College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, Nanjing 210095, PR China.
College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, Nanjing 210095, PR China.
Ecotoxicol Environ Saf. 2018 Oct;161:526-533. doi: 10.1016/j.ecoenv.2018.06.033. Epub 2018 Jun 18.
In this study, metal-tolerant bacteria Serratia liquefaciens CL-1 and Bacillus thuringiensis X30 were compared for their Cd and Pb immobilization in solution and impacts on biomass and Cd and Pb uptake in a radish in metal-contaminated soils under field conditions. Strains CL-1 and X30 significantly reduced water-soluble Cd and Pb concentrations (45-67%) and increased the pH in solution compared to the controls. These strains significantly increased the biomass (25-99%) and decreased edible tissue Cd and Pb uptake in the radish (37-81%) and DTPA-extractable Cd and Pb contents (18-44%) of the rhizosphere soil compared to the un-inoculated controls. Strain CL-1 had higher potential to reduce edible tissue Cd and Pb uptake in the radish and DTPA-extractable Cd content than strain X30. Also, these strains significantly increased Cd translocation factor and strain CL-1 also significantly increased Pb translocation factor of the radish. Furthermore, strain CL-1 significantly increased the ratio of small soil aggregates (< 0.25 mm and 0.25-0.50 mm) of the rhizosphere soil. The results showed that these strains reduced the edible tissue Cd and Pb uptake through decreasing Cd and Pb availability in the soil and increasing Cd or Pb translocation from the roots to the leaves of the radish. The results also suggested the bacteria-related differences in reduced heavy metal uptake in the radish and the mechanisms involved under field conditions.
在这项研究中，比较了耐金属细菌液化沙雷氏菌 CL-1 和苏云金芽孢杆菌 X30 对溶液中 Cd 和 Pb 的固定作用及其对污染土壤中萝卜生物量和 Cd 和 Pb 吸收的影响。与对照相比，菌株 CL-1 和 X30 显著降低了水溶液中可溶 Cd 和 Pb 的浓度（45-67%），并提高了溶液的 pH 值。与未接种对照相比，这些菌株显著增加了根际土壤的生物量（25-99%），降低了萝卜（37-81%）和 DTPA 可提取 Cd 和 Pb 含量（18-44%）中的可食用组织 Cd 和 Pb 吸收。与菌株 X30 相比，菌株 CL-1 更有潜力降低萝卜可食用组织中的 Cd 和 Pb 吸收量和 DTPA 可提取 Cd 含量。此外，这些菌株还显著增加了萝卜的 Cd 转移系数，而菌株 CL-1 还显著增加了 Pb 转移系数。此外，菌株 CL-1 还显著增加了根际土壤中小土壤团聚体（<0.25mm 和 0.25-0.50mm）的比例。结果表明，这些菌株通过降低土壤中 Cd 和 Pb 的有效性和增加 Cd 或 Pb 从根部向萝卜叶片的转移，降低了萝卜可食用组织中 Cd 和 Pb 的吸收。结果还表明，细菌在降低萝卜中重金属吸收方面存在差异，以及在田间条件下涉及的相关机制。
