Continuous production of mixed alcohols and acids from carbon monoxide

Abstract

Continuous, steady-state fermentations using carbon monoxide gas as the sole carbon and energy source have been achieved with the CO strain ofButyribacterium methylotrophicum. Fermentation pH was found to regulate carbon monoxide metabolism over the pH range of 6.8 to 5.0. Cell growth diminished at low pH, with washout occurring at pH 5.0. As observed previously in batch culture, lower pH values favored production of butyrate over acetate. The mechanism responsible for this trend is currently being investigated by quantification of key intracellular enzyme activities.