Starter populations as determined under steady state conditions

Abstract

AbstractContinuous cultures of some heterotrophic Spirilli (Sp. serpens, Sp. curvatum, Sp. sp.) exhibit threshold concentrations of lactate, the growth limiting carbon and energy source, around 15 mg./l. This value corresponds to a threshold population density of 0.92 mg. dry weight/l. at a dilution rate of D = 0.185 hr.−1 (= 0.5 maximum growth rate). The minimum population density, which is regarded as equivalent to the starter population in batch culture, was dependent on the growth rate and the redox potential. The existence of minimum populations and the pronounced effect of population density on growth at low nutrient levels seem to be widespread phenomena closely related to growth under suboptimal conditions.