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

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.

摘要：从污染填埋场土壤中分离得到的厦门希瓦氏菌（Shewanella xiamenensis）G5-03，在静置条件下可高效脱色五种纺织偶氮染料。其中活性红239（Reactive Red 239，RR239）可在35℃、pH 7至11的范围内，于3~6小时内被该菌株完全脱色。该菌株在pH 8、25~40℃的宽温度区间内，同样可高效脱色RR239。G5-03催化RR239脱色的动力学过程符合米氏动力学模型（Michaelis-Menten Model），其米氏常数Km为443.3 mg·L⁻¹，最大反应速率Vmax为166.7 mg·L⁻¹·h⁻¹。通过紫外-可见分光光度法（UV-Vis）与傅里叶变换红外光谱法（FTIR）对RR239的脱色过程进行监测，结果显示其特征峰位与原染料光谱相比发生了显著变化。综上，厦门希瓦氏菌G5-03可在宽温度与pH（中性至碱性）范围内完成纺织偶氮染料的脱色，表明该菌株具备用于含染料废水处理的潜在应用价值。