Butyrate production from carbon monoxide by Butyribacterium methylotrophicum

Abstract

Carbon monoxide is produced in high concentrations by gasification of coal or biomass, and is a potentially inexpensive feedstock for biological processes. A number of anaerobic microorganisms metabolize carbon monoxide, with acetate, hydrogen, or methane being the primary reduced products. The CO strain of Butyribacterium methylotrophicum was previously shown to grow on carbon monoxide as the sole carbon and energy source, with acetate being the primary product. This paper demonstrates that by modifying culture conditions, the carbon and electron flow of B. methylotrophicum can be manipulated to yield butyrate as the major product. A butyrate concentration of 6 g/L was obtained in batch culture with continuous addition of 100% carbon monoxide. The significance of this fermentation for fuels and chemicals production from carbon monoxide is discussed. © 1989 Humana Press Inc.