School of Metallurgy and Environment, Central South University, Changsha 410083, China; State Key Laboratory of Advanced Metallurgy for Non-ferrous Metals, Changsha 410083, China; National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha 410083, China; Water Pollution Control Technology Key Lab of Hunan Province, Changsha 410083, China.
School of Metallurgy and Environment, Central South University, Changsha 410083, China.
J Hazard Mater. 2024 Sep 15;477:135298. doi: 10.1016/j.jhazmat.2024.135298. Epub 2024 Jul 22.
The biogeochemical cycle of biogenic manganese oxides (BioMnOx) is closely associated with the environmental behavior and fate of various pollutants. It is significantly interfered by many metals, such as Cu and Fe. However, the bacterial molecular responses are not clear. Here, the effects of Cu(II) and Fe(III) on oxidation of manganese by Pseudomonas putida MnB1 and the bacterial molecular response mechanisms have been studied. The bacterial oxidation of manganese were promoted by both Fe(III) and Cu(II) and the final manganese oxidation rate of the Cu(II) group exceeded 16 % that of the Fe(III) group. The results of transcriptome indicated that Cu(II) promoted manganese oxidation by up-regulating the expression levels of multicopper oxidase (MCO) and peroxidase(POD), and by stimulating electron transfer, while Fe(III) promoted this process by accelerating the electron transfer and nitrogen cycling, and activating POD. The protein-protein interaction (PPI) network indicated that the MCO genes (mnxG and mcoA) were directly linked to the copper homeostasis proteins (cusA, cusB, czcC and cusF). Cytochrome c was closely related to the genes related to nitrogen cycling (glnA, glnL, and putA) and electrons transfer (cycO, cycD, nuoA, nuoK, and nuoL), which also promoted manganese oxidation. This study provides a molecular level insight into the oxidation of Mn(II) by Pseudomonas putida MnB1 with Cu(II) and/or Fe(III) ions.
生物成因锰氧化物（BioMnOx）的生物地球化学循环与各种污染物的环境行为和归宿密切相关。它受到许多金属的显著干扰，如 Cu 和 Fe。然而，细菌的分子反应尚不清楚。在这里，研究了 Cu(II)和 Fe(III)对假单胞菌 MnB1 氧化锰的影响及其细菌分子反应机制。Fe(III)和 Cu(II)都促进了细菌对锰的氧化，Cu(II)组的最终锰氧化速率超过了 Fe(III)组的 16%。转录组的结果表明，Cu(II)通过上调多铜氧化酶（MCO）和过氧化物酶（POD）的表达水平，并通过刺激电子转移来促进锰氧化，而 Fe(III)通过加速电子转移和氮循环以及激活 POD 来促进这一过程。蛋白质-蛋白质相互作用（PPI）网络表明，MCO 基因（mnxG 和 mcoA）与铜稳态蛋白（cusA、cusB、czcC 和 cusF）直接相关。细胞色素 c 与与氮循环（glnA、glnL 和 putA）和电子转移（cycO、cycD、nuoA、nuoK 和 nuoL）相关的基因密切相关，这些基因也促进了锰的氧化。本研究从分子水平上深入了解了 Pseudomonas putida MnB1 在 Cu(II)和/或 Fe(III)离子存在下氧化 Mn(II)的过程。
