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

posted on 04.12.2019 by Aline Silva Cossolin, Hélen Cristina Oliveira dos Reis, Ketinny Camargo de Castro, Bruna Assis Paim dos Santos, Matheus Zimermann Marques, Carlos Adriano Parizotto, Evandro Luiz Dall´Oglio, Leonardo Gomes de Vasconcelos, Eduardo Beraldo de Morais

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.