Reversal of pyruvate oxidation in Clostridium butyricum.

The failure to detect an equilibrium between acetyl phosphate, a product of pyruvate cleavage, and pyruvate has been one of the poorly understood observations of the pyruvate cleavage reactions in Clostridium butyricum and in Escherichia coli (l-3), although pyruvate synthesis from acetyl phosphate was reported in the latter organism (4). In the preceding paper (5) a small incorporation of acetyl-lCY-CoA into pyruvate was observed with extracts of C. butyricum. Since these extracts rltpidly equilibrate CO?. with the carboxyl group of pyruvate (3), the poor reversibility of the elastic system appears to lie in the nature of the oxidative portion of the reaction. Peck and Gest (6) have found that the electron transport system in these extracts may be activated by sodium hydrosulfite. The following report deals with pyruvate formation from acetyl phosphate and COZ in extracts of C. butyricum and the stimulation of this reaction by sodium hydrosulfitc.