Rôle des acides aminés soufrés dans la croissance de Corynebacterium sepedonicum (Spieck. et Kott.) Skapt. et Burkh.

Abstract

Corynebacterium sepedonicum requires organic sulfur for its growth. In potato host tissue, the normal source of sulfur for the bacterium is methionine. The l isomer is more readily metabolized than the d isomer or the dl racemic mixture, but four derivatives, methionine sulfoxide, DL-methionine-CH3-sulfonium Cl, acetyl- and alanyl-methionine are more efficiently metabolized than any of the methionine isomers. Homocysteine and cystathionine, intermediates in methionine metabolism, are rapidly metabolized in the presence of trace amounts of methionine. Another intermediate, S-adenosylmethionine, has no effect on the bacterial growth. Ethionine and α-methylmethionine are not metabolized by C. sepedonicum and cystathionine or homocysteine cannot overcome the inhibitory effect of α-methylmethionine on growth of the organism.