Maximum specific growth rate
Springer Online Journal Archives 1860-2000
Abstract The growth characteristics of an obligately psychrophilic Vibrio sp. have been studied in a chemostat with glucose or lactose as the limiting substrate over a temperature range 0–23°C. Vibrio AF-1 has an optimum growth temperature of 15°C and maximum growth temperature which is dependent upon the carbon source. On glucose growth ceases at 20°C whereas on lactose growth continues to 23°C. Growth rate is also a function of the carbon source provided. When grown on glucose, fructose, sucrose, maltose and galactose μmax values of 0.046 h-1 at 15°C were recorded whereas on lactose, mannose, ribose and xylose μmax values of 0.020 h-1 were obtained. Substrate affinities (K s ) for the 9 sugars also fall into 2 divisions as for μmax and are temperature dependent. Those sugars which support a high growth rate have highest K s values at 0°C whereas these which give a low growth rate show maximum affinities at 15°C. Vibrio AF-1 produces the maximum cell yield (0.6 g/g sugar consumed) at temperature 〈8°C irrespective of the carbon source utilised and correlated with maximum rates of sugar uptake and minimum O2 consumption. Maintenance energy determination on glucose grown cells show that at 2° C 2% of the carbon input is used for maintenance whereas at 20°C the requirement increases to 10% of the carbon input.
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