利用木糖高产乙醇酵母菌的ARTP诱变选育

Saccharomycete Fermenting Xylose to Ethanol and Its ARTP Mutation Breeding

摘要:

为了提高酵母菌利用木糖发酵产乙醇的能力，将分离得到的野生菌株异常威克汉姆酵母A42通过常温常压等离子体（ARTP）技术进行诱变处理，从中选育具有优良性能的高产乙醇突变菌株。结果表明：诱变处理时间120 s为最佳诱变条件，在该条件下对A42进行诱变，此时致死率达到97.53%。对该条件下ARTP诱变后的菌株进行两轮的筛选得到突变菌株A42-338，发酵60 h乙醇含量为20.78 g/L，其乙醇产量较出发菌株提高了42.59%，且传代8次各代乙醇产量变化率不超过2.50%。将异常威克汉姆酵母A42-338在油茶籽壳发酵培养基中发酵60 h乙醇含量为19.88 g/L，还原糖残糖含量为9.06 g/L，其中木糖残糖含量为1.79 g/L，葡萄糖残糖含量为7.27 g/L，木糖利用率为84.61%，葡萄糖利用率为81.05%，糖转化率为0.40 g乙醇/g糖。因此，ARTP诱变是一种高效可行的酵母菌育种方法。

Abstract:

In order to improve the ability of saccharomycete to produce ethanol by xylose fermentation, the wild strain of Wickerhamomyces anomalus A42 was mutated by normal temperature and atmospheric pressure plasma technology (ARTP), and a high ethanol producing mutant strain with excellent performance was selected. The results showed that the best mutation condition was 120 s, under this condition, the lethal rate of A42 was 97.53%. The results showed that the ethanol yield of A42-338 was 42.59% higher than that of the original strain, and the ethanol content was 20.78 g/L after 60 h of fermentation, and the change rate of ethanol production of each generation was not larger than 2.50% after 8 passages. The results showed that the content of ethanol and reducing sugar of A42-338 were 19.88 g/L, 9.06 g/L, 1.79 g/L, 7.27 g/L, 84.61%, 81.05% and 0.40 g ethanol/g sugar respectively. Therefore, ARTP mutation is an efficient and feasible method for yeast breeding.