title: Azo dye decolorization by Shewanella aquimarina under saline conditions.
abstract: Decolorization of azo dyes under saline conditions was studied with Shewanella aquimarina, which demonstrated good growth at up to 7% NaCl. No inhibition on acid red 27 (AR27) decolorization was caused by 1-3% NaCl. Additionally, 14.5% AR27 (0.2mM) could still be removed in 12h in the presence of 10% NaCl. The relationship between specific decolorization rate and AR27 concentration followed Michaelis-Menten kinetics (K(m)=0.34 mM, V(max)=6.44 μmol mg cell(-1) h(-1)). Lactate and formate were efficient electron donors for AR27 decolorization. The initial decolorization rate was in direct proportion to biomass concentration (0.18-0.72 g l(-1)). Compared to NaCl, slighter inhibitive effects were found with Na(2)SO(4) whereas more severe inhibition was caused by NaNO(3). Lower NaCl concentration stimulated azoreductase, laccase and NADH-DCIP reductase activities of cell extracts. AR27 decolorization products were found to be aromatic amines, which were less phytotoxic than the untreated dye.
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, China.
authors.forename: Xianming
authors.initials: X
authors.lastname: Meng
authors.forename: Guangfei
authors.initials: G
authors.lastname: Liu
authors.forename: Jiti
authors.initials: J
authors.lastname: Zhou
authors.forename: Q
authors.initials: Q
authors.lastname: Shiang Fu
authors.forename: Guanghui
authors.initials: G
authors.lastname: Wang
mesh_terms: D001391:Azo Compounds / Q000302:isolation & purification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D003116:Color; D004396:Coloring Agents / Q000302:isolation & purification / Q000378:metabolism*; D054712:Salinity; D020592:Shewanella / Q000145:classification / Q000378:metabolism*; D013045:Species Specificity; D014874:Water Pollutants, Chemical / Q000302:isolation & purification / Q000378:metabolism*; D018508:Water Purification / Q000379:methods*
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D014874:Water Pollutants, Chemical