树干毕赤酵母和酿酒酵母耦合发酵高浓度混合糖产乙醇

Coupled Fermentation of High-concentration Mixed Sugars by P. stipitis and S.cerevisiae to Produce Ethanol

研究在高浓度发酵底物下,不同木糖及葡萄糖之间的比例、P.stipitis CBS5773和S.cerevisiae的发酵先后启动顺序、两菌间的协同发酵对两菌共同发酵混合糖产乙醇的影响。结果表明,乙醇的产量主要来自于由S.cere-visiae消耗葡萄糖而产生,两菌株偶联发酵时,S.cerevisiae能较快启动进入产乙醇发酵而不受P.stipitisCBS5773生长的抑制;在高浓度(200 g/L)糖浓度下,S.cerevisiaee和P.stipitis CBS5773存在相互拮抗作用,S.cerevisiae并不完全抑制P.stipitis CBS5773的生长;当木糖与葡萄糖之比为3∶2,且S.cerevisiaee和P.stipitis CBS5773分开接入,发酵12 h,乙醇产量最大,达到57 g/L。

The effects of different ratio of xylose and glucose, the fermentation start-up sequence of P. stipitis CBS5773 and S.cerevisiae, and the cooperative fermentation of the two yeasts on ethanol production from mixed sugars were investigated in conditions of high-concentration fermenting substrate. The results showed that ethanol was produced mainly by glucose consumption via S.cerevisiae, S.cerevisiae was faster in fermentation start-up in coupled fermentation process and such start-up would not be inhibited by P. stipitis CBS5773 growth, S.cereviaiae and P. stipitis CBS5773 presented mutual antagonism under high sugar content （200 g/L）, and S.cerevisiae would not completely inhibit the growth of P. stipitis CBS5773. The maximum ethanol yield could be achieved （57 g/L） if the ratio ofxylose and glucose was 3：2, S.cereviaiae and P. stipitis CBS5773 inoculated respectively, and fermentation time was 12 h.