Taphonomic experiments resolve controls on the preservation of melanosomes and keratinous tissues in feathers DOI Creative Commons
Tiffany S. Slater, Maria E. McNamara, Patrick J. Orr

et al.

Palaeontology, Journal Year: 2019, Volume and Issue: 63(1), P. 103 - 115

Published: Sept. 19, 2019

Fossils are a key source of data on the evolution feather structure and function through deep time, but their ability to resolve macroevolutionary questions is compromised by an incomplete understanding taphonomy. Critically, relative preservation potential two components, melanosomes keratinous tissue, not fully resolved. Recent studies suggesting that preferentially preserved conflict with observations preserve in fossil feathers as external moulds organic matrix. To date, there no model explain latter mode melanosome preservation. We addressed these issues degrading systematic taphonomic experiments incorporating decay, maturation oxidation isolation combination. Our results reveal production mouldic requires interactions oxidant most likely occur prior substantial maturation. This constrains conditions under which be fossilized. our also confirm structures have higher than range diagenetic conditions, supporting hitherto controversial hypotheses can retain degraded structures.

Language: Английский

Dynamic interactions at the mineral–organic matter interface DOI
Markus Kleber, Ian C. Bourg, Elizabeth K. Coward

et al.

Nature Reviews Earth & Environment, Journal Year: 2021, Volume and Issue: 2(6), P. 402 - 421

Published: May 11, 2021

Language: Английский

Citations

657
A Critical Review on the Multiple Roles of Manganese in Stabilizing and Destabilizing Soil Organic Matter DOI Creative Commons
Hui Li, Fernanda Santos,

Kristen Butler

et al.

Environmental Science & Technology, Journal Year: 2021, Volume and Issue: 55(18), P. 12136 - 12152

Published: Sept. 1, 2021

Manganese (Mn) is a biologically important and redox-active metal that may exert poorly recognized control on carbon (C) cycling in terrestrial ecosystems. influences ecosystem C dynamics by mediating biochemical pathways include photosynthesis, serving as reactive intermediate the breakdown of organic molecules, binding and/or oxidizing molecules through organo-mineral associations. However, potential for Mn to influence storage remains unresolved. Although substantial research has demonstrated ability Fe- Al-oxides stabilize matter, there scarcity similar information regarding Mn-oxides. Furthermore, Mn-mediated reactions regulate litter decomposition pathways, but these processes are constrained across diverse Here, we discuss ecological roles environments synthesize existing knowledge multiple which biogeochemical intersect. We demonstrate high degrade abiotic microbially mediated oxidation at least temporarily, outline priorities needed advance understanding Mn-C interactions, highlighting gaps address key uncertainties soil predictions.

Language: Английский

Citations

187
Fenton chemistry and reactive oxygen species in soil: Abiotic mechanisms of biotic processes, controls and consequences for carbon and nutrient cycling DOI
Guanghui Yu, Yakov Kuzyakov

Earth-Science Reviews, Journal Year: 2021, Volume and Issue: 214, P. 103525 - 103525

Published: Jan. 17, 2021

Language: Английский

Citations

171
Coupled Manganese Redox Cycling and Organic Carbon Degradation on Mineral Surfaces DOI
Dong Ma, Juan Wu, Peng Yang

et al.

Environmental Science & Technology, Journal Year: 2020, Volume and Issue: 54(14), P. 8801 - 8810

Published: June 17, 2020

Minerals, natural organic matter (NOM), and divalent manganese (Mn(II)) often coexist in suboxic/oxic environment. Multiple adsorption oxidation processes occur this ternary system, which are coupled to affect the fate of both OM Mn therein alter their chemical reactivity toward metals other pollutants. However, details about coupling poorly known although much has been gained for binary systems. We determined mutual influence surface-catalyzed Mn(II) humic acid (HA) a Fe(III) oxide (goethite)-HA-Mn(II) system at pH 5-8. The presence substantially increased HA whereas greatly impaired extent rate by O2 on goethite surfaces. impacts were more pronounced higher pH. produced β-MnOOH, γ-MnOOH, Mn3O4 turn oxidized HA, producing small acids. markedly altered composition products inhibiting formation β-MnOOH while favoring production γ-MnOOH adsorbed HA-mineral assemblage. Nonconducting γ-Al2O3 exhibited similar but weaker effects than semiconducting above processes. Our results suggest that Mn-oxidizing microorganisms, mineral surfaces can drive redox cycle with NOM oxidative degradation under circumneutral/alkaline conditions.

Language: Английский

Citations

87
Enzymes, Manganese, or Iron? Drivers of Oxidative Organic Matter Decomposition in Soils DOI
Morris E. Jones,

Rachelle LaCroix,

Jacob Zeigler

et al.

