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Paul KM, van Helmond NAGM, Slomp CP, Jilbert T. Trace metals in coastal marine sediments: Natural and anthropogenic sources, correlation matrices, and proxy potentials. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 951:175789. [PMID: 39197767 DOI: 10.1016/j.scitotenv.2024.175789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 08/02/2024] [Accepted: 08/23/2024] [Indexed: 09/01/2024]
Abstract
Rapidly spreading industrialization since the 19th century has led to a drastic increase in trace metal deposition in coastal sediments. Provided that these trace metals have remained relatively immobile after deposition, their sedimentary enrichments can serve as records of local-regional pollution histories. Factors controlling this proxy potential include trace metal geochemistry (carrier-, and host phase affinity), and depositional environmental factors (redox variability, particulate shuttling, organic matter loading, bathymetry). Yet, the relative importance and interactions between these controls are still poorly understood, hampering the reliable use of trace metal-based environmental proxies. By summarizing nine site-specific correlation matrices of 16 metal (loid) s (Pb, Cd, Cu, Zn, Sb, Sn, Ni, As, Tl, V, Mo, U, Re, Fe, Mn, Al), total organic C, and S contents in short sediment cores into a single meta-matrix, we test a novel approach for quickly detecting common and contrasting trace metal enrichment patterns across different study locations. Our meta-matrix shows two trace metal groups, within which positive correlations of e.g., Pb, Cd, Zn, Cu, Sb suggest a primary "anthropogenically sourced" (group I) control, whereas known "redox-sensitive" (group II) trace metals (Mo, U, Re) are characterized by fewer positive correlations. However, some group I metals (Cd, Zn, Cu, Sb) also covary with group II metals, inferring that redox variability may obscure primary anthropogenic signals; Sb even shows advantages over Mo and U under oxic conditions. As a more robust pollution indicator we identified Pb; yet for reconstructing historical Pb atmospheric pollution signals (1970s Pb peak), it is crucial to consider the distance from shore. In near-shore environments, local (fluvial) pollution signals may overprint large-scale (atmospheric) signals. Our findings demonstrate that combining site-specific sedimentary correlation and distribution patterns with a meta-matrix considerably aids the understanding of trace metal sequestration in different coastal sedimentary environments, which thereby improves trace metal proxy reliability.
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Affiliation(s)
- K Mareike Paul
- Environmental Geochemistry Group, Department of Geography and Geosciences, Faculty of Science, University of Helsinki, Helsinki, P.O 64 (Gustaf Hällströmin katu 2), FI-00014, Finland.
| | - Niels A G M van Helmond
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht 3584 CB, the Netherlands; Radboud Institute for Biological and Environmental Sciences, Faculty of Science, Radboud University, Nijmegen 6525 AJ, the Netherlands
| | - Caroline P Slomp
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht 3584 CB, the Netherlands; Radboud Institute for Biological and Environmental Sciences, Faculty of Science, Radboud University, Nijmegen 6525 AJ, the Netherlands
| | - Tom Jilbert
- Environmental Geochemistry Group, Department of Geography and Geosciences, Faculty of Science, University of Helsinki, Helsinki, P.O 64 (Gustaf Hällströmin katu 2), FI-00014, Finland
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2
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Chen Y, Dong L, Sui W, Niu M, Cui X, Hinrichs KU, Wang F. Cycling and persistence of iron-bound organic carbon in subseafloor sediments. Nat Commun 2024; 15:6370. [PMID: 39075044 PMCID: PMC11286938 DOI: 10.1038/s41467-024-50578-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 07/16/2024] [Indexed: 07/31/2024] Open
Abstract
Reactive iron (FeR) serves as an important sink of organic carbon (OC) in marine surface sediments, which preserves approximately 20% of total OC (TOC) as reactive iron-bound OC (FeR-OC). However, the fate of FeR-OC in subseafloor sediments and its availability to microorganisms, remain undetermined. Here, we reconstructed continuous FeR-OC records in two sediment cores of the northern South China Sea encompassing the suboxic to methanic biogeochemical zones and reaching a maximum age of ~100 kyr. The downcore FeR-OC contributes a relatively stable proportion of 13.3 ± 3.2% to TOC. However, distinctly lower values of less than 5% of TOC, accompanied by notable 13C depletion of FeR-OC, are observed in the sulfate-methane transition zone (SMTZ). FeR-OC is suggested to be remobilized by microbially mediated reductive dissolution of FeR and subsequently remineralized, the flux of which is 18-30% of the methane consumption in the SMTZ. The global reservoir of FeR-OC in microbially active Quaternary marine sediments could be 19-46 times the size of the atmospheric carbon pool. Thus, the FeR-OC pool may support subseafloor microorganisms and contribute to regulating Earth's carbon cycle.
