title: [Screening of chlorobenzene-degrading bacterium and purification of its degradation enzyme].
abstract: OBJECTIVE
  We screened a bacterial strain capable of degrading chlorobenzene, and purified the corresponding degradation enzyme.
  
  
  METHODS
  The strain was screened by gradient enrichment culture and sterile filter paper plate method, and identified by morphology and 16S rRNA gene sequence. Chlorobenzene concentration in the liquid culture was determined by gas chromatography. Degradation capability was assayed by the proportion of chlorobenzene degraded per cells. The purity quotient and molecular weight of the purified degradation enzyme were determined by gel per cell. electrophoresis.
  
  
  RESULTS
  The isolated bacterium, LW13, used chlorobenzene in activated sludge as sole carbon and energy source. Cells were 2.3 microm long and 0.8 microm wide, with several terminal flagella. Strain LW13 was 95.5% similar to Lysinibacillus fusiformis, and its degradation enzyme was a positively-charged exoenzyme (molecular weight about 57 kDa). The optimal temperature and pH of the purified enzyme were approximately 40 degrees C and 8.0, respectively.
  
  
  CONCLUSIONS
  Strain LW13 belongs to genus Lysinibacillus, and can degrade chlorobenzene (500-2000 mg/L).
authors: School of Chemical and Biological Engineering, Yancheng Institute of Technology, Yancheng 224051, China. lzxdzc@163.com
authors: Zhaoxia
authors: Z
authors: Li
authors: Xian
authors: X
authors: Niu
authors: Wenyi
authors: W
authors: He
authors: Yanyan
authors: Y
authors: Tong
authors: Hui
authors: H
authors: Jin
authors: Cheng
authors: C
authors: Ding
mesh_terms: D001419:Bacteria / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D001673:Biodegradation, Environmental; D002722:Chlorobenzenes / Q000378:metabolism*; D004789:Enzyme Activation; D004798:Enzymes / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S; D013696:Temperature
chemical_list: D002722:Chlorobenzenes; D004798:Enzymes; D012336:RNA, Ribosomal, 16S; C031294:chlorobenzene