Isolation and Characterization of Glucosinolate-Hydrolysis Enterococcus gallinarum HG001 and Escherichia coli HG002 from C57BL/6 Mouse Microbiota

Glucosinolate (GSL) is an important active substance in broccoli and can be hydrolyzed to isothiocyanates (ITCs) by endogenous myrosinase. The ITCs are well-known chemopreventive agents that have received significant attention across the nutrition and pharmaceutical industries due to their anticancer properties. Myrosinase activity decreases during the cooking of broccoli, thus it is essential to study the microbiota involved in GSL hydrolysis to maximize their health benefits. In this study, two strains ( Enterococcus gallinarum HG001 and Escherichia coli HG002) isolated from the gut microbiota of C57BL/6 mice were identified through 16 S rRNA gene sequence and characteristic analyses. The maximum GSL hydrolysis activity of 12 strains was observed using the cyclocondensation method. Their growth curves, GSL-hydrolysis curves, ITC generation curves and GSL-hydrolysis products were analyzed. The En. gallisepticum HG001 hydrolyzed GSL to a greater level than the E. coli HG002. It was observed that they could hydrolyze GSL to produce erucin nitrile and 4-methylsulfanylbutyro nitrile through gas chromatography-mass spectrometer analysis.