Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences (FAAS), Fuzhou 350013, China; Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou 350013, China.
Department of Engineering, Dalhousie University, Truro, NS B2N 5E3, Canada.
J Hazard Mater. 2021 Aug 15;416:125942. doi: 10.1016/j.jhazmat.2021.125942. Epub 2021 Apr 25.
A novel Ralstonia Bcul-1 strain was isolated from soil samples that was closest to Ralstonia pickettii. Broad-spectrum resistance was identified to a group of heavy metal ions and tolerance to concentrations of Cd up to 400 mg L. Low concentrations of heavy metal ions did not have distinctive impact on heavy metal resistance genes and appeared to induce greater expression. Under exposure to Cd, cell wall components were significantly enhanced, and some proteins were also simultaneously expressed allowing the bacteria to adapt to the high Cd living environment. The maximum removal rate of Cd by the Ralstonia Bcul-1 strain was 78.97% in the culture medium supplemented with 100 mg L Cd. Ralstonia Bcul-1 was able to survive and grow in a low nutrient and cadmium contaminated (0.42 mg kg) vegetable soil, and the cadmium removal rate was up to 65.76% in 9th growth. Ralstonia Bcul-1 mixed with biochar could maintain sustainable growth of this strain in the soil up to 75 d and the adsorption efficiency of cadmium increased by 16.23-40.80% as compared to biochar application alone. Results from this work suggests that Ralstonia Bcul-1 is an ideal candidate for bioremediation of nutrient deficient heavy metal contaminated soil.
从土壤样本中分离出一株新型的罗尔斯通氏菌 Bcul-1 菌株，该菌株与罗尔斯通氏菌 pickettii 最为接近。该菌株对一组重金属离子表现出广谱抗性，并能耐受高达 400mg/L 的 Cd 浓度。低浓度的重金属离子对重金属抗性基因没有明显的影响，反而似乎诱导了更高的表达。在暴露于 Cd 时，细胞壁成分显著增强，同时一些蛋白质也同时表达，使细菌能够适应高 Cd 的生存环境。在添加 100mg/L Cd 的培养基中，Ralstonia Bcul-1 菌株对 Cd 的最大去除率为 78.97%。Ralstonia Bcul-1 能够在低营养和镉污染（0.42mg/kg）的蔬菜土壤中存活和生长，在第 9 次生长时，Cd 的去除率高达 65.76%。Ralstonia Bcul-1 与生物炭混合后，可使该菌株在土壤中持续生长 75d，与单独使用生物炭相比，Cd 的吸附效率提高了 16.23-40.80%。本研究结果表明，Ralstonia Bcul-1 是一种理想的生物修复营养缺乏型重金属污染土壤的候选菌株。
