(671f) De Novo Stereospecific Biosynthesis of 1,2-Propanediol

1,2-propanediol (1,2-PDO) is an industrial chemical with a broad range of applications, such as the production of alkyd and unsaturated polyester resins. It is currently produced as a racemic mixture from nonrenewable petroleum-based feedstocks. We have reported novel artificial pathways for the biosynthesis of 1,2-PDO via lactic acid isomers as the intermediates. The pathway circumvents the cytotoxicity issue caused by methylglyoxal intermediate in the naturally existing pathway and leads to the stereospecific production of 1,2-PDO isomers. In this talk, we will discuss the engineering of the pathway in E. coli host strains for de novo biosynthesis, enzyme directed evolution strategy to improve the kinetic properties of a rate-limiting enzyme, and the application of an alternate catalytic strategy using carboxylic acid reductase.