title: [Isolation, identification and biological activity of myxobacteria from soils].
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 culture supernatant.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors: Rong
authors: R
authors: Xiao
authors: Ye
authors: Y
authors: Wen
authors: Shaojun
authors: S
authors: Tang
authors: Xinmin
authors: X
authors: Zhao
authors: Xuezhi
authors: X
authors: Ding
authors: Shengbiao
authors: S
authors: Hu
authors: Liqiu
authors: L
authors: Xia
authors: Yunjun
authors: Y
authors: Sun
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D006801:Humans; D051379:Mice; D009231:Myxococcales / Q000145:classification / Q000166:cytology / Q000302:isolation & purification* / Q000502:physiology; D009369:Neoplasms / Q000628:therapy; D010802:Phylogeny; D012988:Soil Microbiology