Efficient de novo synthesis of resveratrol by metabolically engineered Escherichia coli

Resveratrol has been the subject of numerous scientific investigations due to its health-promoting activities against a variety of diseases. However， developing feasible and efficient microbial processes remains challenging owing to the requirement of supplementing expensive phenylpropanoic precursors. Here， various metabolic engineering strategies were developed for efficient de novo biosynthesis of resveratrol. A recombinant malonate assimilation pathway from Rhizobium trifolii was introduced to increase the supply of the key precursor malonyl-CoA and simultaneously， the clustered regularly interspaced short palindromic repeats interference system was explored to down-regulate fatty acid biosynthesis pathway to inactivate the malonyl-CoA consumption pathway. Down-regulation of fabD， fabH， fabB， fabF， fabI increased resveratrol production by 80.2， 195.6， 170.3， 216.5 and 123.7%， respectively. Furthermore， the combined effect of these genetic perturbations was investigated， which increased the resveratrol titer to 188.1 mg/L. Moreover， the efficiency of this synthetic pathway was improved by optimizing the expression level of the rate-limiting enzyme TAL based on reducing mRNA structure of 5' region. This further increased the final resveratrol titer to 304.5 mg/L. The study described here paves the way to the development of a simple and economical process for microbial production of resveratrol.