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Affiliation(s)
- Yunru Chen
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
- MARUM-Center for Marine Environmental Sciences, University of Bremen, D-28359, Bremen, Germany
| | - Liang Dong
- Key Laboratory of Polar Ecosystem and Climate Change, Ministry of Education, and School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Weikang Sui
- Key Laboratory of Polar Ecosystem and Climate Change, Ministry of Education, and School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Mingyang Niu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xingqian Cui
- Key Laboratory of Polar Ecosystem and Climate Change, Ministry of Education, and School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Kai-Uwe Hinrichs
- MARUM-Center for Marine Environmental Sciences, University of Bremen, D-28359, Bremen, Germany
- Faculty of Geosciences, University of Bremen, D-28359, Bremen, Germany
| | - Fengping Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
- Key Laboratory of Polar Ecosystem and Climate Change, Ministry of Education, and School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200240, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, China.
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3
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Xiao B, Guo D, Zhao Z, Xiong S, Feng M, Zhao Z, Li S. Elemental Geochemical Characteristics of Shales from Wufeng-Longmaxi Formations in the Southern Margin of the Qinling Orogenic Belt, China: Implications for Depositional Controls on Organic Matter. ACS OMEGA 2024; 9:31488-31507. [PMID: 39072083 PMCID: PMC11270573 DOI: 10.1021/acsomega.4c01129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 05/12/2024] [Accepted: 07/05/2024] [Indexed: 07/30/2024]
Abstract
The tectonic background and sedimentary environment during the transition period from the Ordovician to Silurian have been widely studied by many scholars. This study focuses on the Upper Ordovician Wufeng Formation and Lower Silurian Longmaxi Formation in the Bajiaokou profile at the southern margin of the Qinling Orogenic Belt in southern China. In order to study the aggregation mechanism of organic matter, geochemical proxies were proposed, including redox proxies (V, V/Al, U, U/Al, Mo, and Mo/Al), paleoproductivity proxies (P, P/Ti, Ba, Ba/Al, and SiXS), paleoclimate proxies (CIA), and terrigenous flux proxies (Al, Zr, and Zr/Al). In addition, Al-Co[EF] × Mn[EF] is used to provide information on paleoenvironmental parameters such as watermass restriction conditions. The redox proxies show that the Wufeng-Longmaxi shale is mainly accumulated under oxic-dysoxic conditions. During the shale deposition period of Wufeng-Longmaxi formations, the marine surface primary productivity in the southern Qinling area is generally low to moderate. The paleoclimate proxies show that from the Late Ordovician to the Early Silurian the southern Qinling area generally had a warm and humid climate. The upwelling current is widely developed in the northern margin of the Sichuan Basin and the southern margin of the Qinling area. Although the upwelling current was highly developed during the deposition of the Wufeng Formation in the Bajiaokou profile, the concentrated accumulation of a large amount of volcanic ash resulted in the low primary productivity of the ocean. During the sedimentary period of the Longmaxi Formation in the Bajiaokou profile, the development of seasonal upwelling currents and a small amount of volcanic ash supply increased the primary productivity to moderate, which provided a good material basis for the enrichment of organic matter, but the high detritus flux and the water body condition of oxic-dysoxic resulted in the slight enrichment of organic matter.
