title: [Isolation and purification and toxigenic characteristic identification of microcystis].
abstract: OBJECTIVE
  To establish methods of isolation and purification of microcystis, and to identify it's biological property.
  
  
  METHODS
  By the means of 96 well microplates and utmost dilution, microcystis was isolated and purified from Xiliu Lake of Zhengzhou. Absorbency of isolated microcystis was determined by visble light spectrophotometric method, and it's growth curve was ploted, calculated growth rate constant and double time. Toxigenicity of isolated microcystis was identified by means of the Whole cell PCR and ELISA, and the concentration of microcystin in crude extractive solution from freeze-dried microcystis cells was determined by ELISA.
  
  
  RESULTS
  Two strains of microcystis, Microcystis XLH6 and Microcystis XLH10 were isolated successfully from Xiliu Lake. Their growth curves were "S" style, their growth rate constants rapidly ascended firstly, and then slowly descended. Average growth rate constants of the two strains were 0.294 and 0.345, average double times of the two strains were 82h and 70h, respectively. The results of the Whole cell PCR and ELISA of the two strains were positive, and both of them were toxigenic. Every milligram of freeze-dried Microcystis XLH6 and Microcystis XLH10 produced 1.4microg and 2.4microg microcystin.
  
  
  CONCLUSIONS
  Xiliu Lake was polluted by toxigenic microcystis. 96 well microplates can be used to isolate microcystis.
authors.affiliation: Institute for Environmental Health and Related Product Safety, Chinese Center for Disease Control and Prevention, Beijing 100021, China.
authors.forename: Haiqun
authors.initials: H
authors.lastname: Ban
authors.forename: Xuemin
authors.initials: X
authors.lastname: Cheng
authors.forename: Huizhen
authors.initials: H
authors.lastname: Zhang
authors.forename: Jingyuan
authors.initials: J
authors.lastname: Zhu
mesh_terms: D002681:China; D046508:Culture Techniques; D052998:Microcystins / Q000032:analysis / Q000096:biosynthesis* / Q000633:toxicity; D046931:Microcystis / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D014873:Water Pollutants / Q000032:analysis*; D014881:Water Supply / Q000032:analysis*
chemical_list: D052998:Microcystins; D014873:Water Pollutants; C078588:microcystin