Production Of Resveratrol In Engineered Escherichia Coli

Resveratrol(Res)is a kind of flavonoid polyphenol compounds,which widely exists in giant knotweed,grapes and other plants.In recent years,the researchers found that resveratrol has many beneficial effects on humans,such as anti-cancer,anti-oxidation,anti-aging and prevention of cardiovascular disease,etc.Thus,resveratrol becomes one of the most promising natural active substances.It not only has the potential to become a cancer drug,and also widely used in health care products and cosmetics.However,resveratrol content in plants is low.In addition,it is too hard to be extracted from plants with high purity,which can’t meet the demand of the market.Therefore,development of a new method for producing resveratrol is particularly important.In this research we used Escherichia coli to construct engineering bacteria which can produce resveratrol on the basis of genetic engineering technology.Through fermenting engineering bacterium,4-coumaric acid was been transformed to resveratrol and achieved a certain yield.,which laid the foundation for the future industrialization.Microbial synthesis method is not only simple,targeted,and can protect the plant resources at the same time.In this paper,two key enzyme genes 4cl and sts that are used to synthetize resveratrol were got from arabidopsis thaliana and grapes.The protein encoded by 4cl is 4-coumaric acid:Co A ligase,which can catalyze 4-coumaric acid to 4-coumaroyl CoA;The protein encoded by sts is stilbene synthase,which can catalyze one molecule 4-coumaroyl CoA and 3 molecules malonyl-CoA to form resveratrol.We constructed three recombinant plasmids.The first is a common expression system called pETduet-sts-4cl,which can express 4cl and sts,respectively;the second is the fusion expression system called pETduet-sts::4cl,which can express the fusion protein STS::4CL;the third is the fusion expression system called pETduet-4cl::sts and it can express the fusion protein 4CL::STS.Then,the three recombinant plasmids were transfered into E.coli expression strain BL21 respectively and obtained the engineering bacteria which can produce resveratrol.After adding 1 mM 4-coumaric acid for fermentation,resveratrol production were 12.0 mg/L,61.1 mg/L and 24.2 mg/L respectively by HPLC detection.Considering lack of malonyl CoA in the cell,malonyl CoA synthetase gene aae from arabidopsis was cloned into the resveratrol engineering bacteria for the first time in this study.After adding 4-coumaric acid and malonic acid for fermentation,the resveratrol production in the recombinant engineering bacteria BL21 is up to 80.8 mg/L.