Enhancement of ABE fermentation through regulation of ammonium acetate and D-xylose uptake from acid-pretreated corncobs

Abstract

Clostridium acetobutylicum TISTR 1462 and Clostridium beijerinckii TISTR 1461 were chosen to optimize acetone-butanol-ethanol (ABE) fermentation by using glucose as a carbon source. The enhancement in its productivity by adding various concentrations of ammonium acetate was studied. Then, the variation of glucose/xylose ratios in the pregrown mediumwas investigated. The results showed that both increased ammonium acetate in the production medium and D-xylose in the pre-grown medium could produce moreABE. With these conditions, using corncob hydrolysate as a substrate, 20.58 g/L ABE was produced from C. beijerinckii TISTR 1461 with 0.44 g/L/h and 0.45 of ABE productivity and yield, respectively. © Springer-Verlag Berlin Heidelberg and the University of Milan 2013.