2-60: Enhanced production of 1,2-propanediol Saccharomyces cerevisiae by metabolic engineering and carbon source optimization

1,2-Propanediol, also known as propylene glycol, is a major commodity chemical with world market of $ 123.6 millions/yr. We metabolically engineered S. cerevisiae strain to improve 1,2-propanediol production. When we deleted tpi1(triosephosphate isomerase) gene of S. cerevisiae to increase metabolic flux to DHAP(dihydroxyacetone phosphate) and introduced mgs(methylglyoxal synthase) and gldA(glycerol dehydrogenase) using a multicopy plasmid, 1.11 g/l 1,2-propanediol was achieved with 2%(v/v) ethanol as a major carbon source. When glycerol was used as a sole carbon source under anaerobic condition, much higher 1,2-propanediol productivity was achieved with overexpression of mgs and gldA. The productivity was enhanced when fps1 gene encoding glycerol transporter was overexpressed in S. cerevisiae. As a result, we got 3.23 g/l 1,2-propanediol concentration during 144h flask cultivation with 10%(v/v) glycerol as a carbon source.