基因组改组技术选育耐高温、耐高乙醇酿酒酵母菌株的研究

Study of Breeding Saccharomyces cerevisiae with Improved Temperature and Ethanol Tolerance by Genome Shuffling

摘要:

当以 f4、f5、f6作为出发菌株，用酵母菌原生质体紫外诱变的方法，在不同温度下，用含有不同浓度乙醇的平板筛选，分别获得了在耐高温和耐乙醇性状有较大提高的f4.2、f5.1、f6.2、f4.5等正突变菌株。以这些菌株作为出发菌株，进一步用硫酸二乙酯诱变，获得了f5.1.1、f4.2.1两个乙醇耐受性能较高的菌株。在建立了上述不同突变株后，通过基因组改组(genome shuffling)的方法，将上述不同特性的菌株经过两轮genome shuffling，获得了耐高温性能和耐乙醇性能都较好的酵母菌株。经过摇瓶发酵后证明，R24株在35℃发酵过程中，发酵液中的最高乙醇浓度12.93%（W/V），比原始出发菌株f4在35℃的发酵液中最高乙醇浓度8.11%提高了近5%。

Abstract:

By UV induced mutagenesis of protoplasts of Saccharomyces cerevisiae strain f4, f5 and f6, and screening on plates containing different concertration of ethanol at different temperature, we obtained improved strains, such as f4.2,f5.1, f6.2, f4.5. By using a DES to deal with all the improved strains, We obtained two mutants, f5.1.1 and f4.2.1,which have improved ethanol torlerance. We made use of genome shuffling to generate improved strains in this work. We shuffled twice these improved strains by protoplast fusion and finally obtained strains with higher temperature and ethanol tolerance. we also identified shuffled strains that produced more ethanol by shake-flask experments. At the 35℃, the ethanol yield of R24 strain got to 12.93% (W/V), and were almost 5% higher than that of stain f4.