[Effect of glutamic acid oversynthesis on the development of cyanide-resistant respiration in the bacterium...

The composition of the respiratory chains of the wild stain Corynebacterium glutamicum and of its mutant differing in their ability for the glutamic acid oversynthesis in a medium with melassa was studied. Under excess of biotine and the parent strain is incapable of acid oversynthesis, while the mutant forms and excretes the acid. Both bacterial strains contain menaquinone and equal sets of cytochromes C550, b556, b563, and a600. The membrane-bound dehydrogenases of the parent strain are represented by NADH-, NADPH- and succinate dehydrogenases. Unlike the parent strain, the mutant membrane preparation does not oxidize NADPH. Both strains do not practically differ in their menaquinone content. The cyanide-resistant oxidase of a non-cytochrome nature appears in the wild strain during its transfer to the stationary growth phase. Induction of glutamic acid oversnythesis by addition of penicilline prevents the formation of the cyanide-resistant oxidase. On the contrary, the mutant transfer to the stationary growth phase is not accompanied by a formation of cyanide-resistant oxidase, which appears only after cessation of glutamic acid oversynthesis. Induction of the cyanide-resistant respiration by addition of cyanide inhibits the acid oversynthesis. Oxidation of substrates by membrane preparations of both bacterial strains in the absence and presence of cyanide is not followed by the hydrogen peroxide formation. It is assumed that there exist competitive interactions between the supersynthesis of glutamic acid and the cyanide-resistant respiration. The possible structure of the respiratory chain of Cor. glutamicum is discussed.