Engineering Saccharomyces cerevisiae with the deletion of endogenous glucosidases for the production of flavonoid glucosides

摘要: Glycosylation of flavonoids is a promising approach to improve the pharmacokinetic properties and biological activities flavonoids. Recently, many efforts such as enzymatic biocatalysis engineered Escherichia coli biotransformation have increased production flavonoid glucosides. However, low yield glucosides can not meet increasing demand for human medical dietary needs. Saccharomyces cerevisiae generally regarded safe (GRAS) organism that has several attractive characteristics metabolic engineering platform endogenous glucosidases S. whole-cell biocatalyst reversibly hydrolyse glucosidic bond hinder biosynthesis desired products. In this study, model flavonoid, scutellarein, was used exploit how enhance in cerevisiae. To produce glucosides, three glucosyltransferases (SbGTs) from Scutellaria baicalensis Georgi were successfully expressed E. coli, their biochemical characterizations identified. addition, synthesize cerevisiae, SbGT34 selected constructing yeast. Three glucosidase genes (EXG1, SPR1, YIR007W) knocked out using homologous integration, EXG1 gene determined be decisive process hydrolysing further potential glycosylation activity two encoding phosphoglucomutase UTP-glucose-1-phosphate uridylyltransferase involved synthetic system uridine diphosphate glucose over-expressed Consequently, approximately 4.8 g (1.2 g/L) scutellarein 7-O-glucoside (S7G) produced 4 L medium after 54 h incubation 10-L fermenter while being supplied with ~3.5 g scutellarein. The yeast harbouring SbGT with deletion more than strains without glucosidases. This could modify wide range valued plant secondary metabolites explore functions biocatalyst.