NITRATE REDUCTION BY PYRUVATE IN CLOSTRIDIUM PERFRINGENS

Abstract

Pyruvate-dependent nitrate reduction was observed in crude extractsprepared from Clostridium perfringens grown with nitrate. This reduction system was reconstituted, under nitrogen gas with ferredoxin (Fd), nitrate reductase (NaR) and fraction A which was previously isolated from a crude extract of the cells. Rubredoxin (Rd) functioned as an electron carrier in place of Fd. Fd was reduced with fraction A in the presence of coenzyme A (CoA) and pyruvate, indicating that the fraction A contains pyruvate: Fd oxidoreductase. We propose the following scheme for the electron transfer in pyruvate-dependent nitrate reduction system in C. perfringens: pyruvate→pyruvate: Fd oxidoreductase→Fd (Rd) →NaR→ nitrate.