Department of Environmental Health Engineering, School of Health, Rafsanjan University of Medical Sciences, Rafsanjan, Iran.
Environmental Science and Technology Research Center, Department of Environmental Health Engineering, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
World J Microbiol Biotechnol. 2019 Feb 9;35(3):38. doi: 10.1007/s11274-019-2608-y.
The present study investigated biodegradation and removal of Reactive Red 198 (RR198) dye from aqueous environments using a new bacterial consortium isolated from textile wastewater sludge on laboratory scale via batch study. Two bacterial species, Enterococcus faecalis (EF) and Klebsiella variicola (KV), were identified after isolation, through biochemical assays, Polymerase chain reaction (PCR), and 16S rRNA gene sequencing. To determine their ability to biodegrade RR198 dye, physicochemical parameters, including bacterial concentration, time, pH, and temperature, were tested; the results showed that the best conditions included a bacterial concentration of 3.5 mL × 10 cells/mL and incubation time of 72 h. Under such conditions, the removal efficiency of RR198 dye at an initial concentration of 10-25 mg/L was more than 98%; however, for concentrations of 50, 75, and 100 mg/L, removal efficiency was reduced to 55.62%, 25.82%, and 15.42%, respectively (p = 0.005). The highest removal efficiency occurred at pH 8.0, reaching 99.26% after 72 h of incubation. With increasing the incubation temperature from 25 °C to 37 °C, removal efficiency increased from 71.71 to 99.26% after 72 h of incubation, and increasing the temperature from 37 to 45 °C, the removal efficiency was reduced (p ≤ 0.001). Therefore, the EF-KV bacterial consortium can be used for efficient removal of RR198 dye from textile effluent.
本研究采用实验室规模的分批实验，从纺织废水污泥中分离出一种新型细菌混合体，研究了该混合体对活性红 198（RR198）染料在水相环境中的生物降解和去除作用。通过生化分析、聚合酶链反应（PCR）和 16S rRNA 基因测序，对分离出的两种细菌，粪肠球菌（EF）和肺炎克雷伯菌（KV）进行鉴定。为了确定它们对 RR198 染料的生物降解能力，测试了包括细菌浓度、时间、pH 值和温度在内的理化参数；结果表明，最佳条件包括细菌浓度为 3.5 mL×10 细胞/mL 和孵育时间为 72 h。在此条件下，初始浓度为 10-25 mg/L 的 RR198 染料的去除效率超过 98%；然而，对于浓度为 50、75 和 100 mg/L 的 RR198 染料，去除效率分别降低至 55.62%、25.82%和 15.42%（p=0.005）。在 pH 值为 8.0 时，去除效率最高，孵育 72 h 后达到 99.26%。随着孵育温度从 25°C 升高至 37°C，孵育 72 h 后去除效率从 71.71%升高至 99.26%，而当温度从 37°C 升高至 45°C 时，去除效率降低（p≤0.001）。因此，EF-KV 细菌混合体可用于有效去除纺织废水中的 RR198 染料。
