Genes encoding bile salt hydrolase differentially affect adhesion of <i>Lactiplantibacillus plantarum</i><scp>AR113</scp>

Abstract

Abstract BACKGROUND Adhesion is considered important for Lactiplantibacillus to persist in the human gut and for it to exert probiotic effects. Lactiplantibacillus plantarum contains a considerable number and variety of genes encoding bile salt hydrolases ( bsh ), but their effects on microbial adhesion remain poorly understood. To clarify the effects of four bsh on adhesion, we tried to knock out bsh ( Δbsh ) of L. plantarum AR113 using the CRISPR‐Cas9 method, and compared the growth, auto‐aggregation (R AA ), co‐aggregation (R CA ), surface hydrophobicity (A HC ) of AR113 wild‐type and Δbsh strains and their adhesion abilities to HT29 cells. RESULTS We first obtained the AR113 Δbsh 1,3,2,4 strain with four bsh knocked out. Their growth was significantly slower than the wild‐type strain cultured in De Man, Rogosa, and Sharpe medium (MRS) with 3.0 g L −1 glyco‐ or tauro‐conjugated bile acid. Bsh had no significant effect on the growth of ten strains cultured in MRS, but Δbsh 1 inhibited their growth when cultured in MRS containing 3.0 g L −1 sodium glycocholate, whereas Δbsh 4 instead promoted their growth in MRS with 3.0 g L −1 sodium glycocholate and sodium taurocholate. R CA and R AA were linearly positive for all strains except AR113 Δbsh 2,4, and A HC and R AA were negatively correlated for most strains excluding AR113 Δbsh 2, with R AA = 6.38–25.05%, R CA = 5.17–9.22%, and A CH = 3.22–47.71%. The adhesion ability of ten strains cultured in MRS was higher than that of strains cultured in MRS with 3.0 g L −1 bovine bile, and it was related to bsh 2. CONCLUSION Bsh differentially affected the adhesion of AR113 series strains. This adds to the available information about substrate‐gene‐performance, and provides new information to enable engineering to regulate the colonization of Lactiplantibacillus . © 2021 Society of Chemical Industry.

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