Engineering of glycerol utilization pathway for ethanol production by Saccharomyces cerevisiae.

Saccharomyces cerevisiae was metabolically engineered to improve ethanol production from glycerol. High rates of glycerol utilization were achieved by simultaneous overexpression of glycerol dehydrogenase (Gcy) and dihydroxyacetone kinase (Dak), which are the enzymes responsible for the conversion of glycerol to glycolytic intermediate dihydroxyacetone phosphate. As a result, ethanol production in YPH499 (pGcyaDak) was about 2.4-fold higher than wild strain. We have also successfully expressed a glycerol uptake protein (Gup1). The overall ethanol production in strain YPH499 (pGcyaDak, pGupCas) was 3.4-fold more than in wild strain, with about 2.4gL(-1) ethanol produced. These experimental results confirmed our metabolic pathway strategies which improve the production of ethanol.