Identification Of Lactobacillus Surface Protein And Immune Biological Characteristics Of Bacterial Extension Factor EF-Tu

Lactic acid bacteria is widely found in natural environment with a wide variety, and broadly applied in food, medicine and animal husbandry and other fields as probiotics. In recent years, lactic acid bacteria plays an important role in the prevention and treatment of gastrointestinal diseases, the regulation of microbial flora in the gastrointestinal tract, and improving the body immunity. However, the lactic acid bacteria can inhibit the adhesion of pathogenic bacteria by competitive adhesion and colonization of the host. Adhesion is the first step for lactic acid bacteria plays a probiotic effect, and the main adhering material is the surface protein of lactic acid bacteria. This study performed for the extraction and identification of the lactic acid bacterial surface protein, and to study the immune biological characteristics of elongation factor EF-Tu. The main results are described as follows:(1) The hydrophobicity and coagulation ability of the different lactic acid bacterial strains were measured, and the results showed that Pediococcus pentosaceus F28-8 were strongest in both hydrophobicity and coagulation abilities, while Lactobacillus plantarum HP 12 showed the weakest abilities. The extraction efficiency of different hydrophobic surface proteins of lactic acid bacteria by using the same method was different. The results showed that the efficiency of Pediococcus pentosaceus F28-8 extracting the surface protein was lowest.In contrast, the efficiency of the surface protein extracted by Lactobacillus plantarum HP 12 was the highest.(2) Taking 3 methods for extracting the surface proteins of lactic acid bacteria, and the method of extracting with 1 mg/mL lysozyme binding with 1 mol/L LiCl was most efficient. The amount of surface protein was 3 times more than the other methods by using 1 mg/mL lysozyme and 1 mol/L LiCl. Electron microscopy showed that Pediococcus pentosaceus H 13 were treated with 1 mg/ml lysozyme with 1 mol/L lithium chloride, then surface protein was dissolved, indicating that 1 mg/ml lysozyme with 1 mol/L LiCl extraction of surface proteins was the highest efficiency.(3) Identification of Pediococcus pentosaceus H13 surface protein results showed that most of the protein of the protein surface was intermediate metabolites and the transport protein, band with a variety of proteins present in the same relative molecular mass. However, the types of protein in the band of elongation factor EF-Tu were least, and the identification of the same position of Lactobacillus plantarum was only an elongation factor EF-Tu, and it had a high degree of immunogenicity, which can be used as a protein target for lactic acid bacteria strain isolation.(4) By cross reaction that elongation factor EF-Tu antisera detected bacteria and total bacteria protein of lactic acid bacteria and other non lactic acid bacteria, Escherichia coli, Salmonella and Vibrio bacteria and pyrolysis elongation factor EF-Tu antiserum to had negative reactions, and Pediococcus pentosaceus whole bacterial proteins and Lactobacillus plantarum, Lactobacillus coryniformis, Lactobacillus casei, Lactobacillus rhamnose, Lactobacillus fermentum cell andpyrolysis had positive reactions. The results showed that extension factor EF-Tu was the distinction between lactic acid bacteria and other strains of the target protein.