Importance of S-layer proteins in probiotic activity of Lactobacillus acidophilus M92

Abstract

Aims:To investigate the functional role of surface layer proteins (S-layer) in probiotic strain Lactobacillus acidophilus M92, especially its influence on adhesiveness to mouse ileal epithelial cells. Methods and Results: Sodium dodecyl sulphate polyacrylamide gel electrophoresis of cell surface proteins revealed the presence of potential surface layer (S-layer) proteins, ca at 45 kDa in L. acidophilus M92. Southern blot with pBK1 plasmid, containing slpA gene, gave a positive signal, suggesting that L. acidophilus M92 has a slpA gene coding for the S-layer proteins. S-layer proteins of this strain are present during all phases of growth. The S-layer proteins appeared when cells treated with 5 mol l )1 LiCl were allowed to grow again. Removal of the S-layer proteins reduced adhesion of L. acidophilus M92 to mouse ileal epithelial cells. Furthermore, the viability of cells without S-layer were reduced in simulated gastric juice at low pH range (2, 2AE5, 3) and simulated pancreatic juice with bile salts (1AE5 and 3 g l )1 ). S-layer proteins of L. acidophilus M92 were resistant to pepsin and pancreatin, in contrast, the treatment with proteinase K led to a significant proteolysis of the S-layer proteins.Conclusions: These results demonstrated functional role of S-layer; it is responsible for adhesiveness of Lactobacillus acidophilus M92 to mouse ileal epithelial cells and has a protective role for this strain. Significance and Impact of the Study: S-layer proteins have an important role in the establishment of probiotic strain Lactobacillus acidophilus M92 in the gastrointestinal tract.

Effect of Environmental Stresses on S-Layer Production in Lactobacillus acidophilus ATCC 4356

“…amylovorus, L. gallinarum, L. crispatus, L. brevis, L. gasseri and L. johnsonii (AvallJaaskelainen & Palva, 2005;Jakava-Viljanen et al, 2002;Ventura et al, 2002). There is also increasing evidence that S-layer-carrying bacteria may use S-layer variation, by expressing alternative S-layer protein genes, for adaptation to different stress factors such as the immune response of the host for pathogens and drastic changes in the environmental conditions for nonpathogens Frece et al, 2005;Jakava-Viljanen et al, 2002;Pouwels et al, 1998;Sara & Sleytr, 2000). According to Pouwels' www.intechopen.com study (1998), phase variation or antigenic variation, as a result of inversion of the slp segment, might enable Lactobacillus acidophilus bacteria to better adhere to specific regions of the mucosa.…”

“…However, no general function has been identified for S-layer proteins, but several lactobacillar S-layers have been identified as putative adhesions with affinity for intestinal epithelial cells, extracellular matrices and/ or to lipoteichoic acid (LTA) of other bacterial species (Avall-Jaaskelainen & Palva, 2005;Buck et al, 2005;Frece et al, 2005;Garrote et al, 2004;Hynonen et al, 2002;Kos et al, 2003;Velez et al, 2007;Vidgren et al, 1992). Of the various roles proposed for the bacterial S-layer, it is a protective sheath against hostile environment (Avall-Jaaskelainen & Palva, 2005;Frece et al, 2005;Khaleghi et al, 2010Khaleghi et al, , 2011Kos et al, 2003;Schar-Zammaretti et al, 2005). Adhesive S-layers have a role in inhibition of adhesiveness of pathogenic bacteria and thus can contribute to probiotic effects of lactobacilli.…”

“…The degree of retention is likely dependent on the ability of the bacteria to interact with eukaryotic cell surfaces or with the mucosal layer surrounding these cells (Altermann et al, 2004). Several factors contribute to the interaction of Lactobacilli with the host tissues, such as cell surface hydrophobicity (Vadillo-Rodriguez et al, 2005;Van der Mei et al, 2003), autoaggregation (Kos et al, 2003), lipoteichoic acids (Granato et al, 1999) and external surface proteins (such as S-layer, fibronectin and mucinbinding proteins) (Altermann et al, 2004;Avall-Jaaskelainen & Palva, 2005;Frece et al, 2005;Kos et al, 2003;Kosin & Rakshit, 2006;Pouwels et al, 1998;Velez et al, 2007;Ventura et al, 2002). Surface layer (S-layer) has been identified as the outermost structure of cell envelope in numerous organisms from the domains Bacteria (in both Gram-positive and Gramnegative Eubacteria) and Archaea (Debabov, 2004;Sara & Sleytr, 2000).…”

Sortase-deficient lactobacilli: effect on immunomodulation and gut retention

“…L. acidophilus NCK2232 and L. gasseri NCK2256 were evaluated for growth in MRS and survival in simulated gastric juices (SGJs) and small intestinal juices (SIJs) (Charteris et al, 1998;Frece et al, 2005;Goh & Klaenhammer, 2010) and compared to the parent strains L. acidophilus NCK1909 and L. gasseri NCK2253, respectively. For growth studies, the growth in MRS broth (2 % inoculum from a stationary phase culture) was monitored for 12 h at OD 600 and viable cells (c.f.u.…”

Xylan-mediated aggregation of Lactobacillus brevis and its relationship with the surface properties and mucin-mediated aggregation of the bacteria

“…[31][32][33][34] However, the mechanism responsible for the probiotic effects of intestinal bacteria remains unclear, and an examination of the adhesion properties of Lactobacillus using plant materials such as xylan had not been previously conducted. Thus, this study, which described the Fig.…”