title: Chemotaxis to atrazine and detection of a xenobiotic catabolic plasmid in Arthrobacter sp. DNS10.
abstract: BACKGROUND
  A plasmid named pDNS10 was detected from an atrazine-degrading strain Arthrobacter sp. DNS10 which has been isolated previously in our laboratory.
  
  
  METHODS
  In this paper, a special plasmid-detecting method and drop assays experiments were mainly used to achieve research goals.
  
  
  CONCLUSIONS
  pDNS10 exhibited an excellent stability because it also could be detected even when the strain DNS10 has been subcultured under nonselective conditions for eight times. Over a 48-h incubation period, the OD(600) of samples inoculated with strain DNS10 and strain DNS10-ST (both of them contained pDNS10) were 0.31 ± 0.042 and 0.305 ± 0.034, respectively ,whereas the OD(600) of samples inoculated strain without pDNS10 (strain DNS10-PE) was only 0.138 ± 0.018. No atrazine was detected in the inoculated strain DNS10 and strain DNS10-ST samples at this period. Contrarily, the atrazine-degrading rate of strain DNS10-PE was only 5.23 ± 0.71%. Furthermore, both the two types of strains containing pDNS10 confirmed the presence of known degrading genes such as trzN, atzB, and atzC. It suggests that pDNS10 is an atrazine catabolic plasmid. In drop assays experiments, the wild-type strain DNS10 cells were chemotactically attracted to atrazine, whereas strain DNS10-PE showed no chemotaxis to atrazine and hydroxyatrazine. There was some relationship between atrazine degradation and the chemotactic response towards atrazine in strain DNS10.
  
  
  CONCLUSIONS
  The biochemical characteristics of pDNS10 and the chemotaxis characteristics of strain DNS10 could help us in better understanding of the mechanism of atrazine degradation by strain DNS10.
authors.affiliation: School of Resources & Environment, Northeast Agricultural University, Harbin, 150030, People's Republic of China. zhangyinghr@hotmail.com
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zhao
authors.initials: Z
authors.lastname: Jiang
authors.forename: Bo
authors.initials: B
authors.lastname: Cao
authors.forename: Miao
authors.initials: M
authors.lastname: Hu
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Wang
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Dong
mesh_terms: D001173:Arthrobacter / Q000187:drug effects* / Q000502:physiology; D001280:Atrazine / Q000378:metabolism* / Q000494:pharmacology*; D001673:Biodegradation, Environmental; D002633:Chemotaxis / Q000187:drug effects* / Q000502:physiology; D006540:Herbicides / Q000378:metabolism; D015394:Molecular Structure; D010957:Plasmids / Q000378:metabolism*
chemical_list: D006540:Herbicides; D001280:Atrazine