Biobutanol Production In Recombinant Escherichia Coli BL21

In this study, Escherichia coli BL21 was engineered for butanol production.  The mutant E. coli BM322 was constructed by disrupting phosphotransacetylase (pta), lactate dehydrogenase A (ldhA), bifunctional acetaldehyde/ethanol dehydrogenase (adhE_B), fumarate reductase (frdBC), and pyruvate oxidase B (poxB) genes.  Additionally, the transcriptional regulator FNR protein gene was also deleted.  The recombinant plasmid pBUOH was constructed by cloning the key enzyme coding genes that are involved in the butanol production pathway in Clostridium acetobutylicum.  These genes include: thiolase (thl), 3-hydroxybutyryl-CoA dehydrogenase (hbd), crotonase (crt), butyryl-CoA dehydrogenase (bcd), electron transfer flavoprotein (etfAB), and the bifunctional butyraldehyde/butanol dehydrogenase (adhE_C).  The recombinant E. coli BM322/pBUOH produced 1.2 g/L butanol with 10.2 g/L lactate as a by-product for 60 h.