School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Sci Total Environ. 2022 Mar 20;813:152668. doi: 10.1016/j.scitotenv.2021.152668. Epub 2021 Dec 25.
The toxic metal(loid)s TMs resistant bacterium Brevundimonas diminuta was isolated for the first time from mines polluted soil in Fengxian, China, and assessed for its potential for Cd and Zn precipitation in Cd and Zn co-contaminated aqueous solution at various Cd and Zn levels (20, 40, 80, 160, and 200 mg L), pH values (5, 6, 7, 8, and 9), and temperatures (20, 25, 30, and 35 °C). B. diminuta showed a high resistance to both Cd and Zn and was able to precipitate up to 99.2 and 99.7% of dissolved Cd and Zn respectively, at a pH of 7 and temperature of 30 °C. B. diminuta reduced the dissolved concentrations of Cd and Zn below the threshold levels in water. The 3D-EEM analysis revealed the presence of extracellular polymeric substances (EPS) such as tryptophan indicating bacterial growth under Cd/Zn stress. FTIR showed polysaccharides, CO, CaCO, PO, and proteins, which may enhance bacterial growth and metal precipitation. SEM-EDS confirmed the leaf-like and granular shape of the biological precipitation and reduction in the percent weight of TMs, which promoted the adhesion/adsorption of Cd, Zn, and Ca. Moreover, XRD analysis confirmed the precipitation of Cd, Zn, and Ca in the form of CdCO/Cd(PO), ZnCO/ZnHPO/Zn(OH)PO/Zn(PO), and CaCO/Ca(PO)OH, respectively. These findings indicate that Brevundimonas diminuta can be used for the bioremediation of TMs-contaminated aquatic environments.
首次从中国奉贤矿区污染土壤中分离出耐毒金属（类）细菌 Brevundimonas diminuta，并评估其在不同 Cd 和 Zn 水平（20、40、80、160 和 200mg/L）、pH 值（5、6、7、8 和 9）和温度（20、25、30 和 35°C）下对 Cd 和 Zn 共污染水溶液中 Cd 和 Zn 沉淀的潜力。B. diminuta 对 Cd 和 Zn 均具有高抗性，在 pH 值为 7 和温度为 30°C 时，分别可沉淀高达 99.2%和 99.7%的溶解 Cd 和 Zn。B. diminuta 将溶解的 Cd 和 Zn 浓度降低到水中的阈值以下。3D-EEM 分析表明存在胞外聚合物物质（EPS），如色氨酸，表明细菌在 Cd/Zn 胁迫下生长。FTIR 显示多糖、CO、CaCO、PO 和蛋白质，这可能增强细菌的生长和金属沉淀。SEM-EDS 证实了生物沉淀的叶状和颗粒状形状以及 TM 重量百分比的降低，这促进了 Cd、Zn 和 Ca 的粘附/吸附。此外，XRD 分析证实了 Cd、Zn 和 Ca 以 CdCO/Cd(PO)、ZnCO/ZnHPO/Zn(OH)PO/Zn(PO)和 CaCO/Ca(PO)OH 的形式沉淀。这些发现表明 Brevundimonas diminuta 可用于受 TM 污染的水生环境的生物修复。
