Isolation of a Highly Thermostable Bile Salt Hydrolase With Broad Substrate Specificity From Lactobacillus paragasseri

• Published in: Frontiers in microbiology 2022-02, Vol.13, p.810872-810872
• Main Authors: Kusada, Hiroyuki, Arita, Masanori, Tohno, Masanori, Tamaki, Hideyuki
• Format: Article
• Language: English
• Subjects: bile salt hydrolase; Lactobacillus paragasseri; Microbiology; probiotics; substrate specificity; thermostability
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2022.810872

Bile salt hydrolase (BSH) enzymes produced by intestinal species have been recognized as major targets for probiotic studies owing to their weight-loss and cholesterol-lowering effects. In this study, we isolated a highly thermostable BSH with broad substrate specificity, designed as LapBSH (BSH from a probiotic bacterium, JCM 5343 ). The recombinant LapBSH protein clearly hydrolyzed 12 different substrates, including primary/secondary, major/minor, and taurine/glycine-conjugated bile salts in mammalian digestive tracts. Intriguingly, LapBSH further displayed a highly thermostable ability among all characterized BSH enzymes. Indeed, this enzyme retained above 80% of its optimum BSH activity even after 6 h of incubation at 50-90°C. LapBSH also exerted a functionally stable activity and maintained above 85% of its original activity after pre-heating at 85°C for 2 h. Therefore, LapBSH is a very unique probiotic enzyme with broad substrate specificity and high thermostability. The strain itself, JCM 5343 , was also found to exhibit high heat-resistance ability and could form colonies even after exposure to 85°C for 2 h. As thermostable enzyme/bacterium offers industrial and biotechnological advantages in terms of its productivity and stability improvements, both thermostable LapBSH and thermotolerant JCM 5343 could be promising candidates for future probiotic research.