title: Reactive azo dye reduction by Shewanella strain J18 143.
abstract: A bacterial isolate designated strain J18 143, originally isolated from soil contaminated with textile wastewater, was shown to reduce intensely coloured solutions of the reactive azo dye, Remazol Black B to colourless solutions. Phylogenetic placement based on 16S rRNA gene sequence homology identified the bacterium as a Shewanella species. Based on results from analyses of the end products of dye decoloration of Remazol Black B and the simpler molecule, Acid Orange 7, using capillary electrophoresis, UV-visible spectrophotometry and liquid chromatography-mass spectrometry, we suggest that colour removal by this organism was a result of microbially mediated reduction of the chromophore in the dye molecules. Anaerobic dye reduction by Shewanella strain J18 143 was 30 times more efficient than the reduction carried out by aerated cultures. Whole cells used a range of electron donors for dye reduction, including acetate, formate, lactate, and nicotinamide adenine dinucleotide (NADH), with formate being the optimal electron donor. The impact of a range of process variables was assessed (including nitrate, pH, temperature, substrate concentration, presence of an extracellular mediator) and results suggest that whole cells of Shewanella J18 143 offer several advantages over other biocatalysts with the potential to treat azo dyes.
authors.affiliation: Williamson Research Centre for Molecular Environmental Science and School of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Manchester M13 9PL, UK.
authors.forename: Carolyn I
authors.initials: CI
authors.lastname: Pearce
authors.forename: Robert
authors.initials: R
authors.lastname: Christie
authors.forename: Christopher
authors.initials: C
authors.lastname: Boothman
authors.forename: Harald
authors.initials: H
authors.lastname: von Canstein
authors.forename: James T
authors.initials: JT
authors.lastname: Guthrie
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Lloyd
mesh_terms: D001391:Azo Compounds / Q000378:metabolism; D001557:Benzenesulfonates; D001673:Biodegradation, Environmental; D004396:Coloring Agents / Q000378:metabolism*; D007220:Industrial Waste; D009282:Naphthalenesulfonates / Q000378:metabolism; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000145:classification*; D020592:Shewanella / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification / Q000379:methods
chemical_list: D001391:Azo Compounds; D001557:Benzenesulfonates; D004396:Coloring Agents; D007220:Industrial Waste; D009282:Naphthalenesulfonates; D012336:RNA, Ribosomal, 16S; D014874:Water Pollutants, Chemical; C063421:Remazol black B; C014722:2-naphthol orange