Enzyme systems involved in glucosinolate metabolism in Companilactobacillus farciminis KB1089

Abstract

Cruciferous vegetables are rich sources of glucosinolates (GSLs). GSLs are degraded into isothiocyanates, which are potent anticarcinogens, by human gut bacteria. However, the mechanisms and enzymes involved in gut bacteria-mediated GSL metabolism are currently unclear. This study aimed to elucidate the enzymes involved in GSL metabolism in lactic acid bacteria, a type of gut bacteria. Companilactobacillus farciminis KB1089 was selected as a lactic acid bacteria strain model that metabolizes sinigrin, which is a GSL, into allylisothiocyanate. The sinigrin-metabolizing activity of this strain is induced under glucose-absent and sinigrin-present conditions. A quantitative comparative proteomic analysis was conducted and a total of 20 proteins that were specifically expressed in the induced cells were identified. Three candidate proteins, β-glucoside-specific IIB, IIC, IIA phosphotransferase system (PTS) components (CfPttS), 6-phospho-β-glucosidase (CfPbgS) and a hypothetical protein (CfNukS), were suspected to be involved in sinigrin-metabolism and were thus investigated further. We hypothesize a pathway for sinigrin degradation, wherein sinigrin is taken up and phosphorylated by CfPttS, and subsequently, the phosphorylated entity is degraded by CfPbgS. As expression of both pttS and pbgS genes clearly gave Escherichia coli host strain sinigrin converting activity, these genes were suggested to be responsible for sinigrin degradation. Furthermore, heterologous expression analysis using Lactococcus lactis suggested that CfPttS was important for sinigrin degradation and CfPbgS degraded phosphorylated sinigrin.

Deciphering the Myrosinase-like Activity of Lactiplantibacillus plantarum WCFS1 among GH1 Family Glycoside Hydrolases

“…This hypothesis is supported by the fact that Lp_3132, together with Lp_3133, a β-glucoside-specific IIB, IIC, and IIA phosphotransferase system (PTS) component, is the homolog of pbgS and pttS from C. farciminis KB1089, the enzyme systems involved in glucosinolate metabolism in that bacterium. , …”

“…This hypothesis is supported by the fact that Lp_3132, together with Lp_3133, a β-glucoside-specific IIB, IIC, and IIA phosphotransferase system (PTS) component, is the homolog of pbgS and pttS from C. farciminis KB1089, the enzyme systems involved in glucosinolate metabolism in that bacterium. 18,24 Although Lp_3132 exhibited the highest apparent catalytic efficiency as 6-phospho-β-thioglucosidase among GH1 L. plantarum proteins, this compound was also a substrate for additional seven GH1 proteins. The redundancy of 6-phosphoβ-glucosidase proteins putatively involved in glucosinolate metabolism has been previously described in E. coli O 157:H7.…”

“…23 In the putative myrosinase-like pathway, glucosinolates may undergo previous phosphorylation on the sugar residue, as has been recently demonstrated in Companilactobacillus farciminis KB1089. 18 All glucosinolate structures are based on a β-S-glucopyrano unit anomerically connected to an O-sulfated thiohydroximate function. 3 In nature, three types of glycosidic linkages occur, the O-, N-, and S-glycosidic linkage.…”

Microorganisms—An Effective Tool to Intensify the Utilization of Sulforaphane

“…However, the mechanisms by which intestinal myrosinase produces SFN remain unclear. Watanabe et al, studying LAB as research objects, found that intestinal myrosinase may be involved in the metabolism of glucoraphanin through the β-glucoside-specific IIB, IIC, and IIA phosphotransferase system components ( Figure 1 ) [ 72 ]. With the intestinal myrosinase synthesis mechanisms becoming clear, researchers further investigated the myrosinase synthesis capabilities of microorganisms to identify the types of microorganisms that synthesize myrosinase.…”

A new source of bacterial myrosinase isolated from endophytic Bacillus sp. NGB-B10, and its relevance in biological control activity

“…However, myrosinase has been also identified in insects (Jones et al 2001 ; Pontoppidan et al 2001 ), fungi (Rakariyatham et al 2005 ; Szucs et al 2018 ; Abdel-Fatah et al 2021 ), and human gut microbiota (Liou et al 2020 ; Sikorska-Zimny and Beneduce 2021 ). Many reports have described the isolation and characterization of myrosinase-producing strains belonging to diverse bacterial genera such as Bacillus (El-Shora et al 2016 ; Luang-In et al 2018 ), Companilactobacillus (Watanabe et al 2021 ) Citrobacter (Albaser et al 2016 ; Cebeci et al 2022 ), Enterobacter (Tani et al 1974 ; Wassermann et al 2017 ; Luang-In et al 2018 ), Enterococcus (Luang-In et al 2016 , 2018 ) , Lactobacillus (Palop et al 1995 ; Luang-In et al 2014 , 2016 ), Lactococcus (Mullaney et al 2013 ; Luang-In et al 2018 ), and Leclercia (Tie et al 2021 ) which are capable of in-vitro metabolism of GLs. Previous studies reported that the enzyme 6-phospho-β-glucosidase, encoded by the genes bglA , ascB , and chbF , is associated with myrosinase-like activity in bacteria such as Escherichia coli strain O157:H7 (Cordeiro et al 2015 ) and Enterobacter cloacae strain KS50 (Wassermann et al 2017 ) .…”