Improving fructose utilization and butanol production by Clostridium acetobutylicum via extracellular redox potential regulation and intracellular metabolite analysis.

Improving fructose utilization and butanol production by Clostridium acetobutylicum via extracellular redox potential regulation and intracellular metabolite analysis. Biotechnol J. 2017 Jul 21;: Authors: Chen LJ, Wu YD, Xue C, Bai FW Abstract Jerusalem artichoke (JA) can grow well in marginal lands with high biomass yield, and thus is a potential energy crop for biorefinery. The major biomass of JA is from tubers, which contain inulin that can be easily hydrolyzed into a mixture of fructose and glucose, but fructose utilization for producing butanol as an advanced biofuel is poor compared to glucose-based ABE fermentation by Clostridium acetobutylicum. In this article, the impact of extracellular redox potential (ORP) on the process was studied using a mixture of fructose and glucose to simulate the hydrolysate of JA tubers. When the extracellular ORP was controlled above -460 mV, 13.2 g/L butanol was produced from 51.0 g/L total sugars (40.1 g/L fructose and 10.9 g/L glucose), leading to dramatically increased butanol yield and butanol/ABE ratio of 0.26 g/g and 0.67, respectively. Intracellular metabolite and q-PCR analysis further indicated that intracellular ATP and NADH availabilities were significantly improved together with the fructose-specific PTS expression at the lag phase, which consequently facilitated fructose transport, metabolic shift towards solventogenesis and carbon flux redistribution for butanol biosynthesis. The...
Source: Biotechnology Journal - Category: Biotechnology Authors: Tags: Biotechnol J Source Type: research