Succinic Acid Production by Rumen Bacteria II. Radioisotope Studies on Succinate Production by Ruminococcus Flavefaciens

Abstract

Strain C of R. flavejaciens ferments [1_14C]glucose with the production of methyl-labelled succinic and acetic acids, and the specific activity of the succinic acid produced is one-half that of the substrate. Fermentation of glucose in the presence of [14C]bicarbonate gives rise to carboxyl-labelled succinic acid. Formic acid is also labelled, either by direct exchange with 14C02 or by exchange of 14C02 with the carboxyl group of pyruvate. These results are compatible with the formation of succinate from glucose via the Embden-Meyerhof pathway and carboxylation of pyruvate or phosphoenolpyruvate.