Adhesion properties of <i>Lactobacillus rhamnosus</i> mucus-binding factor to mucin and extracellular matrix proteins

<div><p>We previously described potential probiotic <i>Lactobacillus rhamnosus</i> strains, isolated from fermented mare milk produced in Sumbawa Island, Indonesia, which showed high adhesion to porcine colonic mucin (PCM) and extracellular matrix (ECM) proteins. Recently, mucus-binding factor (MBF) was found in the GG strain of <i>L. rhamnosus</i> as a mucin-binding protein. In this study, we assessed the ability of recombinant MBF protein from the FSMM22 strain, one of the isolates of <i>L. rhamnosus</i> from fermented Sumbawa mare milk, to adhere to PCM and ECM proteins by overlay dot blot and Biacore assays. MBF bound to PCM, laminin, collagen IV, and fibronectin with submicromolar dissociation constants. Adhesion of the FSMM22 <i>mbf</i> mutant strain to PCM and ECM proteins was significantly less than that of the wild-type strain. Collectively, these results suggested that MBF contribute to <i>L. rhamnosus</i> host colonization via mucin and ECM protein binding.</p></div>