title: Bioaugmentation on decolorization of C.I. Direct Blue 71 by using genetically engineered strain Escherichia coli JM109 (pGEX-AZR).
abstract: The study showed that Escherichia coli JM109 (pGEX-AZR), the genetically engineered microorganism (GEM) with higher ability to decolorize azo dyes, bioaugmented successfully the dye wastewater bio-treatment systems to enhance C.I. Direct Blue 71 (DB 71) decolorization. The control and bioaugmented reactors failed at a around pH 5.0. However, the bioaugmented one succeeded at around pH 9.0, the influent DB 71 concentration was 150 mg/L, DB 71 concentration was decreased to 27.4 mg/L in 12h. The 1-3% NaCl concentration of bioaugmented reactors had no definite influence on decolorization, DB 71 concentration was decreased to 12.6 mg/L in 12h. GEM was added into anaerobic sequencing batch reactors (AnSBRs) to enhance DB 71 decolorization. Continuous operations of the control and bioaugmented AnSBRs showed that E. coli JM109 (pGEX-AZR) could bioaugment decolorization. The concentrations of activated sludge and GEM were still more than 2.80 g/L and 1.5 x 10(6)cells/mL, respectively, in the bioaugmented AnSBR. All the microbial communities changed indistinctively with time. The microbial community structures of the control AnSBR were similar to those of the bioaugmented one.
authors.affiliation: School of Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116023, PR China.
authors.forename: Ruofei
authors.initials: R
authors.lastname: Jin
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
authors.forename: Aili
authors.initials: A
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Guangfei
authors.initials: G
authors.lastname: Liu