title: Alkaline extracellular reduction: isolation and characterization of an alkaliphilic and halotolerant bacterium, Bacillus pseudofirmus MC02.
abstract: OBJECTIVE
  To isolate an alkaliphilic bacterium and to investigate its ability of extracellular reduction.
  
  
  RESULTS
  An alkaliphilic and halotolerant humus-reducing anaerobe, Bacillus pseudofirmus MC02, was successfully isolated from a pH 10·0 microbial fuel cell. To examine its ability of extracellular reduction, AQDS (anthraquinone-2, 6-disulfonae), humic acids (HA) and Fe(III) oxides were chosen as representative electron acceptors. All the experiments were conducted in a pH 9·5 carbonate buffer. The results are as follows: (i) Sucrose, lactate, glucose and glycerol were the favourable electron donors for AQDS reduction by the strain MC02; (ii) The strain had the ability of reducing HA in the presence of sucrose; (iii) It could effectively reduce Fe(III) oxides coupled with sucrose fermentation when AQDS was added as electron shuttle and its Fe(III) reducing capacity ranked as: lepidocrocite (γ-FeOOH) > goethite (α-FeOOH) > haematite(α-Fe(2) O(3) ); (iv) The strain could decolourize azo dye Orange I.
  
  
  CONCLUSIONS
  Bacillus pseudofirmus MC02 was capable of extracellular reduction in AQDS, HA and Fe(III) oxides, and it can be used for decolourizing azo dye (Orange I) in alkaline conditions.
  
  
  CONCLUSIONS
  This is the first report of an alkaliphlic strain of B. pseudofirmus capable of extracellular reduction in AQDS, HA, Fe(III) oxides and decolourization of Orange I. This study could provide valuable information on alkaline biotransformation in the printing and dyeing wastewater and saline-alkali soil.
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
authors.forename: C
authors.initials: C
authors.lastname: Ma
authors.forename: L
authors.initials: L
authors.lastname: Zhuang
authors.forename: S G
authors.initials: SG
authors.lastname: Zhou
authors.forename: G Q
authors.initials: GQ
authors.lastname: Yang
authors.forename: Y
authors.initials: Y
authors.lastname: Yuan
authors.forename: R X
authors.initials: RX
authors.lastname: Xu
mesh_terms: D000880:Anthraquinones / Q000378:metabolism; D001407:Bacillus / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000378:metabolism; D001673:Biodegradation, Environmental; D005290:Ferric Compounds / Q000378:metabolism; D006812:Humic Substances; D010084:Oxidation-Reduction; D010802:Phylogeny; D012988:Soil Microbiology
chemical_list: D000880:Anthraquinones; D005290:Ferric Compounds; D006812:Humic Substances; C042834:9,10-anthraquinone; C000499:ferric oxide