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Lacroix EM, Aeppli M, Boye K, Brodie E, Fendorf S, Keiluweit M, Naughton HR, Noël V, Sihi D. Consider the Anoxic Microsite: Acknowledging and Appreciating Spatiotemporal Redox Heterogeneity in Soils and Sediments. ACS EARTH & SPACE CHEMISTRY 2023; 7:1592-1609. [PMID: 37753209 PMCID: PMC10519444 DOI: 10.1021/acsearthspacechem.3c00032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 05/07/2023] [Accepted: 07/21/2023] [Indexed: 09/28/2023]
Abstract
Reduction-oxidation (redox) reactions underlie essentially all biogeochemical cycles. Like most soil properties and processes, redox is spatiotemporally heterogeneous. However, unlike other soil features, redox heterogeneity has yet to be incorporated into mainstream conceptualizations of soil biogeochemistry. Anoxic microsites, the defining feature of redox heterogeneity in bulk oxic soils and sediments, are zones of oxygen depletion in otherwise oxic environments. In this review, we suggest that anoxic microsites represent a critical component of soil function and that appreciating anoxic microsites promises to advance our understanding of soil and sediment biogeochemistry. In sections 1 and 2, we define anoxic microsites and highlight their dynamic properties, specifically anoxic microsite distribution, redox gradient magnitude, and temporality. In section 3, we describe the influence of anoxic microsites on several key elemental cycles, organic carbon, nitrogen, iron, manganese, and sulfur. In section 4, we evaluate methods for identifying and characterizing anoxic microsites, and in section 5, we highlight past and current approaches to modeling anoxic microsites. Finally, in section 6, we suggest steps for incorporating anoxic microsites and redox heterogeneities more broadly into our understanding of soils and sediments.
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Affiliation(s)
- Emily M. Lacroix
- Institut
des Dynamiques de la Surface Terrestre (IDYST), Université de Lausanne, 1015 Lausanne, Switzerland
- Department
of Earth System Science, Stanford University, Stanford, California 94305, United States
| | - Meret Aeppli
- Institut
d’ingénierie de l’environnement (IIE), École Polytechnique Fédérale
de Lausanne, 1015 Lausanne, Switzerland
| | - Kristin Boye
- Environmental
Geochemistry Group, SLAC National Accelerator
Laboratory, Menlo Park, California 94025, United States
| | - Eoin Brodie
- Lawrence
Berkeley Laboratory, Earth and Environmental
Sciences Area, Berkeley, California 94720, United States
| | - Scott Fendorf
- Department
of Earth System Science, Stanford University, Stanford, California 94305, United States
| | - Marco Keiluweit
- Institut
des Dynamiques de la Surface Terrestre (IDYST), Université de Lausanne, 1015 Lausanne, Switzerland
| | - Hannah R. Naughton
- Lawrence
Berkeley Laboratory, Earth and Environmental
Sciences Area, Berkeley, California 94720, United States
| | - Vincent Noël
- Environmental
Geochemistry Group, SLAC National Accelerator
Laboratory, Menlo Park, California 94025, United States
| | - Debjani Sihi
- Department
of Environmental Sciences, Emory University, Atlanta, Georgia 30322, United States
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Meredith LK, Tfaily MM. Capturing the microbial volatilome: an oft overlooked 'ome'. Trends Microbiol 2022; 30:622-631. [PMID: 35039213 DOI: 10.1016/j.tim.2021.12.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 12/03/2021] [Accepted: 12/08/2021] [Indexed: 11/26/2022]
Abstract
Among the diverse metabolites produced by microbial communities, some are volatile. Volatile organic compounds (VOCs) are vigorously cycled by microbes as metabolic substrates and products and as signaling molecules. Yet, current microbial metabolomic studies predominantly focus on nonvolatile metabolites and overlook VOCs, which therefore represent a missing component of the metabolome. Advances in VOC detection now allow simultaneous observation of the numerous VOCs constituting the 'volatilome' of microbial systems. We present a roadmap for integrating and advancing VOC and other 'omics approaches and highlight the potential for realtime VOC measurements to help overcome limitations in discrete 'omics sampling. Including volatile metabolites in metabolomics, both conceptually and in practice, will build a more comprehensive understanding of microbial processes across ecological communities.
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Affiliation(s)
- Laura K Meredith
- School of Natural Resources and the Environment, University of Arizona, Tucson, AZ, USA; BIO5 Institute, University of Arizona, Tucson, AZ, USA.
| | - Malak M Tfaily
- BIO5 Institute, University of Arizona, Tucson, AZ, USA; Department of Environmental Science, University of Arizona, Tucson, AZ, USA.
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