The Screening Of Anti-staphylococcus Aureus Bacterial Strains Of Tibetan Swine And Analysis Of Its Effective Substance

The Tibetan swine is precious local breed in Tibetan plateau with characteristics that isroughage tolerant, disease resistant, adaptation to the harsh climate and so on. Tibetan swinecan normally grow and do not sick under the extreme environment. there may be a strongantibacterial substances in vivo. In order to study the mechanism of disease resistance ofTibetan swine, the faeces of healthy adult Tibetan swine were collected as test materials, Wegot an anti-Staphylococcus aureus bacterial strains by second screening in LB medium. Theantibiotics were isolated to study its physical and chemical characteristics. The mainconclusions are as follows.1、Fecal microbes were initially screened using the Oxford cup method, after using thefermentation liquid to screen broad-spectrum antibacterial activity. The bacterial strain A wasgot against S.aureus and MRSA growth。2、 After the exclusion effect of organic acids and organic bases on Staphylococcusaureus, MRSA and other bacteria, proteinase K was used to treat fermentation broth andprotein content was measured by bicinchoninic acid(BCA) BCA, we got a conclusion thatantibacterial substances produced by A strains were polypeptides.3、Through the optimization of the fermentation conditions and fermentation medium ofstrain A, the best culture conditions is under temperature30℃, centrifugated by225rpm for24h and the best medium additive is peptone0.5g, yeast extract0.25g, NaCl0.5g, glucose(50mL)0.25g.4、The fermentation liquid of strain A were purified by the reversed phase highperformance liquid chromatography (RP-HPLC) and anti-bacteria activity showed that the3peaks and20peaks（Elution curve according to the hydrophobic） has strong inhibitoryactivity on Staphylococcus aureus.