Screening of Ethanol-producing Yeasts by Xylose Fermentation

[Objective] The aim was to screen yeasts which could produce ethanol by xylose fermentation.[Method]Yeasts which could produce ethanol by xylose fermentation were screened from natural environment by taking xylose as sole carbon source,furthermore fermentation performances of obtained strains were determined.[Result] Four strains like C4,C5,H5 and M2 were obtained,among them C4 had the highest fermentation efficiency of xylose(38%) within 24 h,while M2 had the highest yield of ethanol(0.438 g/L).Because procusts would be consumed by yeasts with the increase of fermentation time during the process of xylose fermentation so that the conversion efficiency of material was decreased,the fermentation time shouldn't be too long.[Conclusion] Combining with the change tendency of xylose conversion efficiency with fermentation time,the fermentation performance of M2 is the best.