title: Anaerobic biodecolorization mechanism of methyl orange by Shewanella oneidensis MR-1.
abstract: In this work, we investigated the anaerobic decolorization of methyl orange (MO), a typical azo dye, by Shewanella oneidensis MR-1, which can use various organic and inorganic substances as its electron acceptor in natural and engineered environments. S. oneidensis MR-1 was found to be able to obtain energy for growth through anaerobic respiration accompanied with dissimilatory azo-reduction of MO. Chemical analysis shows that MO reduction occurred via the cleavage of azo bond. Block of Mtr respiratory pathway, a transmembrane electron transport chain, resulted in a reduction of decolorization rate by 80%, compared to the wild type. Knockout of cymA resulted in a substantial loss of its azo-reduction ability, indicating that CymA is a key c-type cytochrome in the electron transfer chain to MO. Thus, the MtrA-MtrB-MtrC respiratory pathway is proposed to be mainly responsible for the anaerobic decolorization of azo dyes such as MO by S. oneidensis.
authors.affiliation: Department of Chemistry, University of Science & Technology of China, Hefei, China.
authors.forename: Pei-Jie
authors.initials: PJ
authors.lastname: Cai
authors.forename: Xiang
authors.initials: X
authors.lastname: Xiao
authors.forename: Yan-Rong
authors.initials: YR
authors.lastname: He
authors.forename: Wen-Wei
authors.initials: WW
authors.lastname: Li
authors.forename: Jian
authors.initials: J
authors.lastname: Chu
authors.forename: Chao
authors.initials: C
authors.lastname: Wu
authors.forename: Meng-Xing
authors.initials: MX
authors.lastname: He
authors.forename: Zhe
authors.initials: Z
authors.lastname: Zhang
authors.forename: Guo-Ping
authors.initials: GP
authors.lastname: Sheng
authors.forename: Michael Hon-Wah
authors.initials: MH
authors.lastname: Lam
authors.forename: Fang
authors.initials: F
authors.lastname: Xu
authors.forename: Han-Qing
authors.initials: HQ
authors.lastname: Yu
mesh_terms: D000693:Anaerobiosis; D001391:Azo Compounds / Q000378:metabolism*; D004734:Energy Metabolism; D017353:Gene Deletion; D053858:Metabolic Networks and Pathways / Q000235:genetics; D010084:Oxidation-Reduction; D020592:Shewanella / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D001391:Azo Compounds; C100258:methyl orange