两株高效代谢木质纤维素稀酸水解物产乙醇的酵母特性及耐毒研究

对实验室筛选出的两株高效代谢木质纤维素稀酸水解液产乙醇的酵母菌Y1(Candida tropicalis)和Y4(Issatchenkiaorientalis)的乙醇发酵特性及耐毒能力进行了的研究。以未经任何脱毒处理的木质纤维素稀酸水解液为发酵底物进行乙醇发酵(原位脱毒乙醇发酵)。结果表明,Y1和Y4均能在24h内将水解液中所有的葡萄糖消耗完,乙醇产率分别为0.49g/g和0.45g/g,分别达到了理论值的96.1%和86.0%。在含有不同浓度梯度的糠醛及5-羟甲基糠醛的模拟水解液中,Y1和Y4能耐受的最高糠醛浓度均为5.0g/L,最高的5-羟甲基糠醛浓度均大于7.0g/L,当两种抑制剂等量混合时,两株菌能耐受的最高浓度为4.0g/L。两株菌均有较好的乙醇发酵及耐毒能力。该研究结果为木质纤维素水解液的原位脱毒发酵生产然料乙醇奠定了基础。

CHARACTERISTICS OF TWO YEAST STRAINS FOR ETHANOL PRODUCTION FROM DILUTE-ACID LIGNOCELLULOSIC HYDROLYSATE IN SITU DETOXIFICATION

Two inhibitor-tolerant ethanologenic microorganisms Y1 and Y4 isolated in our lab defined as Candida tropica-lis and Issatchenkia orientalis , respectively, were presented. When dilute-acid lignocellulose hydrolysate without detoxifi-cation was used as substrate, both isolates Y1 and Y4 consumed all the glucose within 24h with ethanol yield of 0.49g/g and 0.45g/g corresponding to the theoretical maximum value of 96.1% and 86.0%, respectively. In the defined medium supplemented with furfural and 5-HMF individually or combination at various concentrations, cell growth and ethanol fer-mentation of both isolates were investigated. The two strains tolerated 5.0g/L of furfural, or 7.0g/L of 5-HMF, and 4. Og/L furfural and 5-HMF combined . The isolates Y1 and Y4 showed the tolerance to furfural and 5-HMF with a high eth-anol yield. They have the potential to be used in ethanol production from biomass hydrolysates in situ detoxification.