Abstract:In order to select probiotic strains with high adhesion capability to turbot intestinal mucus and understand the adhesion mechanism of Rhodotorula glutinis, the ability of Rhodotorula glutinis, Lactobacillus rhamnosus, Candida sp. and Bacillus subtilis adhering to the intestinal mucus of turbot (Scophthatmus maximus) was investigated in vitro, adhesion protein of Rhodotorula glutinis and mucus receptor were also identified. The results indicate all of the four probiotic strains can adhere to turbot intestinal mucus and significantly better than the BSA treatment. Adhesion percent of R. glutinis to intestinal mucus is the highest among the four probiotic strains. C. ethanolica and B. subtilis adhere to intestinal mucus but weakly. Forthermore, adhesion of R. glutinis to intestinal mucus was quantitatively inhibited by graded concentration of surface protein extracted from R. glutinis. However, the surface protein have no effect on the attachment of C. ethanolica and other two strains to the intestinal mucus. The adhesion protein extracted from the R. glutinis cell surface and intestinal mucus isolated from turbot intestine was visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, native polyacrylamide gel electrophoresis and was identified by Western-blotting with horseradish peroxidase-labeled mucus or surface proteins. The results show that 38.5 ku and 28.6 ku protein of cell surface extraction involved in adherence of R. glutinis to mucus. Two kinds of protein in mucus can be recognized by the surface proteins of R. glutinis, the relative molecular weight is 27.3 ku and 22.3 ku, respectively. The above four kinds of proteins were identified as glycoproteins by PAS methods.