College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, Nanjing 210095, China.
College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, Nanjing 210095, China.
Microbiol Res. 2024 Oct;287:127861. doi: 10.1016/j.micres.2024.127861. Epub 2024 Jul 31.
Understanding of the mechanisms on bacteria-regulated mineral dissolution functions is important for further insight into mineral-microbe interactions. The functions of the two-component system have been studied. However, the molecular mechanisms involved in bacterial two-component system-mediated mineral dissolution are poorly understood. Here, the two-component regulatory system ResS/ResR in the mineral-solubilizing bacterium Pseudomonas pergaminensis F77 was characterized for its involvement in biotite dissolution. Strain F77 and the F77ΔresS, F77ΔresR, and F77ΔresS/R mutants were constructed and compared for the ResS/ResR system-mediated Fe and Al release from biotite in the medium and the mechanisms involved. After 3 days of incubation, the F77ΔresS, F77ΔresR, and F77ΔresS/R mutants significantly decreased the Fe and Al concentrations in the medium compared with F77. The F77ΔresS/R mutant had a greater impact on Fe and Al release from biotite than did the F77ΔresS or F77ΔresR mutant. The F77∆resS/R mutant exhibited significantly reduced Fe and Al concentrations by 21-61 % between 12 h and 48 h of incubation compared with F77. Significantly increased pH values and decreased cell counts on the mineral surfaces were found in the presence of the F77∆resS/R mutant compared with those in the presence of F77 between 12 h and 48 h of incubation. Metabolomic analysis revealed that the extracellular metabolites associated with biotite dissolution were downregulated in the F77ΔresS/R mutant. These downregulated metabolites included GDP-fucose, 20-carboxyleukotriene B4, PGP (16:1(9Z)/16:0), 3',5'-cyclic AMP, and a variety of acidic metabolites involved in carbohydrate, amino acid, and lipid metabolisms, glycan biosynthesis, and cellular community function. Furthermore, the expression levels of the genes involved in the production of these metabolites were downregulated in the F77ΔresS/R mutant compared with those in F77. Our findings suggested that the ResS/ResR system in F77 contributed to mineral dissolution by mediating the production of mineral-solubilizing related extracellular metabolites and bacterial adsorption on mineral surface.
了解细菌调控矿物溶解功能的机制对于进一步了解矿物-微生物相互作用至关重要。已经研究了双组分系统的功能。然而，细菌双组分系统介导的矿物溶解的分子机制尚不清楚。在这里，对矿物溶解菌假单胞菌 F77 中的双组分调节系统 ResS/ResR 进行了表征，以研究其在黑云母溶解中的作用。构建了 F77 及其 F77ΔresS、F77ΔresR 和 F77ΔresS/R 突变体，并比较了 ResS/ResR 系统介导的培养基中黑云母中铁和铝的释放以及涉及的机制。孵育 3 天后，与 F77 相比，F77ΔresS、F77ΔresR 和 F77ΔresS/R 突变体显著降低了培养基中的铁和铝浓度。与 F77ΔresS 或 F77ΔresR 突变体相比，F77ΔresS/R 突变体对黑云母中铁和铝的释放影响更大。与 F77 相比，F77∆resS/R 突变体在孵育 12-48 小时之间，铁和铝浓度分别降低了 21-61%。在孵育 12-48 小时之间，与 F77 相比，F77∆resS/R 突变体存在时矿物表面的 pH 值显著升高，细胞计数减少。代谢组学分析表明，与黑云母溶解相关的细胞外代谢物在 F77ΔresS/R 突变体中下调。这些下调的代谢物包括 GDP-岩藻糖、20-羧基白三烯 B4、PGP（16:1(9Z)/16:0）、3'，5'-环 AMP 和各种参与碳水化合物、氨基酸和脂质代谢、聚糖生物合成和细胞群落功能的酸性代谢物。此外，与这些代谢物产生相关的基因在 F77ΔresS/R 突变体中的表达水平低于 F77 中的表达水平。我们的研究结果表明，F77 中的 ResS/ResR 系统通过调节矿物溶解相关细胞外代谢物的产生和细菌在矿物表面的吸附，促进了矿物的溶解。
