Decolorization of textile azo dye Reactive Red 239 by the novel strain Shewanella xiamenensis G5-03 isolated from contaminated soil

Descoloração do corante têxtil azo Reactive Red 239 por uma nova linhagem Shewanella xiamenensis G5-03 isolada de solo contaminado

Abstract

Shewanella xiamenensis G5-03 isolated from contaminated landfill soil efficiently decolorized five textile azo dyes under static conditions. One of them, Reactive Red 239 (RR239), was completely decolorized at a pH range of 7 to 11 (at 35°C) within 3-6 h. The bacterium was also efficiently decolorized RR239 in a wide temperature range of 25-40°C (at pH 8). The kinetics of RR239 decolorization by G5-03 fitted to the Michaelis-Menten Model (K _m = 443.3 mg L^-1, V _max = 166.7 mg L^-1 h^-1). The decolorization of RR239 was monitored by UV-Vis and FTIR spectroscopy, which showed significant changes in peak positions when compared to the dye spectrum. Overall, the ability of S. xiamenensis G5-03 to decolorize textile azo dyes in a wide range of temperatures and pH (neutral-alkaline) indicate that this strain is a potential candidate for treating dye-containing effluent.

Keywords:
bacterium; biodegradation; FTIR; kinetic study; Reactive Red 239.