Reply on RC1 DOI Creative Commons
Keyi Cheng

Published: June 5, 2024

Abstract. Iodine abundance in marine carbonates (as an elemental ratio with calcium – I:Ca) is of broad interest as a proxy for local/regional ocean redox. This connection arises because the speciation iodine seawater—in terms balance between iodate (IO3-) and iodide (I-)—is sensitive to prevalence oxic vs. anoxic conditions. However, although I:Ca ratios are being increasingly commonly measured ancient carbonate samples, fully quantitative interpretation this hindered by scarcity mechanistic framework cycle its sensitivity extent intensity deoxygenation. Here we present evaluate representation cycling embedded Earth system model (‘cGENIE’) against both modern paleo observations. In this, account IO3- uptake reduction primary producers, occurrence ambient water column, plus re-oxidation I- IO3-. We develop test variety different relationships IO­3- updated compilation observed dissolved concentrations present-day ocean. optimizing parameters controlling previously proposed mechanisms behind cycling, find that can obtain matches gradients zonal surface distribution, depth profiles, oxygen deficient zones (ODZs). also identify alternative, equally well performing which assume more explicit link transformation environment. ambiguity highlights need process-based studies on cycling. Finally, our ultimate motivation further ability reconstruct oxygenation geological past, conducted ‘plausibility tests’ various schemes available measurements made Cretaceous time substantially depleted availability compared hence strong model. Overall, simultaneous match achieve modelled observations, forward-proxy supports application modelling simulating help interpret constrain redox evolution past oceans.

Language: Английский

Molecular mechanisms of antibiotic inhibition on microbial dissimilatory iron reduction DOI

Bowei Ouyang,

Ziyue Lv,

Gan Cui

et al.

Journal of Hazardous Materials, Journal Year: 2025, Volume and Issue: unknown, P. 138348 - 138348

Published: April 1, 2025

Language: Английский

Citations

0
Distinct mechanisms of stibnite (Sb2S3) oxidative dissolution mediated by acid-generating and alkali-generating microorganisms within a wide pH range DOI
Liyuan Ma, Junhua Zhang, Weikang Gao

et al.

Journal of Hazardous Materials, Journal Year: 2025, Volume and Issue: unknown, P. 138141 - 138141

Published: April 1, 2025

Language: Английский

Citations

0
Spatial distribution and formation mechanisms of high‑iodine groundwater throughout China DOI
Junxia Li,

Shilin Zhao,

Zhou Jiang

et al.

Earth-Science Reviews, Journal Year: 2025, Volume and Issue: unknown, P. 105134 - 105134

Published: April 1, 2025

Language: Английский

Citations

0
The Competitive/Cooperative Dynamics of Sulfur Disproportionation Microbes and Methanogens in Geogenic High-Iodine Groundwater Systems DOI

Yuxiao Xu,

Yamin Deng,

Jiangkai Xue

et al.

Environmental Science & Technology, Journal Year: 2025, Volume and Issue: unknown

Published: May 7, 2025

The microbial transformation of iodine-bearing organic matter (OM) and iron (Fe) minerals is a critical process that controls the release iodine (I) to groundwater. However, roles functional types, OM molecular characteristics, microbe-OM interactions in mobilization remain unclear. In this study, groundwater samples with different concentrations were collected from central Yangtze River basins, China. Using 16S rRNA gene sequencing, we identified sulfur disproportionation methanogenesis as dominant metabolic processes relatively low-I (<300 μg/L) high-I (>300 groundwater, respectively. Sediment incubation experiments showed combined can promote by 87.1%. Ultrahigh-resolution characterization components revealed sulfur-disproportionating microbes may selectively metabolize bioactive (e.g., aliphatic compounds oxygen-poor highly unsaturated compounds), leaving recalcitrant N-containing oxygen-rich compounds, polyphenols, polycyclic aromatic compounds) methanogenic preferentially consume Thus, cooperative-competitive pattern between methanogens disproportionating microorganisms influence degradation potentially contribute mobilization. This study highlights process, driven biological methanogenesis, promotes enrichment alluvial-lacustrine improves our understanding genesis geogenic high-iodine systems.

Language: Английский

Citations

0
Isotope-Based Characterization of Soil Elemental Mercury Emissions from Historical Mercury Mining Areas: Driving Pathways and Relative Contributions DOI
Qingyi Cao, Haiyan Hu, Wei Yuan

et al.

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 10, 2024

Photo-, microbial, and abiotic dark reduction of soil mercury (Hg) may all lead to elemental (Hg(0)) emissions. Utilizing lab incubations, isotope signatures Hg(0) emitted from mining soils were characterized quantify the interplay contributions various Hg pathways, which have been scarcely studied. At 15 °C, microbial reduced showed a negative mass-dependent fractionation (MDF) (δ

Language: Английский

Citations

1
Dissimilatory Iodate-Reducing Microorganisms Contribute to the Enrichment of Iodine in Groundwater DOI
Junxia Li,

W. X. Fang,

Chengkun Li

et al.

