Xylose fermentation is essential for ethanol production from lignocellulosic biomass.Exposure of the xylose-fermenting yeast Candida shehatae(C.shehatae)CICC1766 to atmospheric pressure dielectric barrier discharge(DBD)air plasma yields a clone(designated as C81015)with stability,which exhibits a higher ethanol fermentation rate from xylose,giving a maximal enhancement in ethanol production of 36.2%compared to the control(untreated).However,the biomass production of C81015 is lower than that of the control.Analysis of the NADH(nicotinamide adenine dinucleotide)-and NADPH(nicotinamide adenine dinucleotide phosphate)-linked xylose reductases and NAD+-linked xylitol dehydrogenase indicates that their activities are enhanced by 34.1%,61.5%and 66.3%,respectively,suggesting that the activities of these three enzymes are responsible for improving ethanol fermentation in C81015 with xylose as a substrate.The results of this study show that DBD air plasma could serve as a novel and effective means of generating microbial strains that can better use xylose for ethanol fermentation.
