Recombinant Lactobacilli for Ethanol Production

Abstract:

Recombinant plasmids pHY-PA, pBBR-PA were constructed in which genes pdc and adhB were placed under the control of tac promoter, respectively, and had successfully expressed in Escherichia coli. Then these recombinant plasmids were electroporated into Lactobacillus strains for ethanol production. Preliminary ethanol fermentation using these Lactobacillus strains and their recombinants was carried out using 42℃ as fermentation temperature. The results indicated that introducing pdc and adhB, ethanologenic pathway was successfully constructed in L.plantanum CICIM B0080. 0.4% (V/V) ethanol was detected at the end of fermentation with 6.7% glucose, and that is 67-fold as the wild-type B0080. Two-fold of ethanol production was detected in L.amylovorus B0112 (pHY-PA) and L.acidophilus B0068 (pBBR-PA). Introducing both pdc and adhB, and meanwhile knock-outing the lactate dehydrogrnase gene may better convert carbon flux to ethanologenic direction.