A Biotransformation Process for Production of Genistein from Sophoricoside by a Strain of Rhizopus oryza

Jianfeng Mei,Yu Yi,Jianghua Liu,Guoqing Ying,Yanlu Zhang,Xiang Chen

doi:10.1038/s41598-019-42996-z

Abstract

Genistein is known to have multiple biological activities and has great potential for use as a preventative medicine and in disease treatment. Genistein can be extracted from plants, but also can be obtained from its glycoside form, sophoricoside, which is more abundant in some plants. Biotransformation by unpurified microbial enzymes has the advantage of low cost and is a preferred method for production of natural compounds. This study isolated a strain of Rhizopus oryzae that could produce β-glucosidase, which efficiently hydrolyzes sophoricoside into genistein, from an enrichment culture of the dried fruits of Sophora japonica. After the composition of enzyme-producing medium and biotransformation conditions were optimized, a genistein yield of 85.6% was obtained after 24 h in a shake-flask biotransformation at pH 7.0 using an initial substrate concentration of 1 g/L. The developed process provides an alternative method for production of genistein, and would be suitable for scale-up production in the pharmaceutical industry.

Highlights

In this study, a strain of Rhizopus oryzae was isolated from an enrichment culture of Sophorae Fructus to produce β-glucosidase, which was used for biotransformation of sophoricoside into genistein
Among ten fungi strains that were isolated from the enrichment culture of Sophorae Fructus, only one strain, LJH-3, produced enzymes that converted sophoricoside into genistein with a yield over 20%
We concluded that strain LJH-3 secretes β-glycosidase, which trimmed the glycosidic bond of sophoricoside to produce genistein

Summary

Introduction

A strain of Rhizopus oryzae was isolated from an enrichment culture of Sophorae Fructus to produce β-glucosidase, which was used for biotransformation of sophoricoside into genistein. The composition of the enzyme-producing medium was optimized for Rhizopus oryzae to produce β-glucosidase, and the enzymatic hydrolysis conditions were optimized to improve the yield of genistein. This biotransformation process has great potential for use in the pharmaceutical industry

Methods

Results

Conclusion