摘要
低糖度啤酒又称干啤酒,1987年首先在日本上市,很快流行欧美。干啤酒具有纯正、爽口、低热值等特点,因而口感好又有益于健康,颇受欢迎,加之与普通啤酒相比,干啤酒生产对原料淀粉利用率高,因此干啤酒是我国啤酒工业的发展方向。干啤酒生产要求把发酵度提高到75％以上,关键在于提高麦芽汁中的酵母可发酵糖的比例,现今多采用外加糖化酶或异淀粉酶的工艺来解决。Lancashire和Kim利用基因工程技术已分别把Schwanniomyces occidentalis和S.diastaticus的糖化酶基因引入啤酒酵母,以期用于干啤酒的直接发酵生产。我们已陆续报道黑曲霉糖化酶在实验室酿酒酵母中的表达和分泌,在此基础上又进行了DNA对多倍体的工业酵母的转化研究,本文即报道具有糖化酶功能的啤酒酵母的构建及工程菌的发酵特性。
The brewer's yeast having glucoamylase activity was constructed by integrating glucoamylase cDNA from Asp ergillus niger into the genome of brewer's Yeast B48. The integration was achieved by cotransformation of YEP type plasmid pBEJ16 carrying G418 resistance expression element and YIP type plasmicl pKG1 carrying glucoamylase expression - secretion element and was verified by Southern blot analysis. The engineered yeast was stable. The fermentation test demonstrated that the lower residual dextrin level was obtained compared with control strain B48. Thus the fermentation rate was raised to 80. 5%. No alteration of growth and brewing properties was observed. Beer quality was judged to be good.
出处
《生物工程学报》
CAS
CSCD
北大核心
1996年第4期489-491,共3页
Chinese Journal of Biotechnology
基金
国家"八.五"攻关项目资助课题
关键词
啤酒酵母
构建
发酵特性
糖化酶
Glucoamylase, cotransformation, brewer's yeast
