土壤样品中粘细菌的分离鉴定及其生物活性检测

Isolation，identification and biological activity of myxobacteria from soils

摘要:

摘要:【目的】从土壤样品中分离粘细菌，对其进行纯化、归类与鉴定，以丰富粘细菌菌种资源;对纯化得到的粘细菌进行抑菌、杀虫及抗肿瘤生物活性的分析，为粘细菌次级代谢产物的开发奠定基础。【方法】采用灭活大肠杆菌和滤纸片诱导子实体法从土样中分离粘细菌，结合形态观察、生理生化特征和16S rDNA基因序列同源性分析，对分离到的各菌株进行鉴定并归类。通过平板扩散法、昆虫口服毒性测试、肿瘤细胞毒性实验等方法，检测粘细菌代谢产物生物活性。【结果】共分离得到35株粘细菌，初步分类为:粘球菌属(Myxococcus) 9株;珊瑚球菌属(Corallococcus) 9株;侏囊菌属(Nannocystis) 11株;堆囊菌属(Sorangium) 6株。从其中纯化得到8株粘细菌，对其进行了鉴定并命名。发现了具有高效且广谱的肿瘤细胞毒性效应菌株S22，S51和S55也具同样的细胞毒性;另外，还发现具有肿瘤细胞毒性的菌株S20和S22对枯草芽胞杆菌和白色念珠菌也具有较好的抑菌活性。【结论】土壤中存在丰富的粘细菌资源，发现了具有肿瘤细胞毒性的弱小珊瑚球菌与具有抑菌和强抗肿瘤活性的大孢珊瑚球菌，粘细菌是活性天然产物与新药开发的重要资源。

Abstract:

Abstract:: ［Objective］Purpose of this work was to screen myxobacteria from soils and study their biological activities towards pathogenic bacteria，tumor cells and insects.［Methods］Through inactivated E．coli and filter paper inducing methods，we isolated and purified myxobacteria from soil samples．Then we identified these purified strains based on morphological observation，physiological and biochemical characteristics，and the 16S rDNA sequences homologous analysis．By plate diffusion experiments，oral toxicity tests and tetrazolium assays，we investigated the biological activities of the myxobacterial culturesupernatant.［Results］We isolated 35 myxobacterial strains and classified them as 4 genera: Myxococcus (9)，Corallococcus (9)，Nannocystis (11) and Sorangium (6)．Eight purified myxobacteria were identified and named．Cytotoxicity tests show that strain C.macrospores S22 had potent and broad-spectrum cytotoxic effect on tumor cell lines including B16，4T1，HeLa and HCT-116，so did the strains M．fulvus S51，C．exiguus S22 and M．Xanthus S55． Additionally，C．macrospores S22 also shows inhibitory activity to pathogenic bacteria Bacillus subtillis and Candida albicans．［Conclusion］Myxobacteria are widely distributed in natural soils．C．macrosporus has potent toxicity against cancer cells and pathogenic bacteria; and C．exiguus with antitumor activity．The myxobacterial strains are promising resources for discovery and development of new active natural products and drugs．