[关键词]
[摘要]
从上海地区黄酒酿造企业的主发酵液、酒母和酒糟中分离得到4株起酵能力、产酒精能力和发酵性能较好的BR 20、BR 25、BR 26和BR 30菌株。经5.8S rDNA-ITS测序分析,鉴定分离筛选所得的4株菌为酿酒酵母(Saccharomyces cerevisiae)。分析研究4株菌对高浓度乙醇、高糖浓度、高浓度乳酸和高渗透压的耐受性,BR 20和BR 30菌株可耐受18%的酒精,对1.6 mol/L高渗透压有较好的适应性;BR 20与B R 26菌株在高达54 g/L的乳酸下具有较好的生长;BR 30菌株对40%糖浓度表现出最强的耐受能力;最终筛选出抗逆性能较强的BR 20和BR 30菌株。比较研究了BR 20菌株和BR 30菌株的发酵效率,BR 20菌株的底物利用率较BR 30菌株平均高出1.67%,BR 20菌株的乙醇产率较BR 30菌株平均高出5.76%。BR 20和BR 30菌株作为混合发酵菌种用在黄酒生产中可缩短发酵时间、提高原料利用率并且增加出酒率。
[Key word]
[Abstract]
Four strains of yeast, namely BR 20, BR 25, BR 26 and BR 30, with preferable values for initial fermentation capacity, alcohol-producing ability, and fermentation performance were isolated from the main fermentation broth, yeast starter culture as well as from industrial units in the Shanghai area producing yellow rice wine. These four strains were identified as Saccharomyces cerevisiae by 5.8S rDNA-ITS sequence analysis. These four strains were analyzed in terms of tolerance to high concentrations of ethanol, sugar, and lactic acid as well as high osmotic pressure. The results showed that not only could the BR 20 and BR 30 strains withstand 18% alcohol concentration, but they could also adapt to high osmotic pressures of up to 1.6 mol/L. On the other hand, BR 20 and BR 26 stains had preferable growth capacity in the presence of high content of lactic acid, up to 54 g/L, while BR 30 strain showed highest tolerance to sugar, at 40% concentration. Thus, BR 20 and BR 30 strains showed highest resistance to stress and were chosen for further experiments. Comparison of the fermentation efficiency of BR 20 and BR 30 strains showed that the average substrate utilization rate of BR 20 strain was 1.67% higher than that of the BR 30 strain, and the average ethanol yield of BR 20 strain was 6.76% higher than that of the BR 30 strain. Thus, the use of the BR 20 and BR 30 strains as hybrid strains for wine fermentation from yellow rice will reduce fermentation time, improve the utilization of raw materials, and increase alcohol yield.
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[基金项目]
上海市产学研合作年度计划(沪CXY-2013-51);上海市农业科技成果转化资金项目(133919N1000);上海市研究生创新基金项目