Environmental Science & Technology, Journal Year: 2020, Volume and Issue: 54(21), P. 14114 - 14123

Published: Oct. 23, 2020

Oxidative decomposition of soil organic matter determines the proportion carbon that is either stored or emitted to atmosphere as CO2. Full conversion CO2 requires oxidative mechanisms depolymerize complex molecules into smaller, soluble monomers can be respired by microbes. Current models attribute depolymerization largely activity extracellular enzymes. Here we show reactive manganese (Mn) and iron (Fe) intermediates, rather than other measured characteristics, best predict in temperate forest soils. Combining bioassays, spectroscopy, wet-chemical analysis, found surface litters was most significantly correlated abundance Mn(III) species. In contrast, underlying mineral soils Fe(II/III) Positive controls showed both species are equally potent generating activity, but imply conventional bioassays have a systematic bias toward Fe. Combined, our results highlight coupled biotic-abiotic nature mechanisms, with Mn-mediated oxidation dominating within Mn-rich Fe-mediated Fe-rich These findings suggest microbes rely on different strategies depending relative availability Fe Mn given environment.

Language: Английский

Citations

87
Geochemical Stability of Dissolved Mn(III) in the Presence of Pyrophosphate as a Model Ligand: Complexation and Disproportionation DOI

Ao Qian,

Wen Zhang, Cheng Shi

et al.

Environmental Science & Technology, Journal Year: 2019, Volume and Issue: 53(10), P. 5768 - 5777

Published: April 11, 2019

Dissolved Mn(III) species have recently been recognized as a significant form of Mn in redox transition zones, but their speciation, stability, and reactivity are poorly understood. Besides acting the intermediate for chemistry, can undergo disproportionation producing insoluble oxides aqueous Mn(II). Using pyrophosphate(PP) model ligand, we evaluated thermodynamic kinetic stability complexes. They were stable at circumneutral pH prone to (partial) acidic or basic pH. With an initial lag phase, kinetics Mn(III)–PP was autocatalytic with produced promoting disproportionation. X-ray diffraction average oxidation state indicated that solid products not pure Mn(IV) mixture triclinic birnessite δ-MnO2. Addition synthetic analogs precipitates eliminated confirming catalytic roles. Thermodynamic calculations adequately predicted regime Mn(III)–PP. The present results refined constant Mn(PP)25– formation, which allows consistent quantitative prediction equilibrium speciation Mn(III)–Mn(II)–birnessite PP. A simple robust model, incorporated constraints, rate law, verified reaction stoichiometry, successfully simulated all data.

Language: Английский

Citations

80
Oxidative transformation of emerging organic contaminants by aqueous permanganate: Kinetics, products, toxicity changes, and effects of manganese products DOI
Juan Li,

Su–Yan Pang,

Zhen Wang

et al.

Water Research, Journal Year: 2021, Volume and Issue: 203, P. 117513 - 117513

Published: Aug. 2, 2021

Language: Английский

Citations

67
Consider the Anoxic Microsite: Acknowledging and Appreciating Spatiotemporal Redox Heterogeneity in Soils and Sediments DOI Creative Commons
Emily M. Lacroix, Meret Aeppli, Kristin Boye

et al.

ACS Earth and Space Chemistry, Journal Year: 2023, Volume and Issue: 7(9), P. 1592 - 1609

Published: Aug. 23, 2023

Reduction-oxidation (redox) reactions underlie essentially all biogeochemical cycles. Like most soil properties and processes, redox is spatiotemporally heterogeneous. However, unlike other features, heterogeneity has yet to be incorporated into mainstream conceptualizations of biogeochemistry. Anoxic microsites, the defining feature in bulk oxic soils sediments, are zones oxygen depletion otherwise environments. In this review, we suggest that anoxic microsites represent a critical component function appreciating promises advance our understanding sediment sections 1 2, define highlight their dynamic properties, specifically microsite distribution, gradient magnitude, temporality. section 3, describe influence on several key elemental cycles, organic carbon, nitrogen, iron, manganese, sulfur. 4, evaluate methods for identifying characterizing 5, past current approaches modeling microsites. Finally, 6, steps incorporating heterogeneities more broadly sediments.

Language: Английский

Citations

40
Mn(III)-mediated bisphenol a degradation: Mechanisms and products DOI
Yanchen Sun, Chao Wang, Amanda L. May

et al.

Water Research, Journal Year: 2023, Volume and Issue: 235, P. 119787 - 119787

Published: Feb. 23, 2023

Language: Английский

Citations

33
Oxygen Limitation Accelerates Regeneration of Active Sites on a MnO2 Surface: Promoting Transformation of Organic Matter and Carbon Preservation DOI
Zhiqiang Wang, Hanzhong Jia, H. Zhao

et al.

Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(13), P. 9806 - 9815

Published: June 20, 2022

Birnessite (δ-MnO2) is a layered manganese oxide widely present in the environment and actively participates transformation of natural organic matter (NOM) biogeochemical processes. However, effect oxygen on dynamic interface processes NOM δ-MnO2 remains unclear. This study systematically investigated interactions between fulvic acid (FA) under both aerobic anaerobic conditions. FA was transformed by via direct electron transfer generated reactive species (ROS). During 32-day reaction, 79.8% total carbon (TOC) solution removed conditions, unexpectedly higher than that conditions (69.8%), suggesting limitation more conducive to oxidative δ-MnO2. The vacancies (OV) surface were exposed thus promoting adsorption as well regeneration active sites. Additionally, reaction with weakened strongly bonded lattice (Olatt), released Olatt an important source ROS. Interestingly, part (OC) preserved forming MnCO3, which might be novel mechanism for preservation. These findings contribute improved understanding MnO2 provide new insights into effects cycling preservation OC.

Language: Английский

Citations

31