Influence of pH and initial lactate concentration on the growth of Lactobacillus plantarum

Abstract

Fermentation yields of Lactobacillus plantarum were measured at controlled pH between 4.0 and 8.0 and initial lactate concentrations of 0-90 g/l. Optimal growth conditions at pH 6.0 without addition of lactate gave a growth rate of 0.57 h-1 and 20 g dry biomass/mol ATP formed (YATP). The pH variations resulted in a decrease in growth rate but the effect on YATPwas insignificant. The addition of lactate to the medium at 0 h resulted in linear decrease in the growth rate of the culture, and all the metabolic activities were completely inhibited at 110 g/l. The YATPand biomass/ substrate yield (YX/S) remained fairly steady up to 33 g lactate/l, beyond which both yields decreased considerably. © 1991 Springer-Verlag.