One-pot green and sustainable process for the biotransformation of sophoricoside to genistein from Fructus Sophorae with magnetic cellulose spheres immobilized Aspergillus oryzae on cellulose using deep eutectic solvent assisted.

Abstract

This study introduces a green, sustainable, and efficient approach for biotransforming sophoricoside into genistein from Fructus Sophorae using Aspergillus oryzae by removal of one molecule of glucose by β-glucosidase, an edible microorganism immobilized on magnetic cellulose and treated with deep eutectic solvents (DES). The goal was to enhance the biotransformation ratio by optimizing reaction conditions and selecting the most suitable DES. Various DESs, including natural deep eutectic solvents (NADES), were assessed for their ability to improve catalytic performance. Among them, the NADES system comprising choline chloride (CHCL) and glycerol (G) exhibited the highest catalytic efficiency (32.19 mg/g) under optimal conditions: temperature 33 °C, time 65 hours, pH 5.5, and a liquid-to-solid ratio of 45:1 (mL/g). This yield was 10.60 times greater than the genistein yield from untreated F. Sophorae. This combination notably increased cell membrane permeability, aiding the bioconversion process. The cellulose immobilization technique provided a stable and reusable microreactor and maintained microbial activity (80.37%) over 10 cycles. These findings validate the bioconversion method as a promising and sustainable strategy for genistein production from plant-derived sophoricoside, with potential applications in pharmaceutical and nutraceutical industries.