葡萄糖对树干毕赤酵母发酵木糖的影响

对树干毕赤酵母Pichiastipitis间歇发酵和连续发酵木糖葡萄糖混合液进行了研究。结果表明，间歇发酵时葡萄糖对木糖发酵影响较小，当发酵液中葡萄糖质量浓度小于10．0g·L^-1时，树干毕赤酵母同步发酵利用葡萄糖和木糖。连续发酵木糖和葡萄糖时，葡萄糖对木糖发酵影响较大，以30．0g·L^-1葡萄糖和15．0g·L^-1木糖为发酵底物，当稀释率D=0．08h^-1时，木糖利用率为9．40％，乙醇质量浓度为12．55g·L^-1；当稀释率D=0．04h^-1时，木糖利用率达66．07％，乙醇质量浓度达16．93g·L^-1。图2表2参12

Ethanol fermentation with xylose and glucose mixtures and Pichia stipitis

Using vegetable fibre to ferment ethanol can relieve energy crunch and improve environment protection. Here batch and continuous fermentation of xylose and glucose mixtures with Pichia stipitis were studied to provide basis for industrialized fermentation of ethanol. P. stipitis was cultured in a single-stage reactor with a mixture of 10.0, 20.0, 30.0, 40.0, 50.0, 60.0g·L^-1 glucose and 5.0, 10.0, 15.0, 20. 0, 25.0, 30. 0, 60. 0 g·L^-1 xylose. Results showed that with a residual glucose concentration of not more than 10. 0g·L^-1 in a culture medium with batch fermentation, glucose and xylose could be fermented by P. stipitis synchronously. Then, for continuous ethanol fermentation, glucose had great effect on fermentation with xylose. When P. stipitis was cultured in a single-stage reactor with a mixture of 30.0 g·L^-1 glucose and 15.0 g·L^-1 xylose , at a dilution rate of 0. 08 h^-1, 9.40% of the xylose was consumed, and the ethanol concentration was 12.55g·L^-1. However, when the dilution rate was 0. 04 h^-1, 66.07% of the xylose was consumed, and the ethanol concentration was 16.93 g·L^-1 [Ch, 2 fig. 2 tab. 12 ref. ]