Efficient biosynthesis of three rare formononetin derivatives by newly discovered Bacillus velezensis LQ5

Formononetin is a natural flavonoid existing widely in plants with many pharmacological effects. However, its application is limited by structure, poor water solubility and low bioavailability. In this study, Bacillus velezensis LQ5 was isolated from the inter-root soil of Glycyrrhiza uralensis Fisch for the first time and formononetin was firstly structurally modified by whole-cell catalysis of LQ5 to obtain formononetin-7-O-β-D-glucoside (FG), formononetin-7-O-β-(6''-O-succinyl)-D-glucoside (FGS) and formononetin-7-O-phosphate (FP). The selective preparation of the three products was achieved by adjusting the content of yeast extract, type and content of sugars, metal ions, pH and ATP content. The result confirmed that FP had the ideal drug-likeness properties and showed a greater ability to reduce intracellular reactive oxygen species levels and regulate oxidative enzymes. This work successfully established a biotransformation method for the efficient transformation of formononetin to produce high-value formononetin derivatives.