啤酒酵母突变株发酵性能比较及随机扩增多态DNA分析

对9株啤酒酵母菌种及经过诱变获得的突变株进行了发酵试验，比较了不同菌株的发酵能力、产高级醇能力、双乙酰还原能力以及菌株稳定性。同时利用随机引物对不同啤酒酵母株的基因组DNA进行了随机扩增多态DNA（RAPD）分析，比较不同突变株之间基因组的分子差异。结果表明：不同酵母发酵14d后外观发酵度在72．3％-76．8％，其中酵母YZB具有较高的发酵能力，最终发酵产物的高级醇含量最低，双乙酰峰值最低为0．36mg／L，而酵母Y1110最终发酵产物的高级醇含量最低为67．4mg／L，但双乙酰峰值达0．41mg／L，后酵结束后这2株酵母的双乙酰均可降至0．1mg／L以下。菌株稳定性实验结果表明，在传代7次以后和第1代的主要性能没有明显变化。利用随机引物OPG-5对不同酵母的基因组进行RAPD分析，酵母Y1110、YZB和YZD可以通过特异的扩增谱带区别于其它菌株，该结果为啤酒酵母特异的分子标记奠定了基础。

Comparison of fermentation properties and RAPD analysis of mutants of yeasts applied in beer brewing

In this paper,9 strains of Saccharomyces cerivisiae mutants were appl ied to beer fermentation experiment to compare their fermentation capability,hi gher alcohol yielding capability,diacetyl reduction capability and genetic stab ility.Genomic molecular differences among different strains were also analyzed by random amplified polymorphic DNA(RAPD)method with a selected effective rand om primer.The results indicated that fermentation degree of different yeast str ains varied between 72.3% and 76.8% after 14 d fermentation and YZB was the high est one.The higher alcohols content of Y1110 was lowest among all yeast strains.The diacetyl value of both YZB and Y1110 could be reduced to less than 0.1 mg/L after post fermentation.The genetic stability experiments showed no obvious c hanges in fermentation characteristics between the first and the seventh generat ion.Y1110,YZB and YZD could be distinguished by specific RAPD fingerprint ampl ified with random primer OPG-5.These results established the basis for the spec ific molecular marking of beer yeast at genomic level.