Research of 1,3-Dihydroxyacetone Production by Overexpressing Glycerol Transporter and Glycerol Dehydrogenase

Abstract

1,3-Dihydroxyacetone (DHA), a natural ketose, is widely used in the chemical, cosmetic, and pharmaceutical industries. The current method for DHA production is Gluconobacter oxydans (G. oxydans) fermentation, but the high concentration of glycerol in the fermentation broth inhibits cells growth. To overcome this obstacle, in this study, we overexpressed the glycerol transporter (GlpFp) by the use of promoters PtufB, Pgmr, Pglp1, and Pglp2 in G. oxydans 621H. The results show that the glycerol tolerances of strains overexpressing GlpF were all much better than that of the control strain. The glycerol dehydrogenase gene (Gdh) was overexpressed by the promoters PtufB and Pgdh, which increased the DHA titer by 12.7% compared with that of the control group. When GlpF and Gdh genes were co-overexpressed in G. oxydans 621H, the OD600 value of the engineered strains all increased, but the DHA titers decreased in different degrees, as compared with strains that overexpressed only Gdh. This study provides a reference for future research on DHA production.