Deletion of FPS1 , Encoding Aquaglyceroporin Fps1p, Improves Xylose Fermentation by Engineered Saccharomyces cerevisiae

• DOI: 10.1128/aem.00490-13
• Publication Date: 2013-03-09T04:12:19Z
• Authors: Na Wei; Haiqing Xu; Soo Rin Kim; Yong-Su Jin
• Keywords: Xylose metabolism; Metabolic Engineering

Accumulation of xylitol in xylose fermentation with engineered Saccharomyces cerevisiae presents a major problem that hampers economically feasible production biofuels from cellulosic plant biomass. In particular, substantial due to unbalanced redox cofactor usage by reductase (XR) and dehydrogenase (XDH) leads low yields ethanol. While previous research focused on manipulating intracellular enzymatic reactions improve metabolism, this study demonstrated new strategy reduce formation increase carbon flux toward target products controlling the process secretion. Using xylitol-producing S. strains expressing XR only, we determined role aquaglyceroporin Fps1p export characterizing extracellular xylitol. addition, when FPS1 was deleted poorly xylose-fermenting strain XDH activities, yield decreased 71% ethanol substantially increased nearly four times. Experiments our optimized also showed deletion reduced 21% 30% 3% 10% under various conditions. Deletion consumption rate anaerobic conditions, but effect not significant at high cell density. resulted higher concentrations did significantly change NAD(+)/NADH ratio strains. The results demonstrate is involved present gene target, FPS1, mechanism different those previously reported engineer yeast for improved fermentation.