Abstract:

An excellent strain, Candida shehatae TZ8-13, was attained by separating and purifying from initial Candida shehatae TZ1. Xylose, glucose and glucose-xylose mixtures ( at 60 g/L of total sugar) were fermented by the strain TZ13 for producing ethanol. The results indicated that xylose and glucose can be fermented efficiently by the strain TZ8-13. The ethanol yields are 21.6 g/L and 24.2 g/L respeetively when the concentrations of both xylose and glucose are 60 g/L, and the utilization rates of xylose and glucose are up to 97.81% (72 h) and 99.13% (36 h), respectively. The ethanol yield and utilization rates of xylose as sole carbon source of the screened strain TZ13 are increased by 55.38% and 19.54%, repectively, compared with the initial strain TZ1. Glucose as carbon source is prior to xylose. When the concentration ratio of glucose to xylose is 1, the ethanol yield is 22.8 g/L.

Key words: Candida shehatae TZ8-13, xylose, glucose, ethanol