The Mechanism of Propionic Acid Formation by Clostridium propionicum

Summary: Clostridium propionicum evidently possesses a mechanism for the conversion of lactate to propionate different from that found in the previously studied propionic acid producing bacteria. Reactions common to certain propioni-bacteria and Veillonella gazogenes which could not be demonstrated with Cl. propionicum include: (a) the decarboxylation of succinic acid; (b) the fermentation of malate and fumarate; (c) the variation in the ratio of acetic to propionic acid according to the concentration of CO2; (d) the fixation of CO2 in propionic acid.