title: Biodegradation of 4-chloroaniline by bacteria enriched from soil.
abstract: 4-Chloroaniline has been released into the environment due to extensive use in chemical industries and intensive agriculture; hence, it becomes one of the hazardous pollutants in the priority pollutant list. In this study, three gram-negative bacteria were enriched and isolated from agricultural soil as 4-chloroaniline-degrading bacteria. They were identified as Acinetobacter baumannii CA2, Pseudomonas putida CA16 and Klebsiella sp. CA17. They were able to utilize 4-chloroaniline as a sole carbon and nitrogen source without stimulation or cocultivation with aniline or another cosubstrate. The biodegradation in these bacteria was occurred via a modified ortho-cleavage pathway of which the activity of chlorocatechol 1, 2-dioxygenase was markedly induced. They grew well on 0.2-mM 4-chloroaniline exhibiting a 60-75% degradation efficiency and equimolar liberation of chloride. The isolates were able to survive in the presence of 4-chloroaniline at higher concentrations (up to 1.2 mM). 2-Chloroaniline, 3-chloroaniline and aniline, but not 3, 4-dichloroaniline, were also growth substrates for these isolates. The results of cosubstrate supplementation illustrated the suitable conditions of each isolate to improve growth rate and 4-chloroaniline biodegradation efficiency. These results suggest that these isolates have a potential use for bioremediation of the site contaminated with 4-chloroaniline.
authors.affiliation: Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, Thailand. alisa.v@chula.ac.th
authors.forename: Alisa S
authors.initials: AS
authors.lastname: Vangnai
authors.forename: Wansiri
authors.initials: W
authors.lastname: Petchkroh
mesh_terms: D040981:Acinetobacter baumannii / Q000302:isolation & purification / Q000378:metabolism; D000814:Aniline Compounds / Q000378:metabolism*; D003470:Culture Media; D006090:Gram-Negative Bacteria / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D007709:Klebsiella / Q000302:isolation & purification / Q000378:metabolism; D016958:Pseudomonas putida / Q000302:isolation & purification / Q000378:metabolism; D012988:Soil Microbiology; D013045:Species Specificity; D013379:Substrate Specificity
chemical_list: D000814:Aniline Compounds; D003470:Culture Media; C004658:4-chloroaniline