The expression of a Pichia stipitis xylose reductase mutant with higher K(M) for NADPH increases ethanol production from xylose in recombinant Saccharomyces cerevisiae.

摘要: Xylose fermentation by Saccharomyces cerevisiae requires the introduction of a xylose pathway, either similar to that found in natural xylose-utilizing yeasts Pichia stipitis and Candida shehatae or bacterial pathway. The use NAD(P)H-dependent XR NAD(+)-dependent XDH from P. creates cofactor imbalance resulting xylitol formation. effect replacing native with mutated increased K-M for NADPH (Kostrzynska et al., 1998: FEMS Microbiol Lett 159:107-112) was investigated ethanol recombinant S. strains. Enhanced yields accompanied decreased were obtained strains carrying XR. Flux analysis showed harboring utilized larger fraction NADH reduction. overproduction resulted an yield 0.40 g per gram sugar consumption rate 0.16 biomass hour chemostat culture (0.06/h) 10 g/L glucose as carbon source. (c) 2005 Wiley Periodicals, Inc. (Less)