title: RETRACTED:  Aerobic degradation of 4-nitroaniline (4-NA) via novel degradation intermediates by Rhodococcus sp. strain FK48.
abstract: An aerobic strain, Rhodococcus sp. strain FK48, capable of growing on 4-nitroaniline (4-NA) as the sole source of carbon, nitrogen, and energy has been isolated from enrichment cultures originating from contaminated soil samples. During growth studies with non- induced cells of FK48 catalyzed sequential denitrification (release of NO₂ substituent) and deamination (release of NH₂ substituent) of 4-NA. However, none of the degradation intermediates could be identified with growth studies. During resting cell studies, 4-NA-induced cells of strain FK48 transformed 4-NA via a previously unknown pathway which involved oxidative hydroxylation leading to formation of 4-aminophenol (4-AP). Subsequent degradation involved oxidated deamination of 4-AP and formation of 1,2,4-benzenetriol (BT) as the major identified terminal aromatic intermediate. Identification of these intermediates was ascertained by HPLC, and GC-MS analyses of the culture supernatants. 4-NA-induced cells of strain FK48 showed positive activity for 1,2,4-benzenetriol dioxygenase in spectrophotometric assay. This is the first conclusive study on aerobic microbial degradation of 4-NA and elucidation of corresponding metabolic pathway.
authors.affiliation: Institute of Microbial Technology (CSIR), Sector 39-A, Chandigarh 160 036, India.
authors.forename: Fazlurrahman
authors.initials: F
authors.lastname: Khan
authors.affiliation: Institute of Microbial Technology (CSIR), Sector 39-A, Chandigarh 160 036, India.
authors.forename: Janmejay
authors.initials: J
authors.lastname: Pandey
authors.affiliation: Institute of Microbial Technology (CSIR), Sector 39-A, Chandigarh 160 036, India.
authors.forename: Surendra
authors.initials: S
authors.lastname: Vikram
authors.affiliation: Institute of Microbial Technology (CSIR), Sector 39-A, Chandigarh 160 036, India.
authors.forename: Deepika
authors.initials: D
authors.lastname: Pal
authors.affiliation: Institute of Microbial Technology (CSIR), Sector 39-A, Chandigarh 160 036, India. Electronic address: ssc@imtech.res.in.
authors.forename: Swaranjit Singh
authors.initials: SS
authors.lastname: Cameotra
mesh_terms: D000332:Aerobiosis; D000814:Aniline Compounds / Q000378:metabolism*; D001483:Base Sequence; D001673:Biodegradation, Environmental; D049308:Dioxygenases / Q000378:metabolism; D008969:Molecular Sequence Data; D010105:Oxygenases / Q000378:metabolism; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012240:Rhodococcus / Q000302:isolation & purification / Q000502:physiology*; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D000814:Aniline Compounds; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012989:Soil Pollutants; C019498:4-nitroaniline; D010105:Oxygenases; D049308:Dioxygenases