知识与财富的链接
利用PCR方法从运动发酵单孢菌染色体DNA扩增出乙醇合成途径的关键酶基因pdc、adhB,分别用tac启动子控制表达,构建了可以在Escherichia coli JM109中表达的重组质粒pKK-PA、pEtac-PA.初步的乙醇发酵结果表明,在E.coli中只引入adhB基因不能拓宽其中的产乙醇途径,引入pdc基因可以与宿主自身的ADH酶协同作用,使碳流有效导向产乙醇方向.同时引入pdc、adhB基因可以在宿主E.coli中成功建立产乙醇途径.
Genes pdc and adhB encoding essential ethanologenic enzymes in Zymomonas mobilis were amplified by using PCR technique. Recombinant plasmids pKK-PA, pEtac-PA were constructed in which genes pdc and adhB were placed under the control of tac promoter, respectively. Preliminary ethanol fermentation using the E. coli JM109 and its recombinants was carried out. The results indicated that introduction of adhB alone could not widen ethanologenic pathway in E. coli JM109.Introduction of pdc converted carbon flux to ethanologenic direction which was presumed to result from combined activities of pyruvate decarbonase from Z. mobilis and the native E. coli alcohol dehydrogenase. Introducing both pdc and adhB, ethanologenic pathway was successfully constructed in E. coli.