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Affiliation(s)
- Bin Xiao
- College
of Mining, Liaoning Technical University, Fuxin 123000, China
| | - Dongxu Guo
- College
of Mining, Liaoning Technical University, Fuxin 123000, China
| | - Zhongying Zhao
- PetroChina
Research Institute of Petroleum Exploration & Development, Beijing 100083, China
| | - Shuzhen Xiong
- College
of Environmental Science and Engineering, Liaoning Technical University, Fuxin 123000, China
| | - Mingfei Feng
- College
of Mining, Liaoning Technical University, Fuxin 123000, China
| | - Zhonghai Zhao
- College
of Mining, Liaoning Technical University, Fuxin 123000, China
| | - Sheng Li
- Liaoning
Geology Engineering Vocational College, Dandong 118000, China
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4
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Dalcin Martins P, de Monlevad JPC, Echeveste Medrano MJ, Lenstra WK, Wallenius AJ, Hermans M, Slomp CP, Welte CU, Jetten MSM, van Helmond NAGM. Sulfide Toxicity as Key Control on Anaerobic Oxidation of Methane in Eutrophic Coastal Sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:11421-11435. [PMID: 38888209 PMCID: PMC11223495 DOI: 10.1021/acs.est.3c10418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 06/07/2024] [Accepted: 06/10/2024] [Indexed: 06/20/2024]
Abstract
Coastal zones account for 75% of marine methane emissions, despite covering only 15% of the ocean surface area. In these ecosystems, the tight balance between methane production and oxidation in sediments prevents most methane from escaping into seawater. However, anthropogenic activities could disrupt this balance, leading to an increased methane escape from coastal sediments. To quantify and unravel potential mechanisms underlying this disruption, we used a suite of biogeochemical and microbiological analyses to investigate the impact of anthropogenically induced redox shifts on methane cycling in sediments from three sites with contrasting bottom water redox conditions (oxic-hypoxic-euxinic) in the eutrophic Stockholm Archipelago. Our results indicate that the methane production potential increased under hypoxia and euxinia, while anaerobic oxidation of methane was disrupted under euxinia. Experimental, genomic, and biogeochemical data suggest that the virtual disappearance of methane-oxidizing archaea at the euxinic site occurred due to sulfide toxicity. This could explain a near 7-fold increase in the extent of escape of benthic methane at the euxinic site relative to the hypoxic one. In conclusion, these insights reveal how the development of euxinia could disrupt the coastal methane biofilter, potentially leading to increased methane emissions from coastal zones.
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Affiliation(s)
- Paula Dalcin Martins
- Department
of Microbiology, Radboud Institute for Biological and Environmental
Sciences, Radboud University, Nijmegen 6525 AJ, The Netherlands
- Department
of Ecosystem and Landscape Dynamics, Institute for Biodiversity and
Ecosystem Dynamics (IBED), University of
Amsterdam, Amsterdam 1098 XH, The Netherlands
| | - João P.
R. C. de Monlevad
- Department
of Microbiology, Radboud Institute for Biological and Environmental
Sciences, Radboud University, Nijmegen 6525 AJ, The Netherlands
| | - Maider J. Echeveste Medrano
- Department
of Microbiology, Radboud Institute for Biological and Environmental
Sciences, Radboud University, Nijmegen 6525 AJ, The Netherlands
| | - Wytze Klaas Lenstra
- Department
of Microbiology, Radboud Institute for Biological and Environmental
Sciences, Radboud University, Nijmegen 6525 AJ, The Netherlands
- Department
of Earth Sciences—Geochemistry, Utrecht
University, Utrecht 3584 CB, The Netherlands
| | - Anna Julia Wallenius
- Department
of Microbiology, Radboud Institute for Biological and Environmental
Sciences, Radboud University, Nijmegen 6525 AJ, The Netherlands
| | - Martijn Hermans
- Department
of Earth Sciences—Geochemistry, Utrecht
University, Utrecht 3584 CB, The Netherlands
- Baltic
Sea Centre, Stockholm University, Stockholm 114 18, Sweden
| | - Caroline P. Slomp
- Department
of Microbiology, Radboud Institute for Biological and Environmental
Sciences, Radboud University, Nijmegen 6525 AJ, The Netherlands
- Department
of Earth Sciences—Geochemistry, Utrecht
University, Utrecht 3584 CB, The Netherlands
| | - Cornelia Ulrike Welte
- Department
of Microbiology, Radboud Institute for Biological and Environmental
Sciences, Radboud University, Nijmegen 6525 AJ, The Netherlands
| | - Mike S. M. Jetten
- Department
of Microbiology, Radboud Institute for Biological and Environmental
Sciences, Radboud University, Nijmegen 6525 AJ, The Netherlands
| | - Niels A. G. M. van Helmond
- Department
