultivars of B. campestris showing much lower rates of cell wall regeneration than those of B. napus and B. oleracea over 24–120 h, and with the levels of cell division in B. napus cultivars being much higher than those in B. campestris and B. oleracea over 1–9 days. The capacity of cell wall regeneration and cell division in cotyledon protoplast culture of the Brassica species appears under strong genetic control. Cell wall regeneration in protoplast culture was not affected by the culture medium used. In contrast, the composition of the culture medium played an important role in determining the level of cell division, and the interaction between medium type and cultivars was very significant.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1572-9699
    Keywords: Arachidonic acid ; isolation ; Mortierella ; soil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Malt extract agar and an incubation temperature of 5 °C were used to selectively isolate representatives of the genus Mortierella from soil. Fungi in a soil sample from mountain grassland able to grow under these conditions, amounted to a total of 2640 colony forming units per gram soil. Circa 94% of the total fungal isolates represented Mortierella subgenus Mortierella. The rest of the colony-forming units consisted of Mucor isolates (6.0%) and higher fungi (1.5%). All the Mortierella isolates produced arachidonic acid.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1573-5176
    Keywords: Alginate ; pilot plant process ; extraction ; Macrocystispyrifera ; filtration ; centrifugation ; flocculation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of temperature (70, 80, 90 °C) and time (1–9 h) during the alkaline extraction step on alginate yield and quality were studied. The alginate yield increased with time and maximum yield was obtained after 3.5 h treatment, ranging from19.4% at 70 °C to 21.9% at 90 °C. The viscosity of the alginate produced was inversely correlated with the temperature and time. At70 °C the slope of the curve was almost zero(753 to 923 mPa s); at 90 °C the viscosity loss was 154 mPa s per hour during the first two hours, reducing from 523 to 86 mPa s after 5 h; 80 °C yielded values between those for 70 °C and90 °C. The best conditions for alkaline extraction were using pH 10 at 80 °C for two hours. The curves obtained gave useful information for controlling the viscosity of the alginate during production. It was found that viscosity of the paste formed during alkaline extraction (`process viscosity') was the best parameter to determine there action rate during extraction. Alginate yield increased during filtration time from 17.6% to 23.7%after 55 min at 70 °C. In this step the viscosity of the alginate obtained remained almost constant (522–610 mPa s), indicating no degradation of the products during filtration. The best dilution to filter the alginate extract was obtained at 45 mPa s. Diatomaceous earth (Celite) and expanded lava(Perlite) were tested as filter aids. Expanded lava was the best filter aid, using 1 kg per kilogram of alginate produced. Three methods were studied to separate the alkaline-insoluble residues after extraction: filtration, centrifugation, flocculation, and combinations of them. The best system found was filtration with flocculant in a rotary vacuum filter, with a knife advance of 0.1 mm every 3.5 seconds and drum rotation of 2 rpm, yielding an average filtration flow rate of 10.5 L min-1.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...