The Role of Carbonate in the Metabolism of Glucose by Butyrivibrio fibrisolvens

Abstract

The amount of Na2CO3 added to semi-synthetic medium determined the length of the lag phase, the growth rate and the dry weight of 3 strains of B. fibrisolvens (wv1, NOR37, B835). With increasing CO32- concentration the molar growth yield of bacteria, from glucose, was increased and, of the fermentation products, formate increased more than the other acids. CO32--limited cultures of strain wvl (Group 2 Butyrivibrio) and strain NOR37 (Group 1 Butyrivibrio) incorporated 14CO32- into lactate and formate. In NOR37, lactate and formate had equal specific activities; in wv1, the formate specific activity was twice that of lactate. Strain wv1 had an active pyruvate synthase and an energy-dependent exchange between CO32- and formate was demonstrated. In strain wv1 butyrate was produced mainly from glucose.