of Microbiology, Radboud Institute for Biological and Environmental
Sciences, Radboud University, Nijmegen 6525 AJ, The Netherlands
- Department
of Earth Sciences—Geochemistry, Utrecht
University, Utrecht 3584 CB, The Netherlands
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5
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Stenow R, Robertson EK, Kourtchenko O, Whitehouse MJ, Pinder MIM, Benvenuto G, Töpel M, Godhe A, Ploug H. Resting cells of Skeletonema marinoi assimilate organic compounds and respire by dissimilatory nitrate reduction to ammonium in dark, anoxic conditions. Environ Microbiol 2024; 26:e16625. [PMID: 38653479 DOI: 10.1111/1462-2920.16625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 04/05/2024] [Indexed: 04/25/2024]
Abstract
Diatoms can survive long periods in dark, anoxic sediments by forming resting spores or resting cells. These have been considered dormant until recently when resting cells of Skeletonema marinoi were shown to assimilate nitrate and ammonium from the ambient environment in dark, anoxic conditions. Here, we show that resting cells of S. marinoi can also perform dissimilatory nitrate reduction to ammonium (DNRA), in dark, anoxic conditions. Transmission electron microscope analyses showed that chloroplasts were compacted, and few large mitochondria had visible cristae within resting cells. Using secondary ion mass spectrometry and isotope ratio mass spectrometry combined with stable isotopic tracers, we measured assimilatory and dissimilatory processes carried out by resting cells of S. marinoi under dark, anoxic conditions. Nitrate was both respired by DNRA and assimilated into biomass by resting cells. Cells assimilated nitrogen from urea and carbon from acetate, both of which are sources of dissolved organic matter produced in sediments. Carbon and nitrogen assimilation rates corresponded to turnover rates of cellular carbon and nitrogen content ranging between 469 and 10,000 years. Hence, diatom resting cells can sustain their cells in dark, anoxic sediments by slowly assimilating and respiring substrates from the ambient environment.
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Affiliation(s)
- Rickard Stenow
- Department of Marine Sciences, University of Gothenburg, Gothenburg, SE, Sweden
| | | | - Olga Kourtchenko
- Department of Marine Sciences, University of Gothenburg, Gothenburg, SE, Sweden
| | | | - Matthew I M Pinder
- Department of Marine Sciences, University of Gothenburg, Gothenburg, SE, Sweden
| | | | - Mats Töpel
- Department of Marine Sciences, University of Gothenburg, Gothenburg, SE, Sweden
- IVL-Swedish Environmental Research Institute, Gothenburg, SE, Sweden
| | - Anna Godhe
- Department of Marine Sciences, University of Gothenburg, Gothenburg, SE, Sweden
| | - Helle Ploug
- Department of Marine Sciences, University of Gothenburg, Gothenburg, SE, Sweden
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6
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Yang N, Lv Y, Ji M, Wu S, Zhang Y. High hydrostatic pressure stimulates microbial nitrate reduction in hadal trench sediments under oxic conditions. Nat Commun 2024; 15:2473. [PMID: 38503798 PMCID: PMC10951307 DOI: 10.1038/s41467-024-46897-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 03/13/2024] [Indexed: 03/21/2024] Open
Abstract
Hadal trenches are extreme environments situated over 6000 m below sea surface, where enormous hydrostatic pressure affects the biochemical cycling of elements. Recent studies have indicated that hadal trenches may represent a previously overlooked source of fixed nitrogen loss; however, the mechanisms and role of hydrostatic pressure in this process are still being debated. To this end, we investigate the effects of hydrostatic pressure (0.1 to 115 MPa) on the chemical profile, microbial community structure and functions of surface sediments from the Mariana Trench using a Deep Ocean Experimental Simulator supplied with nitrate and oxygen. We observe enhanced denitrification activity at high hydrostatic pressure under oxic conditions, while the anaerobic ammonium oxidation - a previously recognized dominant nitrogen loss pathway - is not detected. Additionally, we further confirm the simultaneous occurrence of nitrate reduction and aerobic respiration using a metatranscriptomic dataset from in situ RNA-fixed sediments in the Mariana Trench. Taken together, our findings demonstrate that hydrostatic pressure can influence microbial contributions to nitrogen cycling and that the hadal trenches are a potential nitrogen loss hotspot. Knowledge of the influence of hydrostatic pressure on anaerobic processes in oxygenated surface sediments can greatly broaden our understanding of element cycling in hadal trenches.
