摘要
通过在大肠杆菌(Escherichia coli)中过量表达来自加州月桂(Umbellulana california)的硫酯酶基因BTE,极大地加强了大肠杆菌中碳脂肪酸(MCFAs)的生产。并对MCFAs在大肠杆菌胞内外的分布,以及是否对大肠杆菌细胞膜磷脂组成产生影响等进行了系统的分析。结果发现,产生的MCFAs绝大部分存在于大肠杆菌细胞内,且未对其细胞膜磷脂组成产生明显影响。为了继续提高MCFAs的产量,又进一步对大肠杆菌进行了代谢工程改造,通过结合表达乙酰-CoA羧化酶(ACCase),优化硫酯酶的表达水平等,最终获得了188.9mg/L的总MCFAs产量,并且产生的MCFAs的比例高达85%以上,实现了MCFAs的高特异性生产。
Medium-chain fatty acids （MCFAs） are the major components of medium-chain triglycerides （MCT）, whichplay an important role in the food additive industry. In this study, the production of MCFAs was greatly enhanced byoverexpressed thioesterase gene of Umbellulana california （BTE） in E. coli. In addition, the location of the producedMCFAs and the effect of synthesized MCFAs on the composition of membrane phospholipids were also determined. Theresults indicated that MCFAs were mainly located in E. coli, and their production had little effect on the composition ofmembrane phospholipids. To further improve the production of MCFAs, strategies including co-overexpression of acetyl-CoA carboxylase （ACCase） and the optimization of the expression level of thioesterase BTE were also carried out. Finally,188.9 mg/L MCFAs were achieved, representing a rather high production of MCFAs. Meanwhile, the MCFAs accounted forover 85% of the total free fatty acids, suggesting the high-specificity production of MCFAs.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2013年第21期131-135,共5页
Food Science
基金
国家自然科学基金项目(21106170)
中国科学院知识创新工程重要方向性项目(KSCX2-EW-G-13)
广东省中国科学院全面战略合作项目(2009B091300146)
关键词
中碳脂肪酸
大肠杆菌
硫酯酶
代谢工程
medium-chain fatty acid
Escherichia coli
thioesterase
metabolic engineering
