Abstract
BACKGROUND: Dihydroquercetin (DHQ), a powerful bioflavonoid, has a number of health-promoting qualities and shows potential as a treatment for a number of disorders. Dihydroquercetin biosynthesis is a promising solution to meet the rising demand for dihydroquercetin. However, due to the significant accumulation of eriodietyol (ERI), naringenin (NAR), dihydrokaempferol (DHK), and other metabolites, the yield of DHQ biosynthesis is low. As a result, this is the hindrance to the biosynthesis of DHQ. RESULTS: In this study, we proposed several strategies to enhance the product formation and reduce the metabolites in accumulation. The flavonoid 3'-hydroxylase (F3'H) and cytochrome P450 reductase from different species were co-expressed in S. cerevisiae, and the best strain expressing the P450-reductase enzyme complex (SmF3'H/ScCPR) yielded 435.7 ± 7.6 mg/L of ERI from NAR in the deepwell microplate. The product conversion rate was improved further by mutating the predicted potential ubiquitination sites to improve SmF3'H stability, resulting in a 12.8% increase in titre using the mutant SmF3'H (K290R). Besides, different F3Hs from various sources and promoters were tested for the improved DHQ production, with the best strain producing 381.2 ± 10.7 mg/L of DHQ from 1 g/L of NAR, suggesting the temporal regulation the expression of F3H is important for maximization the function of F3'H and F3H. CONCLUSION: This study offers effective strategies for improving DHQ production from NAR and could be used as a reference for related research.