[Dependence of Bacillus subtilis cell respiration on monovalent cations].

Nigericin, monensin, valinomycin + carbonyl-cyanide-m-chlorophenylhydrazone and gramicidin inhibit the respiration of Bacillus subtilis cells incubated with NAD-dependent substrates or succinate, but not with ascorbate + N,N,N',N'-tetramethyl-p- phenylene-diamine. The level of inhibition was decreased by potassium ions and, in a lower degree, by sodium or ammonium ions. The results obtained suggest that the respiration of Bacillus subtilis depends on the presence of monovalent cations whose effects seem to be directed at complexes I, III and probably complex II of the respiratory chain.