Adhesion Of Lactobacillus Acidophilus ATCC4356 In The Gastrointestinal Tract Of Different Animals

Lactobacillus acidophilus, an important probiotic, is a major member of the commensal flora in the gastrointestinal tracts of humans and animals. Adhesion is the first step of bacterial colonization in the gastrointestinal tract. The surface-layer protein of Lactobacillus acidophilus was though to mediate the bacterial adhesion to the intestinal epithelia and promote the the bacterial colonization in the gastrointestinal tract. It results in a series of probiotic effects exerted to their hosts. It is helpful for elucidation of adhesion mechanism and application of probiotics to investigate the interaction of surface proteins from Lactobacillus acidophilus with intestinal mucus.The S-layers protein was extracted from Lactobacillus acidophilus by 8 M guanidine hydrochloride, 5 M neutral LiCl and 5 M acidic LiCl with different treatment time and temperature, respectively. The optimized extraction method as well as the optimized temperature and time of extraction were obtained by using the Gel-pro software. It was showed that the maximumal concentration and purity of S-layer protein was obtained by extracting with 5 M acidic LiCl at 25℃for 15 min.The intestines of common carp, native chicken, Zelanian rabbit, Kunming mice were cut and rinsed with sterile PBS buffer (ph9.5) aseptically. The intestianl mucus was obtained by scraping the intestianl surface and centrifugation. The bacterial surface proteins were obtained by treatment with 5 M acidic LiCl. The Western-blots were conducted respectively by using biotin-NHS-labled intestinal mucus and surface proteins. It were revealed by DAB that the S-layer protein from Lactobacillus acidophilus was played important roles in adhesion of bacterial surface proteins to intestianl mucus of common carp, native chicken, Zelanian rabbit, Kunming mice. The S-layer protein in Lactobacillus acidophilus is a 43.6 kDa protein, called SA protein. Moreover,several proteins in intestinal mucus of common carp, native chicken, Zelanian rabbit, Kunming mice was found as mucus adhesion-promoting protein in different animals. They were 35 kDa protein for rabbit and 55kDa protein for Kunming mice characterized by western-blotting, which were considered as the recepotors for S-layer protein. But, it were seemed there were no specific mucus adhesion-promoting proteins found in the intestinal mucus of common carp and native chicken for too many protein bands visualized on the nitrocellulose membrane.In conclusion, the S-layer protein in Lactobacillus acidophilus was the main mucus adhesion-promoting protein characterized the interaction of bacterial surface protein and animal intestinal mucus. The adhesion-associated proteins in intestianl mucus were different with animals. The simple and specific protein bands were found in the intestinal mucus of highly evolved animals.