[ATP pool in Propionibacterium shermanii cells under various culture conditions]

During batch cultivation of Propionibacterium shermanii in a medium with glucose, ATP content in the cells (nmoles per 1 mg of dry biomass) increased up to the middle of the log phase, and decreased abruptly by the end of the log phase. When the culture was grown in a medium with lactate, the maximal level of ATP (3 nmoles/mg) was lower than in a medium with glucose (5 nmoles/mg). Nitrogen starvation of the culture was accompanied with a decrease in the level of ATP. If ammonium sulphate was added to such a culture, first the level of ATP increased and then the growth began. Addition of ammonium sulphate, after 72 h, to the nitrogen--deficient culture, the original density of whose cell suspension was over 0.25 mg/ml, did not induce the growth, although the level of ATP also increased.