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 th...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 P tufB , P gmr , P glp1 , and P glp2 in G. oxydans 621H. The results show that the glycerol tolerances of strains overexpressing G lpF were all much better than that of the control strain. The glycerol dehydrogenase gene (G dh) was overexpressed by the promoters P tufB and P gdh , which increased the DHA titer by 12.7% compared with that of the control group. When G lpF 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 di erent degrees, as compared with strains that overexpressed only G dh . This study provides a reference for future research on DHA production.展开更多
In order to investigate the expression of glycerol-3 -phosphate dehydrogenase by GCY1 gene in recombinant Saccharomyces cerevisiae, induction culture of the S. cerevisiaestrain was performed with SD-URA 2% galactose, ...In order to investigate the expression of glycerol-3 -phosphate dehydrogenase by GCY1 gene in recombinant Saccharomyces cerevisiae, induction culture of the S. cerevisiaestrain was performed with SD-URA 2% galactose, 3 × YP ＋ 6% glucose, SC-URA 2% galactose, and SC-URA 2% galactose ＋ 5% NaCI glyeerol-3-phosphate dehydregenase, the cultured S. cerevisiaewas comminuted followed by full-automatic high-speed purification, and SDS-PAGE gel electrophoresis was performed for molecular weight of the GST fusion protein. The results showed that after shaking culture of the S. cerevisiae containing GCY1 at 25 ℃, the OD values of its 3 × YP ＋ 6% glucose culture and SC-URA 2% galaetose ＋ 5% NaC1 culture were 8.75 and 7.35, respectively. It was shown by purification with a Profinia low-pressure liquid chromatograph that only the S. cerevisiae cultured in SC-URA 2% galactose ＋ 5% NaC1 medium expressed glycerel-3-phosphate de- hydrogenase, the molecular weight of which was detected as 65 ku by SDS-PAGE gel electrophoresis.展开更多
基金supported by the Major Research Plan of Tianjin (16YFXTSF00460)
文摘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 P tufB , P gmr , P glp1 , and P glp2 in G. oxydans 621H. The results show that the glycerol tolerances of strains overexpressing G lpF were all much better than that of the control strain. The glycerol dehydrogenase gene (G dh) was overexpressed by the promoters P tufB and P gdh , which increased the DHA titer by 12.7% compared with that of the control group. When G lpF 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 di erent degrees, as compared with strains that overexpressed only G dh . This study provides a reference for future research on DHA production.
基金Supported by Social Service Project of New Countryside Development Research Institute of Yangtze University(201411)
文摘In order to investigate the expression of glycerol-3 -phosphate dehydrogenase by GCY1 gene in recombinant Saccharomyces cerevisiae, induction culture of the S. cerevisiaestrain was performed with SD-URA 2% galactose, 3 × YP ＋ 6% glucose, SC-URA 2% galactose, and SC-URA 2% galactose ＋ 5% NaCI glyeerol-3-phosphate dehydregenase, the cultured S. cerevisiaewas comminuted followed by full-automatic high-speed purification, and SDS-PAGE gel electrophoresis was performed for molecular weight of the GST fusion protein. The results showed that after shaking culture of the S. cerevisiae containing GCY1 at 25 ℃, the OD values of its 3 × YP ＋ 6% glucose culture and SC-URA 2% galaetose ＋ 5% NaC1 culture were 8.75 and 7.35, respectively. It was shown by purification with a Profinia low-pressure liquid chromatograph that only the S. cerevisiae cultured in SC-URA 2% galactose ＋ 5% NaC1 medium expressed glycerel-3-phosphate de- hydrogenase, the molecular weight of which was detected as 65 ku by SDS-PAGE gel electrophoresis.
