摘要
利用PCR的方法从鼠李糖乳杆菌基因组DNA中扩增到D-(+)-乳酸脱氢酶基因(ldhD),并连接到载体pSE380上,构建表达质粒pSE-ldhD,将重组质粒pSE-ldhD转化大肠杆菌BL21(DE3),重组菌株经IPTG诱导表达,SDS-PAGE电泳分析表明ldhD在大肠杆菌中实现了表达,表达产物的分子量约为37kD。同时采用紫外分光光度法测定D-乳酸脱氢酶的酶活,测得重组菌株的D-乳酸脱氢酶活力为5.4U/mL,最适反应温度为35℃,最适pH为5.6。
The gene ldhD encoding D-（＋）-lactate dehydrogenase was amplified from genome DNA of Lactobacillus rhamnosus by PCR.The PCR product was ligated with the expression vector pSE380 after double-digested.A recombinant plasmid pSE-ldhD was constructed and transformed into E.coli BL21（DE3）.The D-（＋）-lactate dehydrogenase activity of recombinant strain was determined with spectrum assay after IPTG induction.SDS-PAGE result showed that the cloned ldhD was expressed in the E.coli,and the relative molecular weight of the expression product was about 37 kD.The activity of D-（＋）-lactate dehydrogenase of recombinant strain was 5.4 U/mL.The optimal temperature and pH were 35℃ and 5.6.
出处
《生物技术通报》
CAS
CSCD
北大核心
2010年第12期196-200,共5页
Biotechnology Bulletin
基金
国家科技支撑计划项目(2007BAD75B06)
广西科学基金项目(桂科攻0782003-4)
