College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, Nanjing 210095, China.
College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, Nanjing 210095, China.
J Hazard Mater. 2024 Nov 5;479:135623. doi: 10.1016/j.jhazmat.2024.135623. Epub 2024 Aug 24.
In this study, the effects of the Cd-resistant and pyoverdine-producing strain Pseudomonas umsongensis CR14 on Cd stabilization and the mechanisms were investigated. Compared with the control, CR14 markedly reduced the Cd concentration in a Cd-containing solution. The genes pvdA, 4498, 4499, and pchF, which are associated with pyoverdine production, were identified in CR14. Subsequently, CR14 and the CR14ΔpvdA, CR14Δ4498, CR14Δ4499, and CR14ΔpchF mutants were characterized for their effects on Cd stabilization in solution. After 72 h of incubation, the CR14ΔpchF and CR14ΔpvdA mutants significantly decreased Cd concentrations compared with CR14. Notably, the CR14ΔpvdA mutant showed a greater impact on Cd stabilization than the other mutants. Compared with CR14, this mutant brought a lower Cd concentration in the solution, with higher levels of cell surface-adsorbed and intracellular accumulated Cd, content of lipopolysaccharide (LPS), expression of the LPS-producing genes lptD and lpxL, and cell surface particles. Additionally, compared with CR14, the CR14ΔpvdA mutant demonstrated increased interactions between the hydroxyl, carboxyl, amino, or ether groups and Cd. These results suggest that the CR14ΔpvdA mutant immobilized Cd by increasing LPS production and cell surface particle numbers, upregulating the expression of LPS-producing genes, and increasing cell surface adsorption and intracellular accumulation in Cd-polluted solutions.
在这项研究中，研究了耐镉和产绿脓菌素的假单胞菌菌株 Pseudomonas umsongensis CR14 对 Cd 稳定化的影响及其机制。与对照相比，CR14 显著降低了含 Cd 溶液中的 Cd 浓度。鉴定出与绿脓菌素产生相关的基因 pvdA、4498、4499 和 pchF 存在于 CR14 中。随后，对 CR14 及其 CR14ΔpvdA、CR14Δ4498、CR14Δ4499 和 CR14ΔpchF 突变体进行了表征，以研究它们对溶液中 Cd 稳定化的影响。孵育 72 小时后，与 CR14 相比，CR14ΔpchF 和 CR14ΔpvdA 突变体显著降低了 Cd 浓度。值得注意的是，CR14ΔpvdA 突变体对 Cd 稳定化的影响大于其他突变体。与 CR14 相比，该突变体使溶液中的 Cd 浓度更低，细胞表面吸附和细胞内积累的 Cd 含量更高，脂多糖 (LPS) 的含量更高，LPS 产生基因 lptD 和 lpxL 的表达水平更高，以及细胞表面颗粒更多。此外，与 CR14 相比，CR14ΔpvdA 突变体增加了羟基、羧基、氨基或醚基与 Cd 的相互作用。这些结果表明，CR14ΔpvdA 突变体通过增加 LPS 的产生和细胞表面颗粒数量、上调 LPS 产生基因的表达以及增加细胞表面吸附和细胞内积累来固定 Cd，从而固定 Cd。在 Cd 污染的溶液中。
