Physiological Characteristic Research And Comparative Proteomic Analysis Of Bifidobacterium Longum XY01

Bifidobacterium longum XY01is an excellent medicinal probiotic strain and has obviousstrain-specificity. It is of great theoretical significance and shows potentials versatileapplications, such as biochemical characteristics, proteomics, comment secreted proteins anddifferential proteomics information.In this work, the secreted proteins and whole-cell protein in different periods of B.longum XY01were prepared for research and that of B. longum NCC2705were introduced asa reference. Two-dimensional electrophoresis technique and mass spectrometry method wereapplied to analyze the secreted proteins and differential proteome function information. Wealso made a deeply study of the physiological and biochemical characteristics of the strains.The highlights of the work were listed in the following.The fermentation broth displayed strong growth inhibitory activities to Micrococcusflavus NCIB8166, and the antibacterial activity of B. longum XY01was stronger than that ofB. longum NCC2705. The contents of lactic acid and acetic acid in the fermentation broth ofB.longum XY01were6.44g/L and3.81g/L analyed by gas chromatography technique, whilein the fermentation broth of B.longum NCC2705, lactic acid was7.25g/L, the acetic acidcontent of B.longum NCC2705was very low. Moreover, bothB. longum XY01and NCC2705had strong adhesive ability to the Hela cells, theadhesion index of B. longum XY01to Hela cells was3.79±3.03, stronger than that ofB. longum NCC2705（1.94±1.99）.Good repeatability and high resolution2-D profiles of the secretory and whole-cellprotein were obtained by using adhesive strip with pH4-7and pH3-10in two-dimensional gel electrophoresis.18secretory protein spots were successfullyidentified in B. longum XY01which displayed14species protein, while38secretoryprotein spots were picked out in B. longum NCC2705which standed for23species protein.Most of the secretory proteins in B. longum XY01were cytoderm/cytomembrane associatedproteins and mainly located in cytoplasm, extracellular and cytoderm. There were9signalpeptide proteins and2peptidoglycan biosynthesis proteins. In B.longum NCC2705, Manysecretory proteins were functional protein and located in the cytoplasmic, including10signalpeptide proteins and3glycolytic pathway proteins. These secreted proteins are involved inthe signal transduction, cell wall/membrane synthesis, the energy generation and conversion,nutrient transport mechanisms and cell adhesion effect. Detailed information of the secretorywas acquired in this work, and it provided basic information for clarifying the interaction ofthe Bifidobacterium longum and its host.In this work,105different protein spots were expressed in Whole-cell protein profilesand98protein spots were successfully identified which represented76species proteins. Theseproteins were highly expressed in B. longum XY01, and involved in galactose metabolism,glycolysis, purine and pyrimidine metabolism and secondary metabolites synthesis. Therewere6proteins involved in galactose metabolism in the B. longum XY01. These proteinsdemonstrate that the B. longum XY01are stronger than B. longum NCC2705in the metabolic activity and adaptability. Interestingly, the Bifid Shunt glucose metabolism of B. longumXY01are more active which can produce a large number of metabolites, especially organicacids, which is a key factor of prebiotic in the body.