Adaptation of glycolysis and growth to acetate in Sporolactobacillus sp. Y2-8

Exogenous addition of a low concentration of acetate (2 g/L sodium acetate) effectively decreased acetic acid excretion and lowered the ATP content in Sporolactobacillus sp. Y2-8 without any growth defect although the acetate could not be utilized at an initial glucose concentration of 150 g/L. This induced an enhanced glycolytic flux with increased specific activities of hexokinase and phosphofructokinase, probably to compensate for the lowered efficiency of ATP production. However, with increasing concentrations (5 g/L sodium acetate), acetate was utilized first before being produced again, causing a growth lag at the transition. Glucose consumption was also reduced at high acetate concentrations, resulting in decreased D-lactic acid production. These results demonstrate that acetate plays a significant role in regulating glycolysis and growth of Sporolactobacillus.