title: Decolorization and biodegradation of Reactive Blue 13 by Proteus mirabilis LAG.
abstract: The decolorization and biodegradation of Reactive Blue 13 (RB13), a sulphonated reactive azo dye, was achieved under static anoxic condition with a bacterial strain identified as Proteus mirabilis LAG, which was isolated from a municipal dump site soil near Lagos, Nigeria. This strain decolorized RB13 (100mg/l) within 5h. The formation of aromatic amine prior to mineralization was supported by Fourier transform infrared spectrometry (FTIR), which revealed the disappearance of certain peaks, particularly those of the aromatic C-H bending at 600-800 cm(-1). Gas chromatography-mass spectrophotometry (GCMS) analysis of the dye metabolite showed the presence of sodium-2(2-formyl-2-hydroxyvinyl) benzoate, with a tropylium cation as its base peak, this suggested the breakage of naphthalene rings in RB13. The detection of azoreductase and laccase activities suggested the enzymatic reduction of azo bonds prior to mineralization. In addition, phytotoxicity studies indicated the detoxification of RB13 to non-toxic degradation products by this strain of P. mirabilis LAG.
authors.affiliation: Department of Biochemistry, University of Lagos, PMB 12003 Lagos, Nigeria; Department of Biochemistry, Shivaji University, Kolhapur 416004, India; Department of Chemical Sciences, Redeemer's University, PMB 3005 Redemption City, Ogun State, Nigeria. Electronic address: olukanni_olumide@yahoo.com.
authors.forename: O D
authors.initials: OD
authors.lastname: Olukanni
authors.affiliation: Department of Biochemistry, University of Lagos, PMB 12003 Lagos, Nigeria.
authors.forename: A A
authors.initials: AA
authors.lastname: Osuntoki
authors.affiliation: Department of Biochemistry, Shivaji University, Kolhapur 416004, India; Division of Chemical & Bioengineering, Konkuk University, Seoul, 1 Hwayang-Dong, Gwangjin-Gu 143-701, Republic of Korea.
authors.forename: D C
authors.initials: DC
authors.lastname: Kalyani
authors.affiliation: Department of Biochemistry, University of Lagos, PMB 12003 Lagos, Nigeria.
authors.forename: G O
authors.initials: GO
authors.lastname: Gbenle
authors.affiliation: Department of Biochemistry, Shivaji University, Kolhapur 416004, India.
authors.forename: S P
authors.initials: SP
authors.lastname: Govindwar
mesh_terms: D001673:Biodegradation, Environmental; D003116:Color; D004396:Coloring Agents / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D011513:Proteus mirabilis / Q000378:metabolism*
chemical_list: D004396:Coloring Agents