Screening Of Mutant Strains Of Lactobacillus LW-1 And LJG-1 Active Substance

Currently, cancer, diabetes, leukemia and other diseases, are serious threats to human health, there are few effective drugs to treatment for these diseases,and all over the world are looking for effective drugs to treatment for these diseases..Natural products with the diverse structural features and interesting biological activities are an important source of drugs. Rational screening of high quality natural products resources can greatly improve the chances of new compounds as well as new skeleton.Trichoderma is a genus of fungi that is present in all soils, where they are the most prevalent culturable fungi. Many species in this genus can be characterized as opportunistic avirulent plant symbionts. Some Trichoderma sp. product enzymes and antibiotic, and were used as bio-control agents against plant diseases. Trichoderma has great potential for development in industrial and agricultural production, Trichoderma sp. ave been increasingly investigated.In the thesis, two strains of Trichoderma sp.(No. LJG-1and LW-1) were explored for bioactive secondary metabolites. By using the modern chromatographic separation techniques, and mass spectrometry(MS), nuclear magnetic resonance(NMR), electronic circular dichroism(CD), nine compounds were isolatedfrom Trichoderma sp., of them, three compounds are known structures, and six are new compounds.Compounds 1–7 and hydroxylation product 8 were tested for cytotoxicity against K562(human myelogenous leukemia) and HCT116(human colon carcinoma) and HepG2(human hepatocellular liver carcinoma) cell lines by the MTT assay. Compounds 1, 2, and 7 showed cytotoxic effects against K562 with IC50 values of 12.12, 13.08, and 25.17 μM, respectively(the positive control taxol showed an IC50 value of 0.34 μM).While the use of UV mutagenesis techniques of Trichoderma LW-1 and LJG-1 UV mutagenesis. Select the appropriate UV irradiation time and distance.Fatality rate is calculated after mutagenesis. After mutagenesis picked a better growing colonies were inoculated into the medium, 30 days after its fermentation HPLC analysis to compare the original strain as a control, the mutation rate is calculated and analyzed its research and production and other aspects of phenotypic.