Nanomaterials
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2024
·Vol. 14
·期 6
·512
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IF 4.4
Yuan Chen,Jiaxing Wang,Daidi Chen,Boxi Wang,Jinchuan Wu,Rongrong Liu,Qingxin Li
Many studies have been conducted on the microbial reduction of Pd (II) to palladium nanoparticles (Pd-NPs) due to the environmental friendliness, low cost, and the decreased toxicity of Pd (II) ions. In this study, we investigate the reduction mechanism of Pd (II) byBacillus megateriumY-4 through proteomics. The data are available via ProteomeXchange with identifier PXD049711. Our results revealed thatB. megateriumY-4 may use the endogenous electron donor (NAD(P)H) generated by nirB, tdh, and fabG and reductase to reduce Pd (II) to Pd-NPs. The expression levels of fabG, tdh, gudB, and rocG that generate NAD(P)H were further increased, and the number of reduced Pd-NPs was further increased with the exogenous electron donor sodium formate. Endogenous electron mediators such as quinones and flavins inB. megateriumY-4 can further enhance Pd (II) reduction. The findings provided invaluable information regarding the reduction mechanism of Pd (II) byB. megateriumY-4 at the proteome level.
研究领域:
微生物学
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环境科学
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产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
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2024
·
IF 9.7
Linya Yi,Shuyan Chen,Yuancai Chen
Bio-remediation are low-cost and environmentally friendly, but microbial enzymes tend to lose their activity when treated antibiotic contaminants due to its high toxicity. In this study, Bacillus megaterium Y-4 was demonstrated to in situ synthesize Pd 0 @cells, and detoxify oxytetracycline (OTC) through enhancing electron transport chain via Pd 0 -dependent F O F 1 -ATPase (proton pumps). Toxicity analyses showed that increasing Pd 0 loading significantly reduced acute and chronic bio-toxicity as well as ecological risk of OTC effluent, as evidenced by the promoting cellular response to oxidative stress with increasing enzymes GSH-Px and IDH activities (4.24 and 1.20-fold). Electrochemical (I-t, LSV, DPV and EDC) showed that the incorporated bio-Pd 0 mainly promoted FDH/Hase-based short chain (gradually took precedence over CoQ-based long chain), diverting OTC extracellular degradation to markedly detoxify OTC to cell. Inhibition (DCCD and TBA) assays and structural equation modelling indicated that bio-Pd 0 upregulated ATP and NADH synthesis. It also acted as transmembrane F O F 1 -ATPase proton pump, which enabled the backward of protons out of the restriction of PMF , eventually maximizing the energy utilization. This study sheds new insights into the detoxification of antibiotics by bio-nanoparticles through proton transmembrane transfer/redistribution.
研究领域:
微生物学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Yuan Chen,Keqiang Hu,Yuancai Chen
In this study, we screened a new aerobic bacterium ( Bacillus megaterium Y-4) that can efficiently reduce Pd(II) with different electron donors. The best electron donor was sodium formate and the best reduction of Pd(II) were by log growth phase cells. The high removal capacity of Pd(II) (1658.3 mg/g) was obtained with 30 mg/L dry cell weight and 50 mg/L Pd (II) in the presence of 5 mM sodium formate. The removal amount of Pd(II) increased with initial Pd(II) concentrations ranging from 50 to 200 mg/L with 100 mg/L Pd(II) being completely removed by 148 mg/L dry cell weight in 6 h. The cell wall, periplasmic space and intracellular contents of B . megaterium Y-4 contains different kinds of enzymes for reducing Pd(II). In addition, the activity of extracellular and periplasmic enzymes was more sensitive to temperature than intracellular enzymes . XRD and XPS analysis revealed that the enzyme for reducing Pd(II) in B. megaterium Y-4 can tolerate a broad range of temperatures (20–60 °C) and pH (2.0–7.0) but was sensitive to oxygen. TEM analysis showed that biogenic palladium nanoparticles (Pd-NPs) were mainly distributed evenly in the periplasmic space of the live cells and were released from cells into aqueous solution, which reduced the toxicity of Pd(II), allowing Pd-NP recovery without cell destruction. B. megaterium Y-4 is a potential bacterium for efficient treatment and reclamation of Pd(II) pollution and formation of Pd-NPs.
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DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Yating Jia,Jing Lu,Yongfen Long,Bin Hou,Yuancai Chen
Microbially synthesized palladium nanoparticles (bio-Pd 0 ) hold great promise for catalysis, but the catalytic activity of bio-Pd 0 relies heavily on its subcellular localization. Electron donors could affect enzymatic reduction efficiency of Pd(II) and control the subcellular location of bio-Pd 0 , yet the underlying mechanisms were unclear. Here, the regulatory mechanism of electron donors on Pd(II) reduction pathways in the non-model bacterium B. megaterium Y-4 was comprehensively investigated by multiple methodologies including cell fractionation, DPV/CV, XPS, FTIR, TEM, proteomics. Key findings revealed that membrane-bound hydrogenases drove periplasmic Pd 0 synthesis via biohydrogen, while the new one-electron extracellular transfer (EET) channel consisting of membrane-attached cytochromes ( ccsB ) and multi-heme cytochromes-bound flavin mediated the extracellular Pd(II) reduction. Notably, electron donors could regulate Pd(II) reduction routes, thereby altering the subcellular distribution of bio-Pd 0 . In lactate-added systems, the higher expression of these proteins related to EET processes (NADH dehydrogenase, membrane-attached cytochrome c, heme-based electron transfer proteins and flavodoxin) promoted extracellular Pd 0 formation (65.4 %). Whereas, in formate-added systems, hydrogenase-driven periplasmic Pd 0 synthesis (64.0 %) was facilitated due to more active formate dehydrogenase, hydrogenase and NADPH-reducing hydrogenase. Moreover, synergistical metabolism of formate and lactate balanced both pathways and maximized the apparent Pd(II) reduction efficiency (98.13 %). Proteomic analysis confirmed formate-specific energy rewiring and compensatory energy via Na⁺-translocating Rnf complex and V-ATPase overexpression. These findings significantly advance our understanding of microbial metal reduction by delineating a true dual-pathway strategy in a Gram-positive bacterium, highlighting the mechanistic diversity beyond model Gram-negative systems and offering new insights for harnessing non-model organisms in biocatalysis and nanoparticle synthesis.
研究领域:
微生物生物技术
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纳米生物技术
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环境微生物学
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蛋白质组学
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生物无机化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）