Effects of NADH-preferring xylose reductase expression on ethanol production from xylose in xylose-metabolizing recombinant Saccharomyces cerevisiae

► Cofactor-imbalance is a problem in xylose metabolism by recombinant S. cerevisiae. ► NADH-preferable XR, NAD-dependent XDH and XK were overexpressed in S. cerevisiae. ► Balanced expression of xylose metabolic enzymes reduced a major byproduct, xylitol. ► TAL expression and ALD6 deletion enhanced ethanol production from xylose considerably.