Butanol Production From Glycerol By Recombinant Escherichia Coli

Butanol has a lot of application in chemical, energy and food industry, with the continuous shortage of oil resources, biofuels attract wide concerns, as a kind of new biofuel.it is an ideal alternative fuel of oil. Compared with glucose, glycerol has a high deoxidation degree, it is very profitable using glycerol to synthesize butanol.The thil, adhE2and BCS operon gene were amplified by PCR technology with C. acetobutylicum ATCC824genome as a template, and ligated to expression vector pETDuet-1and pACYCDuet-1, the recombinant plasmids pA and pBT were transformed into E. coli MG1655(DE3),the recombinant E. coli can produce19.0mg/L butanol under micro-aerobic condition in TB medium.in order to improve the butanol production, glycerol transport protein gene GlpF was cloned to expression vector pETDuet-1,the recombinant plasmids pAG and pBT was transformed into E. coli MG1655(DE3). the recombinant E. coli can produce33.5mg/L butanol under micro-aerobic condition in TB medium.There are many byproducts produced during the fermentation,such as ethanol. succinic acid, lactic acid, to further improve the butanol production,the competing pathway gene ldha, adhe, frdBC were deleted,and the recombinant E. coli can produce97.9mg/L butanol under micro-aerobic condition in TB medium.Studies have shown that the transferring pathway requires4mol of NADH to produce1mol of butanol,to research the NADH affection, so we introduced a NADH regeneration system to the E.coli by introducing a FDH1gene from Candida boidinii,improved butanol titers were achieved to154.5mg/L in lab-scale shake-flask experiments.However, the E.coli gene FDHF was deleted, the butanol production was reduced.