摘要
以发酵度较高的非絮凝性的啤酒酵母菌株X6和发酵度较低、絮凝性较强的啤酒酵母菌株N1为亲本进行原生质体融合。用亚硝酸诱变原养型的菌株X6，经筛选得到一株需酪素水解物的营养缺陷型菌株X6～20。采用正交试验法分别优化菌株X6-20和N1的原生质体形成和再生的条件。用X6-20菌株的原生质体作为受体和热灭活的N1菌株原生质体作为供体进行融合。融合株经三角瓶发酵筛选，得到一株较优良的融合株GR5该融合株的絮凝性较强（本斯值为2．7），以12°Bx麦芽汁为培养基，用500L的发酵罐在12℃下发酵，发酵至第8d菌株GR的发酵度为69．2％，发酵液中的双乙酰含量为0．0498mg/L、乙醛含量为6．34mg／L，总高级醇含量为74．4mg／L。融合株GR5具有双亲的优点，发酵的啤酒风味较好，是一株具有工业应用前景的啤酒酿造酵母菌株。
Saccharomyces cerevisiae X6 and N1 strains were used as the parent strains for protoplast fusion. The strain X6 was a non-flocculence strain with higher fermentation degree and the strain N1 was a strain with lower fermentation degree and stronger flocculence. The auxotrophic mutant X6-20 required casein hydrolysate was derived from the prototrophic strain X6 by treatment of nitrous acid （HNO2） and nutritional identification. The formation and regeneration conditions of strain X6-20 and N1 protoplast were optimized by orthogonal test method. The protoplast fusants were constructed with auxotrophic mutant X6-20 protoplasts for receptors and heat-inactivated strain N1 protoplasts for suppliers. The fusants obtained were fermented and selected. As a result a fine fusant spain GR5 was obtained. The flocculence of fusant strain GR5 was stronger with 2.7 mL of burns value. The oontent of diacetyl, acetaldehyde, total higher alcohols in the fermented liquid were 0.0498 mg/L, 6.34 mg/L, 74.4 mg/L, respectively, and the fermentation degree was 69.2 % in 500 L fermenter using 12°Bx wort as the medimum at 12℃ for 8 days. The sersory evaluation of the beer produced by the fusant strain GR5 was nice. The results showed that the fusant strain GR5 with the fine properties from its parent strains and well applied prospect in the beer brewing.
出处
《工业微生物》
CAS
CSCD
北大核心
2006年第1期34-37,42,共5页
Industrial Microbiology
关键词
啤酒酵母
原生质体融合
絮凝性
发酵度
正交试验
brewer＇ s yeast
protoplast fusion
flocculence
fermentation degree
orthogonal test
