[Change in the level of SH-compounds in Escherichia coli and Bacillus subtilis cultures during transition to the stationary phase].

The redox potential "jump" recorded earlier for aerobic Escherichia coli and Bacillus subtilis cultures passing to the stationary phase was shown to result from a rise in the content of SH-compounds in the medium and on the cell surface. The effect was absent from anaerobic cultures as well as aerobic E. coli cells treated with the protonophore CICCP. Apparently, the elevated content of SH-compounds outside the cell upon starvation is part of the process which leads to a shift in the ratio between low-molecular-mass thiols and disulfides (towards disulfides inside the cell and towards thiols outside the cell) and is associated with a drop in the intracellular pH. Therefore, the entire metabolism of the cell can change as a result of reactions with the SH-groups of functionally significant compounds when the cell enters the stationary phase upon starvation.