酿酒酵母gpd1和hor2基因在大肠杆菌中的共表达

利用途径工程的方法,在大肠杆菌中构建一条新的产甘油的代谢途径。从酿酒酵母(Saccharomyces cerevisiae)克隆3-磷酸甘油脱氢酶基因(gpd1)和3-磷酸甘油酯酶基因(hor2),并将两个基因串连到启动子trc的下游,构建由trc启动子控制的能高效表达的多顺反子重组质粒pSE-gpd1-hor2,将重组质粒导入大肠杆菌BL21菌株中,构建得到的重组菌株GxB-gh能将葡萄糖转化为甘油。结果表明重组菌株GxB-gh以葡萄糖为底物进行发酵,甘油产量为46．67g／L,葡萄糖的转化率为42.87％。这为利用工程菌绿色生产甘油进行了前期的探索,也为进一步构建能生产1,3-丙二醇的工程菌打下了良好的基础。

Co-expression of gpd1 and hor2 from Saccharomyces cerevisiae in Escherichia coli

Based on the principle of the pathway engineering, a novel pathway of producing glycerol was built in E. coli. The gpd1 gene encoding glycerol 3-phosphate dehydrogenase and the hor2 gene encoding glycerol 3-phosphatase were cloned from Saccharomyces cerevisiae, respectively. The two genes were inserted into expression vector pSE380 together. A recombinant plasmid pSE-gpd1-hor2 containing polycistron was constructed under the control of the strong trc promoter. Then it was transformed into E. coli BL21. The result showed the recombinant microorganism GxB-gh could convert glucose to glycerol directly. And the recombinant microorganism GxB-gh was incubated to produce glycerol from D-glucose in the fermentor. The maximal concentration of glycerol was 46.67g/L at 26h. Conversion rate of glucose was 42.87%. The study is about "green" producing glycerol by recombinant microorganism and is also useful for further working in recombining microorganism of producing 1,3-propanediol.