Evolution-aided enhancement of β-glucosidase activity for improved conversion of isoflavone glucosides to aglycones by Lactobacillus gasseri.

Isoflavones, known for their estrogen-like structures, are bioactive compounds with various health benefits, particularly for menopausal women. Conversion of isoflavone glucosides into their aglycone forms is critical for enhancing their bioavailability and biological activity. Here, adaptive laboratory evolution (ALE) was employed to enhance the β-glucosidase activity of Lactobacillus gasseri (LGA1) for efficient bioconversion of isoflavone glucosides into their aglycone forms in soybean germ extract. The evolved 20-5 strain was developed through ALE and demonstrated a significant increase in the production of isoflavone aglycones, particularly daidzein, which exhibited higher bioavailability and superior biological activity. Whole-genome resequencing and comparative genomic analysis of the parental and evolved 20-5 strains revealed genetic mutations possibly responsible for enhancing daidzein production. This study highlights the potential of ALE as a tool for optimizing probiotic strains, contributing to the development of functional foods enriched with bioactive compounds and advancing their biotechnological applications.