title: Isolation and characterization of Pseudomonas aeruginosa strain SJTD-2 for degrading long-chain n-alkanes and crude oil.
abstract: OBJECTIVE
  Oil pollution poses a severe threat to ecosystems, and bioremediation is considered as a safe and efficient alternative to physicochemical.
  
  
  METHODS
  for eliminating this contaminant. In this study, a gram-negative bacteria strain SJTD-2 isolated from oil-contaminated soil was found capable of utilizing n-alkanes and crude oil as sole energy sources. The efficiency of this strain in degrading these pollutants was analyzed.
  
  
  METHODS
  Strain SJTD-2 was identified on the basis of its phenotype, its physiological features, and a comparative genetic analysis using 16S rRNA sequence. Growth of strain SJTD-2 with different carbon sources (n-alkanes of different lengths and crude oil) was assessed, and the gas chromatography-mass spectrometry method was used to analyze the degradation efficiency of strain SJTD-2 for n-alkanes and petroleum by detecting the residual n-alkane concentrations.
  
  
  RESULTS
  Strain SJTD-2 was identified as Pseudomonas aeruginosa based on the phenotype, physiological features, and 16S rRNA sequence analysis. This strain can efficiently decompose medium-chain and long-chain n-alkanes (C10-C26), and petroleum as its sole carbon sources. It preferred the long-chain n-alkanes (C18-C22), and n-docosane was considered as the best carbon source for its growth. In 48 h, 500 mg/L n-docosane could be degraded completely, and 2 g/L n-docosane was decomposed to undetectable levels within 72 h. Moreover, strain SJTD-2 could utilize about 88% of 2 g/L crude oil in 7days. Compared with other alkane-utilizing strains, strain SJTD-2 showed outstanding degradation efficiency for long-chain n-alkanes and high tolerance to petroleum at elevated concentrations.
  
  
  CONCLUSIONS
  The isolation and characterization of strain SJTD-2 would help researchers study the mechanisms underlying the biodegradation of n-alkanes, and this strain could be used as a potential strain for environmental governance and soil bioremediation.
authors.forename: Jing
authors.initials: J
authors.lastname: Xu
authors.forename: Huan
authors.initials: H
authors.lastname: Liu
authors.forename: Jianhua
authors.initials: J
authors.lastname: Liu
authors.forename: Rubing
authors.initials: R
authors.lastname: Liang
mesh_terms: D000473:Alkanes / Q000737:chemistry / Q000378:metabolism*; D001673:Biodegradation, Environmental; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010578:Petroleum / Q000032:analysis / Q000378:metabolism*; D010802:Phylogeny; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D012988:Soil Microbiology
chemical_list: D000473:Alkanes; D010578:Petroleum