Functional Analysis of Putative Adhesion Factors in Lactobacillus acidophilus NCFM

作者：B. Logan Buck, Eric Altermann, Tina Svingerud, Todd R. Klaenhammer · 发表于：Applied and Environmental Microbiology · 年份：2005 · DOI：10.1128/aem.71.12.8344-8351.2005 · 被引用次数：386 · 研究领域：Probiotics and Fermented Foods、Microbial Metabolites in Food Biotechnology、Helicobacter pylori-related gastroenterology studies

Lactobacilli are major inhabitants of the normal microflora of the gastrointestinal tract, and some select species have been used extensively as probiotic cultures. One potentially important property of these organisms is their ability to interact with epithelial cells in the intestinal tract, which may promote retention and host-bacterial communication. However, the mechanisms by which they attach to intestinal epithelial cells are unknown. The objective of this study was to investigate cell surface proteins in Lactobacillus acidophilus that may promote attachment to intestinal tissues. Using genome sequence data, predicted open reading frames were searched against known protein and protein motif databases to identify four proteins potentially involved in adhesion to epithelial cells. Homologous recombination was used to construct isogenic mutations in genes encoding a mucin-binding protein, a fibronectin-binding protein, a surface layer protein, and two streptococcal R28 homologs. The abilities of the mutants to adhere to intestinal epithelial cells were then evaluated in vitro. Each strain was screened on Caco-2 cells, which differentiate and express markers characteristic of normal small-intestine cells. A significant decrease in adhesion was observed in the fibronectin-binding protein mutant (76%) and the mucin-binding protein mutant (65%). A surface layer protein mutant also showed reduction in adhesion ability (84%), but the effect of this mutation is likely due to the...