P36: Microbial bioconversion of liquiritigenin by mixed-culture of Laetiporus sulphureus CS0218 and Glycyrrhiza uralensis

The bioactive flavonoid, liquiritigenin which is an aglycone of liquiritin could absorb much faster and enhance their functions than their glucosides in humans, while the glucosides do not completely absorb on intestinal epithelial cells. Here, we demonstrate a simple microbial bioconversion for the production of liquiritigenin which utilized Glycyrrhiza uralensis extracts as co-substrate fermented with the basidomycete Laetiporus sulphureus CS0218. We started with submerged culture of L. sulphureus CS0218 in a shake flask and using this technique we investigated mycelial growth, exo-polysaccharide concentration and culture broth rheology. When fermented with L. sulphureus CS0218, three carbohydrate degrading enzymes were measured; however, alpha-glucosidase seems to play a major role to convert liquiritin (glucoside form) into liquiritigenin (aglycone form) from G. uralensis extracts, up to 67.44% under the optimal bioconversion conditions. The partially isolated liquiritigenin was tested its biological activities. Interestingly, they could activate SIRT1, human deacetylase which is a member of sirtuin family on ageing. These findings indicate that it would be beneficial to produce flavonoid algycones for pharmaceutical, cosmetic and food industries.