提高Pichia stipitis乙醇耐受和抑制剂耐受能力的菌种驯化

Pichia stipitis ADAPTION FOR INCREASING ETHANOL AND INHIBITOR TOLERANCES

为实现对汽爆预处理玉米秸秆未脱毒直接酶解和发酵产乙醇,对Pichia stipitis菌种进行提高乙醇耐受和抑制剂耐受能力的驯化。通过逐步提高底物葡萄糖浓度和发酵抑制剂浓度的方法,Pichia stipitis的乙醇和抑制剂耐受能力得到明显提高。结果表明:驯化菌株能在36h内将188.96g/L的葡萄糖代谢完全,乙醇浓度达到88.39g/L,乙醇产率为0.47g/g,达到理论值的92.2%;在含有不同浓度梯度的糠醛模拟水解液中,驯化菌株能耐受的最高糠醛浓度达到5.34g/L,乙醇产率0.45g/g,占理论值87.8%。利用该驯化菌株可进一步开展对未脱毒汽爆酶解液直接发酵研究工作。

In order to produce ethanol from zymohydrolysate of non-detoxified steam-exploded corn stalk, the Pichia stipitis strain was adapted for improving its abilities of ethanol-tolerant and inhibitor-tolerant. The data showed that the adapted strain expressed much higher toxin-tolerance and ethanol-tolerance than the parent. The adapted strain used up 188.96g/L glucose in 36h to get the ethanol yield of 0.47g/g with ethanol concentration of 88.39g/L, and corresponding to 92.2% of the maximum theoretical value. In various concentrations of simalation hydrolyze ligaid of furfural the adapted strain tolerated 5.34g/L furfural at most the ethanol yield of 0.45g/g corresponding to 87.8% of the maximum theoretical value. The adapted strain can be used to research direct fermentation of zymo-hydrolysate of non-detoxified steam-exploded corn stalk to ethanol.