Production of 2,3-butanediol by newly isolated Enterobacter cloacae

Enterobacter cloacae NRRL B-23289 was isolated from local decaying wood/cor n soil samples while screening for microorganisms for conversion of L-arabi nose to fuel ethanol. The major product of fermentation by the bacterium wa s meso-2,3-butanediol (2,3-BD). In a typical fermentation, a BD yield of 0. 4 g/g arabinose was obtained with a corresponding productivity of 0.63 g/l per hour at an initial arabinose concentration of 50 g/l. The effects of in itial arabinose concentration, temperature, pH, agitation, various monosacc harides, and multiple sugar mixtures on 2,3-BD production were investigated . BD productivity, yield, and byproduct formation were influenced significa ntly within these parameters. The bacterium utilized sugars from acid plus enzyme saccharified corn fiber and produced BD (0.35 g/g available sugars). It also produced BD from dilute acid pretreated corn fiber by simultaneous saccharification and fermentation (0.34 g/g theoretical sugars).