摘要
以可利用蔗糖的Escherichia coli W为出发菌株,敲除产生副产物的相关基因(adhE,frdBC,pta,pflB,aldA),为促进蔗糖利用,还敲除蔗糖启动子的抑制基因(cscR),构建了D-乳酸工程菌WD 206.结果表明,该菌经72h发酵可有效将100g/L蔗糖转化生成88.15g/L乳酸,产率为84%,占代谢产物的99.5%,D-乳酸的光学纯度达99.8%.
By genetic engineering, the competing fermentative pathway genes （adhE, frdBC, pta, pflB, aldA） and the repressor gene （cscR） of the sucrose operon were deleted from Escherichia coli W, a sucrose positive strain. The constructed strain, WD 206, efficiently utilized 100 g/L sucrose for production of 88.15 g/L lactic acid in 72 h in the media of mineral salts, with extreme low levels of by-products. The product yield of lactic acid was 84% and D-lactic acid optical purity 99%. These results demonstrate that the strain has great potential for production of D-lactic acid with high optical purity by using inexpensive substrates such as sugar cane and/or beet molasses, which are primarily composed of sucrose.
出处
《过程工程学报》
CAS
CSCD
北大核心
2012年第6期989-995,共7页
The Chinese Journal of Process Engineering
基金
国家自然科学基金资助项目(编号:NSFC31070094)
湖北省自然科学基金资助项目(编号:2011CDB076)
湖北省楚天学者专项基金资助项目
关键词
D-乳酸
大肠杆菌
基因工程
蔗糖发酵
D-lactic acid
Escherichia coli
genetic engineering
sucrose fermentation