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Affiliation(s)
- Na Yang
- School of Oceanography; Shanghai Key Laboratory of Polar Life and Environment Sciences; MOE Key Laboratory of Polar Ecosystem and Climate Change, Shanghai Jiao Tong University, Shanghai, China
| | - Yongxin Lv
- School of Oceanography; Shanghai Key Laboratory of Polar Life and Environment Sciences; MOE Key Laboratory of Polar Ecosystem and Climate Change, Shanghai Jiao Tong University, Shanghai, China
| | - Mukan Ji
- Center for Pan-third Pole Environment, Lanzhou University, Lanzhou, China
| | - Shiguo Wu
- Institute of Deep-sea Science and Engineering, Chinese Academy of Science, Sanya, China
| | - Yu Zhang
- School of Oceanography; Shanghai Key Laboratory of Polar Life and Environment Sciences; MOE Key Laboratory of Polar Ecosystem and Climate Change, Shanghai Jiao Tong University, Shanghai, China.
- Laboratory for Polar Science, Polar Research Institute of China, Ministry of Natural Resources, Shanghai, China.
- Yazhou Bay Institute of Deepsea Sci-Tech, Shanghai Jiao Tong University, Sanya, China.
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7
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Schauberger C, Thamdrup B, Lemonnier C, Trouche B, Poulain J, Wincker P, Arnaud-Haond S, Glud RN, Maignien L. Metagenome-assembled genomes of deep-sea sediments: changes in microbial functional potential lag behind redox transitions. ISME COMMUNICATIONS 2024; 4:ycad005. [PMID: 38282644 PMCID: PMC10809760 DOI: 10.1093/ismeco/ycad005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 01/30/2024]
Abstract
Hadal sediments are hotspots of microbial activity in the deep sea and exhibit strong biogeochemical gradients. But although these gradients are widely assumed to exert selective forces on hadal microbial communities, the actual relationship between biogeochemistry, functional traits, and microbial community structure remains poorly understood. We tested whether the biogeochemical conditions in hadal sediments select for microbes based on their genomic capacity for respiration and carbohydrate utilization via a metagenomic analysis of over 153 samples from the Atacama Trench region (max. depth = 8085 m). The obtained 1357 non-redundant microbial genomes were affiliated with about one-third of all known microbial phyla, with more than half belonging to unknown genera. This indicated that the capability to withstand extreme hydrostatic pressure is a phylogenetically widespread trait and that hadal sediments are inhabited by diverse microbial lineages. Although community composition changed gradually over sediment depth, these changes were not driven by selection for respiratory or carbohydrate degradation capability in the oxic and nitrogenous zones, except in the case of anammox bacteria and nitrifying archaea. However, selection based on respiration and carbohydrate degradation capacity did structure the communities of the ferruginous zone, where aerobic and nitrogen respiring microbes declined exponentially (half-life = 125-419 years) and were replaced by subsurface communities. These results highlight a delayed response of microbial community composition to selective pressure imposed by redox zonation and indicated that gradual changes in microbial composition are shaped by the high-resilience and slow growth of microbes in the seafloor.