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(43), P. 19255 - 19265

Published: Oct. 17, 2024

Iodate reduction by dissimilatory iodate-reducing microorganisms (DIRMs) plays a crucial role in the biogeochemical cycling of iodine on Earth. However, occurrence and distribution DIRMs iodine-rich groundwater remain unclear. In this study, we isolated bacterium

Language: Английский

Citations

1
The successive reduction of iodate to iodide driven by iron redox cycling DOI
S.Q. Zhu, Zhou Jiang, Yongguang Jiang

et al.

Journal of Hazardous Materials, Journal Year: 2024, Volume and Issue: 480, P. 136436 - 136436

Published: Nov. 8, 2024

Language: Английский

Citations

1
The crucial and versatile roles of bacteria in global biogeochemical cycling of iodine DOI
Zhou Jiang, Yongguang Jiang, Yidan Hu

et al.

Deleted Journal, Journal Year: 2024, Volume and Issue: 1

Published: Jan. 1, 2024

Abstract Iodine (I) is a trace element with health and environmental significance. Iodate (IO 3 - ), iodide (I ) organic iodine (org-I) are the major species of that exist in environment. Dissimilatory IO -reducing bacteria reduce to I directly under anoxic conditions via their reductases include periplasmic iodate reductase IdrABP 1 P 2 , extracellular DMSO DmsEFAB metal MtrCAB. IdrAB hypoiodous acid (HIO) H O . The reaction intermediate HIO proposed be disproportionated abiotically into at ratio 2:1. reduced by IdrP MtrCAB as detoxification mechanism. Additionally, dissimilatory Fe(III)- sulfate-reducing indirectly reduction products Fe(II) sulfide presence Fe(III) sulfate, respectively. -oxidizing oxidize molecular oxic multicopper oxidases IoxAC. In addition variety org-I compounds also produced during oxidation. Furthermore, ammonia-oxidizing conditions, probably intracellular enzymes. Many produce reactive oxygen can triiodide ). Bacteria accumulate which oxidized vanadium iodoperoxidases. then transported bacterial cells. Finally, methylate CH I, methyltransferases. Thus, play crucial versatile roles global biogeochemical cycling reduction, oxidation accumulation formation.

Language: Английский

Citations

1
More Than Deoxygenation: Linking Iodate Reduction to Nitrogen, Iron, and Sulfur Chemistry in Reducing Regimes DOI Creative Commons
Natalya Evans, Emma Johnson,

Amanda Taing

et al.

Journal of Geophysical Research Oceans, Journal Year: 2024, Volume and Issue: 129(11)

Published: Nov. 1, 2024

Abstract A striking feature of Oxygen Deficient Zones (ODZs) on the eastern boundary Pacific Ocean are large subsurface plumes iodide. Throughout oceans, iodate is predominant and thermodynamically favored species dissolved iodine, but depleted within these plumes. The origin iodide mechanism reduction to remains unclear thought arise from a combination in situ inputs reducing shelf sediments. To distinguish between sources, we investigated iodine redox speciation along Oregon continental shelf. This upwelling system resembles ODZs exhibits episodic hypoxia, rather than persistently denitrifying water column. We observed elevated benthic layer overlying sediments, much smaller extent ODZs. There was no evidence offshore or increases total iodine. Results suggest that an anaerobic column dominated by denitrification, such as ODZs, required for reduction. However, re‐analysis data previous ODZ work suggests most occurs not column, also decoupled denitrification. underlying differences regimes have yet be resolved, could indicate role reduced sulfur if sulfate zone closer sediment‐water interface sediments Iodate simple function oxygen depletion, which has important implications its application paleoredox tracer.

Language: Английский

Citations

1
Characterizing the marine iodine cycle and its relationship to ocean deoxygenation in an Earth system model DOI Creative Commons
Keyi Cheng, Andy Ridgwell, Dalton Hardisty

et al.

Biogeosciences, Journal Year: 2024, Volume and Issue: 21(21), P. 4927 - 4949

Published: Nov. 13, 2024

Abstract. Iodine (I) abundance in marine carbonates (measured as an elemental ratio with calcium, I / Ca) is of broad interest a proxy for local/regional ocean redox. This connection arises because the speciation iodine seawater, balance between iodate (IO3-) and iodide (I−), sensitive to prevalence oxic vs. anoxic conditions. However, although Ca ratios are increasingly commonly being measured ancient carbonate samples, fully quantitative interpretation this requires availability mechanistic interpretative framework cycle that can account extent intensity deoxygenation past. Here we present evaluate representation cycling embedded Earth system model (“cGENIE”) against both modern paleo-observations. In framework, IO3- uptake release I− through biological pump, reduction ambient water column, re-oxidation IO3-. We develop test variety different plausible mechanisms oxidation transformation contrast projections updated compilation observed dissolved concentrations present-day ocean. By optimizing parameters controlling previously proposed involved cycling, find obtain matches gradients zonal surface distribution, depth profiles, oxygen-deficient zones (ODZs). also identify alternative, equally well performing which assume more explicit link environment – ambiguity highlights need process-based studies on cycling. Finally, help distinguish competing representations our ultimate motivation further ability reconstruct oxygenation geological past, conducted “plausibility tests” schemes available measurements made Cretaceous time substantially depleted oxygen compared hence strong model. Overall, simultaneous match achieve modeled observations, forward ratios, supports application modeling simulating interpret constrain redox evolution past oceans.

Language: Английский

Citations

1