Biodegradation of azo dyes by genetically engineered azoreductase

Article type: Research Article

Authors: WANG, Jing | YAN, Bin | ZHOU, Ji-ti | BAO, Yong-ming | LU, Hong | YUAN, Xiao-dong

Affiliations: School of Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116023, China | Takara Biotechnology Co., Ltd, Dalian 116600, China

Note: [] Corresponding author. E-mail: [email protected]

Abstract: A azoreductase gene with 537 bp was obtained by PGR amplification from Rhodobacter sphaeroides AS1.1737. The enzyme, with a molecular weight of 18.7 kD, was efficiently expressed in Escherichia coli and its biodegradation characteristics for azo dyes were investigated. Furthermore, the reaction kinetics and mechanism of azo dyes catalyzed by the genetically engineered azoreductase were studied in detail. The presence of a hydrazo-intermediate was identified, which provided a convincing evidence for the assumption that azo dyes were degraded via an incomplete reduction stage.

Keywords: genetically engineered microorganisms, azoreductase, biodegradation, azo dyes

Journal: Journal of Environmental Sciences, vol. 17, no. 4, pp. 545-550, 2005