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Affiliation(s)
- Clemens Schauberger
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
| | - Bo Thamdrup
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
| | - Clarisse Lemonnier
- Microbiology of Extreme Environments Laboratory, CNRS, IFREMER, Univ Brest, F-29280 Plouzané, France
| | - Blandine Trouche
- Microbiology of Extreme Environments Laboratory, CNRS, IFREMER, Univ Brest, F-29280 Plouzané, France
| | - Julie Poulain
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS,University of Évry, Université Paris-Saclay, 91057 Evry, France
| | - Patrick Wincker
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS,University of Évry, Université Paris-Saclay, 91057 Evry, France
| | - Sophie Arnaud-Haond
- MARBEC, CNRS, IRD, Institut Français de Recherche pour L'Exploitation de la Mer, Univ Montpellier, 34200 Sète, France
| | - Ronnie N Glud
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
- Department of Ocean and Environmental Sciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan
| | - Lois Maignien
- Microbiology of Extreme Environments Laboratory, CNRS, IFREMER, Univ Brest, F-29280 Plouzané, France
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8
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Jaussi M, Jørgensen BB, Kjeldsen KU, Lomstein BA, Pearce C, Seidenkantz MS, Røy H. Cell-specific rates of sulfate reduction and fermentation in the sub-seafloor biosphere. Front Microbiol 2023; 14:1198664. [PMID: 37555068 PMCID: PMC10405931 DOI: 10.3389/fmicb.2023.1198664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 07/05/2023] [Indexed: 08/10/2023] Open
Abstract
Microorganisms in subsurface sediments live from recalcitrant organic matter deposited thousands or millions of years ago. Their catabolic activities are low, but the deep biosphere is of global importance due to its volume. The stability of deeply buried sediments provides a natural laboratory where prokaryotic communities that live in steady state with their environments can be studied over long time scales. We tested if a balance is established between the flow of energy, the microbial community size, and the basal power requirement needed to maintain cells in sediments buried meters below the sea floor. We measured rates of carbon oxidation by sulfate reduction and counted the microbial cells throughout ten carefully selected sediment cores with ages from years to millions of years. The rates of carbon oxidation were converted to power (J s-1 i.e., Watt) using the Gibbs free energy of the anaerobic oxidation of complex organic carbon. We separated energy dissipation by fermentation from sulfate reduction. Similarly, we separated the community into sulfate reducers and non-sulfate reducers based on the dsrB gene, so that sulfate reduction could be related to sulfate reducers. We found that the per-cell sulfate reduction rate was stable near 10-2 fmol C cell-1 day-1 right below the zone of bioturbation and did not decrease with increasing depth and sediment age. The corresponding power dissipation rate was 10-17 W sulfate-reducing cell-1. The cell-specific power dissipation of sulfate reducers in old sediments was similar to the slowest growing anaerobic cultures. The energy from mineralization of organic matter that was not dissipated by sulfate reduction was distributed evenly to all cells that did not possess the dsrB gene, i.e., cells operationally defined as fermenting. In contrast to sulfate reducers, the fermenting cells had decreasing catabolism as the sediment aged. A vast difference in power requirement between fermenters and sulfate reducers caused the microbial community in old sediments to consist of a minute fraction of sulfate reducers and a vast majority of fermenters.
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Affiliation(s)
- Marion Jaussi
- Department of Biology, Aarhus University, Aarhus, Denmark
| | | | | | | | - Christof Pearce
- Department of Geoscience, Aarhus University, Aarhus, Denmark
| | | | - Hans Røy
- Department of Biology, Aarhus University, Aarhus, Denmark
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9
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Lin X, Zhang C, Xie W. Deterministic processes dominate archaeal community assembly from the Pearl River to the northern South China Sea. Front Microbiol 2023; 14:1185436. [PMID: 37426005 PMCID: PMC10324572 DOI: 10.3389/fmicb.2023.1185436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 06/07/2023] [Indexed: 07/11/2023] Open
Abstract
Archaea play a significant role in the biogeochemical cycling of nutrients in estuaries. However, comprehensive researches about their assembly processes remain notably insufficient. In this study, we systematically examined archaeal community dynamics distinguished between low-salinity and high-salinity groups in water and surface sediments over a 600-kilometer range from the upper Pearl River (PR) to the northern South China Sea (NSCS). Neutral community model analysis together with null model analysis showed that their C-score values were greater than 2, suggesting that deterministic processes could dominate the assembly of those planktonic or benthic archaeal communities at both the low-salinity and high-salinity sites. And deterministic processes contributed more in the low-salinity than high-salinity environments from the PR to the NSCS. Furthermore, through the co-occurrence network analysis, we found that the archaeal communities in the low-salinity groups possessed closer interactions and higher proportions of negative interactions than those in the high-salinity groups, which might be due to the larger environmental heterogeneities reflected by the nutrient concentrations of those low-salinity samples. Collectively, our work systematically investigated the composition and co-occurrence networks of archaeal communities in water as well as sediments from the PR to the NSCS, yielding new insights into the estuary's archaeal community assembly mechanisms.
