title: [Characterization of salicylate 5-hydroxylase for phenanthrene degradation using moderately halophilic Martelella sp. AD-3].
abstract: OBJECTIVE
  To identify the relationship between salicylate 5-hydroxylase activity and the degradation rate of phenanthrene by moderately halophilic Martelella sp. AD-3, and to investigate their enzymatic characteristics.
  
  
  METHODS
  The products resulted from degradation of salicylic acid using the crude enzyme produced by AD-3 was analyzed using HPLC analysis, and salicylate 5-hydroxylase activities at different conditions was calculated according to the change of NADH absorbance at 340 nm.
  
  
  RESULTS
  The salicylate 5-hydroxylase activity was higher during log-phase and early stationary phase of AD-3, and the enzyme activity was in consistent with phenanthrene degradation rate. The enzyme production was induced by phenanthrene and salicylic acid. The highest enzyme activity, 132.8 nmol/(min x mg), from strain AD-3 was obtained under the phenanthrene concentration of 200 mg/L, 3% salinity and a pH of 9.0. The optimum conditions for degradation of salicylic acid using this enzyme were 30 degrees C , pH 7.5, and salinity 3%. The V(max) and K(m) for the enzyme were 200 nmol/(min x mg) and 8.7 micromol/L, respectively.
  
  
  CONCLUSIONS
  The salicylate 5-hydroxylase was produced in the degradation of phenanthrene in AD-3. The enzyme activity was related to phenanthrene degradation rate.
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China. dongfei86@gmail.com
authors.forename: Fei
authors.initials: F
authors.lastname: Dong
authors.forename: Changzheng
authors.initials: C
authors.lastname: Cui
authors.forename: Tiancai
authors.initials: T
authors.lastname: Feng
authors.forename: Yaoyu
authors.initials: Y
authors.lastname: Feng
authors.forename: Yongdi
authors.initials: Y
authors.lastname: Liu
mesh_terms: D020561:Alphaproteobacteria / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001673:Biodegradation, Environmental; D004795:Enzyme Stability; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000378:metabolism*; D010616:Phenanthrenes / Q000737:chemistry / Q000378:metabolism*; D020156:Salicylic Acid / Q000378:metabolism; D012965:Sodium Chloride / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D010616:Phenanthrenes; C031181:phenanthrene; D012965:Sodium Chloride; D006899:Mixed Function Oxygenases; C099614:salicylic acid 5-hydroxylase; D020156:Salicylic Acid