摘要
采用基因工程方法和进化工程相结合的策略对酿酒酵母进行遗传改造,获得高效表达L-乳酸的酿酒酵母适应工程菌。以酵母丙酮酸脱羧酶基因1为同源序列构建乳酸脱氢酶编码基因整合片段,并与酵母自主表达质粒pUT332共转化酿酒酵母菌,筛选具有乳酸脱氢酶活性的转化子。再通过进一步适应进化筛选高产乳酸的酿酒酵母工程菌。结果表明,工程菌的培养介质组成(g/L)为糖蜜总糖120、玉米黄浆水1 000、K2HPO46,起始pH 5.0;发酵条件为发酵时间4 d,接种量10%,搅拌速度650 r/min,通气量1.5 L/min,发酵温度30℃。
An engineered Saccharomyces cerevise strain was constructed by genetic engineering and evolution method. First, construct the integrated chimeric fragment of lactic dehydrogenase （LDH） using yeast pyruvate decarboxylase 1 gene as the homologous integrative site,then co-transform the fragment into the S. cerevise with yeast episomal plasmid pUT332 and select the transformants with LDH activity. Further screen was carried out by adaptive evolution method and obtain the interest strain which grows quickly and secrets L-lactic acid efficiently. The optimized culture media composition（g/L） was molasses 120, corn paste waste water 1 000, K2HPO4 6, pH 5.0. The optimized fermentation parameters are as follow, fermentation time 4 d,inoculating rate 10 %, stirring rate 650 r/min, aeration rate 1.5 L/min,fermentation temperature 30 ℃.
出处
《食品研究与开发》
CAS
北大核心
2012年第7期164-168,共5页
Food Research and Development
基金
河北省引进留学人员资助项目(2011226)
河北省社会科学发展研究课题(201103161)
关键词
L-乳酸
适应进化
遗传改造
农副产品
环境友好
L-lactic acid
adaptive evolution
genetic modification
agricultural by-products
environment-friendly
