title: Enhanced reduction of Fe(III) oxides and methyl orange by Klebsiella oxytoca in presence of anthraquinone-2-disulfonate.
abstract: Klebsiella oxytoca GS-4-08 is capable of azo dye reduction, but its quinone respiration and Fe(III) reduction abilities have not been reported so far. In this study, the abilities of this strain were reported in detail for the first time. As the biotic reduction of Fe(III) plays an important role in the biogeochemical cycles, two amorphous Fe(III) oxides were tested as the sole electron acceptor during the anaerobic respiration of strain GS-4-08. For the reduction of goethite and hematite, the biogenic Fe(II) concentrations reached 0.06 and 0.15 mM, respectively. Humic acid analog anthraquinone-2-disulfonate (AQS) was found to serve as an electron shuttle to increase the reduction of both methyl orange (MO) and amorphous Fe(III) oxides, and improve the dye tolerance of the strain. However, the formation of Fe(II) was not accelerated by biologically reduced AQS (B-AH2QS) because of the high bioavailability of soluble Fe(III). For the K. oxytoca strain, high soluble Fe(III) concentrations (above 1 mM) limit its growth and decolorization ability, while lower soluble Fe(III) concentrations produce an electron competition with MO initially, and then stimulate the decolorization after the electron couples of Fe(III)/Fe(II) are formed. With the ability to respire both soluble Fe(III) and insoluble Fe(III) oxides, this formerly known azo-reducer may be used as a promising model organism for the study of the interaction of these potentially competing processes in contaminated environments.
authors.affiliation: College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China. lyu@njfu.edu.cn.|Jiangsu Key Laboratory of Biomass Energy and Materials, Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Nanjing, 210042, China. lyu@njfu.edu.cn.
authors.forename: Lei
authors.identifier: http://orcid.org/0000-0003-3975-8903
authors.initials: L
authors.lastname: Yu
authors.affiliation: College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China.
authors.forename: Shi
authors.initials: S
authors.lastname: Wang
authors.affiliation: College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China.
authors.forename: Qing-Wen
authors.initials: QW
authors.lastname: Tang
authors.affiliation: College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China.|Jiangsu Key Laboratory of Biomass Energy and Materials, Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Nanjing, 210042, China.
authors.forename: Ming-Yue
authors.initials: MY
authors.lastname: Cao
authors.affiliation: College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Li
authors.affiliation: College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Yuan
authors.affiliation: College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, 230026, China.
authors.forename: Wen-Wei
authors.initials: WW
authors.lastname: Li
mesh_terms: D000880:Anthraquinones / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D016227:Benzoquinones / Q000737:chemistry; D003470:Culture Media / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry*; D006812:Humic Substances / Q000032:analysis; D058085:Iron Compounds / Q000737:chemistry*; D041121:Klebsiella oxytoca / Q000378:metabolism*; D008903:Minerals / Q000737:chemistry*; D008962:Models, Theoretical; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry
chemical_list: D000880:Anthraquinones; D001391:Azo Compounds; D016227:Benzoquinones; D003470:Culture Media; D005290:Ferric Compounds; D006812:Humic Substances; D058085:Iron Compounds; D008903:Minerals; D010087:Oxides; C094886:goethite; C000499:ferric oxide; C023554:anthraquinone sulfonate; C004532:quinone; C100258:methyl orange
keywords: Decolorization; Electron shuttle; Fe(III) reduction; Klebsiella oxytoca