Effect of methionine sulfone on the growth of Citrobacter intermedius C3 (author's transl)]

Specific activity of glutamate dehydrogenase (GD) and glutamate synthase (GtS) has been determined in the wild strain C3 and on a non excreting pro- mutant strain. Methionine sulfone shows inhibitory effects on their growth. The addition of alpha-ketoglutarate to the medium prevents the inhibitory effect and increases the GtS specific activity in both strains. The physiological effect of methionine sulfone and its suppression by alpha-ketoglutarate is discussed.