Phenol–Quinone Redox Couples of Natural Organic Matter Promote Mercury Methylation in Paddy Soil

Environmental Science & Technology, Journal Year: 2025, Volume and Issue: 59(2), P. 1179 - 1188

Published: Jan. 7, 2025

Methylmercury in paddy soils poses threats to food security and thus human health. Redox-active phenolic quinone moieties of natural organic matter (NOM) mediate electron transfer between microbes mercury during reduction. However, their role methylation remains elusive. Here, artificial (AOM), i.e., biochar, wherein the phenol–quinone ratio associated redox properties varied, was used as a redox-tunable model NOM investigate impact couples on Hg-contaminated soils. Our findings confirm that AOM with higher ratios (i.e., donor capacities) stimulated microbial (4.9-fold increase) dark abiotic (2.2-fold increase). The had contrasting effects abundance Hg gene hgcA metabolic genes corresponding Hg-methylating demethylating clades dsrA, dsrB, mcrA, pmoA), especially under anaerobic (simulated flooding) conditions. key methylators were from Geobacteraceae, including Oryzomonas, Fundidesulfovibrio, Geomobilimonas. driven by further validated such humic fulvic acids. Notably, observed aerobic sterilized soil, yet additional evidence is necessary potential pathway, hampered difficulty identifying effective methyl donors soil. results reveal drive methylation, offering novel insights into

Language: Английский

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Selective utilization of organic carbon molecules promotes arsenic methylation by increasing methyltransferase activity in arsM-harboring microbes of paddy soils

Soil Biology and Biochemistry, Journal Year: 2024, Volume and Issue: 190, P. 109305 - 109305

Published: Jan. 2, 2024

Language: Английский

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Expression Levels of hgcAB Genes and Mercury Availability Jointly Explain Methylmercury Formation in Stratified Brackish Waters

Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(18), P. 13119 - 13130

Published: Sept. 7, 2022

Neurotoxic methylmercury (MeHg) is formed by microbial methylation of inorganic divalent Hg (HgII) and constitutes severe environmental human health risks. The enabled hgcA hgcB genes, but it not known if the associated molecular-level processes are rate-limiting or enable accurate prediction MeHg formation in nature. In this study, we investigated relationships between hgc genes across redox-stratified water columns brackish Baltic Sea. We showed, for first time, that transcript abundance concentration dissolved HgII-sulfide species were strong predictors both HgII rate concentration, implying their roles as principal joint drivers these systems. Additionally, characterized metabolic capacities hgc+ microorganisms reconstructing genomes from metagenomes (i.e., MAGs), which highlighted versatility putative methylators column establishing transcripts rate, advance fundamental understanding mechanistic principles governing nature refined predictions levels coastal seas response to accelerating spread oxygen-deficient zones.

Language: Английский

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Using the end-member mixing model to evaluate biogeochemical reactivities of dissolved organic matter (DOM): autochthonous versus allochthonous origins

Water Research, Journal Year: 2023, Volume and Issue: 232, P. 119644 - 119644

Published: Jan. 18, 2023

Language: Английский

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Anthropogenic activities enhance mercury methylation in sediments of a multifunctional lake: Evidence from dissolved organic matter and mercury-methylating microorganisms

Journal of Hazardous Materials, Journal Year: 2024, Volume and Issue: 466, P. 133505 - 133505

Published: Jan. 12, 2024

Language: Английский

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Recyclable magnetic-responsive AC/Fe3O4/UiO-66 adsorbents for removing elemental mercury from flue gas

Separation and Purification Technology, Journal Year: 2024, Volume and Issue: 353, P. 128395 - 128395

Published: June 16, 2024

Language: Английский

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Abatement of algal extracellular organic matter by vacuum ultraviolet: Effect of dissolved oxygen and role of in-situ formed reactive oxygen species

Journal of Water Process Engineering, Journal Year: 2024, Volume and Issue: 66, P. 106028 - 106028

Published: Aug. 23, 2024

Language: Английский

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Mercury Reduction, Uptake, and Species Transformation by Freshwater Alga Chlorella vulgaris under Sunlit and Dark Conditions

Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(8), P. 4961 - 4969

Published: April 7, 2022

As a major entry point of mercury (Hg) to aquatic food webs, algae play an important role in taking up and transforming Hg species ecosystems. However, little is known how what extent reduction, uptake, transformations are mediated by algal cells their exudates, organic matter (AOM), under either sunlit or dark conditions. Here, using Chlorella vulgaris (CV) as one the most prevalent freshwater model species, we show that solar irradiation could enhance reduction mercuric Hg(II) elemental Hg(0) both CV AOM. AOM reduced more than themselves due cell surface adsorption uptake inside irradiation. Synchrotron radiation X-ray absorption near-edge spectroscopy (SR-XANES) analyses indicate sunlight facilitated transformation less bioavailable such β-HgS Hg-phytochelatins, compared Hg(Cysteine)2-like formed dark. These findings highlight functional roles potential mechanisms immobilization varying lighting conditions these processes may modulate cycling bioavailability environment.

Language: Английский

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Impact of dissolved organic matter and environmental factors on methylmercury concentrations across aquatic ecosystems inferred from a global dataset

Chemosphere, Journal Year: 2022, Volume and Issue: 294, P. 133713 - 133713

Published: Jan. 21, 2022

Language: Английский

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Mercury in wetlands over 60 years: Research progress and emerging trends

The Science of The Total Environment, Journal Year: 2023, Volume and Issue: 869, P. 161862 - 161862

Published: Jan. 28, 2023

Language: Английский

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