The role of carbonate in the metabolism of glucose by Butyrivibrio fibrisolvens.

The amount of Na2CO3 added to semi-synthetic medium determined the length of the lag phase, the growth rate and the dry weight of three strains of Butyrivibrio fibrisolvens (WV1, NOR37, B835). With increasing CO3(2-) concentration the molar growth yield of bacteria, from glucosewas increased and, of the fermentation products, formate increased more than the other acids. CO3(2-)-limited cultures of strain WV1 (Group 2 Butyrivibrio) and strain NOR37 (Troup 1 Butyrivibrio) incorporated 14CO3(2-) 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 CO3(2-) and formate was demonstrated. In strain WV1 butyrate was produced mainly from glucose.