C.shehatae TZ8耐乙醇菌株的筛选及发酵性能研究

Screening of alcohol tolerant Candida shehatae and its fermentation characteristics

以C.shehataeTZ8为出发菌株,利用1%溶壁酶和1%蜗牛酶酶解1.5h,制备成C.shehataeTZ8原生质体,并对原生质体进行紫外诱变,以含不同浓度乙醇的木糖液体培养基培养进行初筛和复筛,获得一株遗传性能稳定、耐乙醇能力达5.5%(v/v)的菌株C.shehataeTZ8-4,比初始菌株耐乙醇能力提高了2%。对突变株C.shehataeTZ8-4发酵性能的研究结果表明:C.shehataeTZ8-4发酵糖能力从80g/L(葡糖糖和木糖比为2∶1)提高到120g/L,最大乙醇产量从27.41g/L提高到43.12g/L。

The protoplasts of C. shehataeTZ8 were obtained by lywallzyme and snail enzymes. Lywallzyme and snail enzymes concentration was both 1%. Enzymatic hydrolysis time was 1.5h. Ultraviolet radiation was used to mutagenize the protoplasts of Candida shehataeTZ8 for screening high ethonal concentration tolerance strain. Combining further screening experiments on cultivation with different ethanol yield in xylose-culture, a mutant strain C. shehataeTZS-4 was eventually obtained. Its alcohol tolerance degrading achieved 5.5% and increased by 2% compared with that of original strain. The genetic property of mutant strain was genetic stable Its ability of degrading glucose/xylose mixtures （ G： X =2：1 ） was improved from 80 g/L to 120 g/L Ethanol yield increased from 27.41 g/L to 43.12 g/L