The Study Of The Surface Adhesive Proteins Of The Lactobacillus Sp.nov Isolated From The Intestine Of Paralichthys Olivaceus

Lactic acid bacteria(LAB) can act as antagonisms as they can colonize in the intestinaltract and thus exculde the pathogenic bacteria. It is a prerequisite for LAB to adhere tothe mucus or the epithelia for the efficient colonization in the intestinal tract, and theadhesins in the surface are the structural base of the adhesion. It is necessary to analyzethe adhesin(s) for elucidating the adhesive mechanism(s), and it is improtant to study theadhesive mechanism(s) deeply for improving the microecologic conditions of theenteron and the control of the invading pathogenic bacteria. Lactobacillus L15, a newstrain isolated from the intestinal tract of healthy Paralichthys olivaceus, was taken asthe experimental bacterium, and the surface protein of L15 which might be involved inthe adhesion to mucus of Paralichthys olivaceus had been primarily isolated, identifiedand purificated.The growth curve of L15 when cultured in MRS fluid medium at 37℃was measuredat first. It was demonstrated that the latent period was about six hours and next 12 hourswas the exponential period, and then the stabilized period appeared. It was concludedthat 5mol/L neutral lithium chloride was the most suitable reagent which couldeffectively extract the surface proteins from L15 compared with the 5mol/L acidiclithium chloride and the 8mol/L urea. The expression of the surface protein was variedwith temperature, time and salinity in MRS medium. It was optimum that the bacteriawere cultivated in MRS medium without NaCl under 37℃after 16h. After comparingthe SEM images of the bacteria dealt with 5mol/L neutral lithium chloride with theimages of the untreated bacteria, it could be concluded that the proteins extracted by theneutral lithium was the surface proteins because the cell of the bacteria was still intact.The adhesive property of L15 after treated with neutral lithium chloride was analyzedand it was showed that the property of L15 to adhere to the mucus was decreased afterthe treatment, so it could be concluded that the extractions had the surface adhesiveprotein(s).The method of Western blotting was used to identify the adhesive surface protein(s) ofL15. And the details of the method were as followed. After interacted with the B-NHS,the intestinal mucus of Paralichthys olivaceus was incubated with the nitrocellulose...