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Affiliation(s)
- Xizheng Lin
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Zhuhai, China
| | - Chuanlun Zhang
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- Shenzhen Key Laboratory of Marine Archaea Geo-Omics, Department of Ocean Science & Engineering, Southern University of Science and Technology, Shenzhen, China
- Shanghai Sheshan National Geophysical Observatory, Shanghai Earthquake Agency, Shanghai, China
| | - Wei Xie
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Zhuhai, China
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10
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Baloza M, Henkel S, Kasten S, Holtappels M, Molari M. The Impact of Sea Ice Cover on Microbial Communities in Antarctic Shelf Sediments. Microorganisms 2023; 11:1572. [PMID: 37375074 DOI: 10.3390/microorganisms11061572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 05/30/2023] [Accepted: 06/03/2023] [Indexed: 06/29/2023] Open
Abstract
The area around the Antarctic Peninsula (AP) is facing rapid climatic and environmental changes, with so far unknown impacts on the benthic microbial communities of the continental shelves. In this study, we investigated the impact of contrasting sea ice cover on microbial community compositions in surface sediments from five stations along the eastern shelf of the AP using 16S ribosomal RNA (rRNA) gene sequencing. Redox conditions in sediments with long ice-free periods are characterized by a prevailing ferruginous zone, whereas a comparatively broad upper oxic zone is present at the heavily ice-covered station. Low ice cover stations were highly dominated by microbial communities of Desulfobacterota (mostly Sva1033, Desulfobacteria, and Desulfobulbia), Myxococcota, and Sva0485, whereas Gammaproteobacteria, Alphaproteobacteria, Bacteroidota, and NB1-j prevail at the heavy ice cover station. In the ferruginous zone, Sva1033 was the dominant member of Desulfuromonadales for all stations and, along with eleven other taxa, showed significant positive correlations with dissolved Fe concentrations, suggesting a significant role in iron reduction or an ecological relationship with iron reducers. Our results indicate that sea ice cover and its effect on organic carbon fluxes are the major drivers for changes in benthic microbial communities, favoring potential iron reducers at stations with increased organic matter fluxes.
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Affiliation(s)
- Marwa Baloza
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
- Faculty 2 Biology/Chemistry, University of Bremen, Leobener Str., 28359 Bremen, Germany
| | - Susann Henkel
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Sabine Kasten
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
- Faculty of Geosciences, University of Bremen, Klagenfurter Str., 28359 Bremen, Germany
- MARUM-Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany
| | - Moritz Holtappels
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
- MARUM-Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany
| | - Massimiliano Molari
- HGF-MPG Joint Research Group for Deep-Sea Ecology and Technology, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany
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11
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Liu X, Gu Y, Dong J, Li A, Zhuang G, Wang H. Iron-bearing minerals indicate sea-level rise of the East China Sea inner shelf since the last deglaciation. Sci Bull (Beijing) 2023:S2095-9273(23)00087-7. [PMID: 36774300 DOI: 10.1016/j.scib.2023.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Xiting Liu
- Key Laboratory of Submarine Geosciences and Prospecting Technology, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China; Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266061, China.
| | - Yu Gu
- Key Laboratory of Submarine Geosciences and Prospecting Technology, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
| | - Jiang Dong
- Key Laboratory of Marine Sedimentology and Environmental Geology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China
| | - Anchun Li
- Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
| | - Guangchao Zhuang
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China
| | - Houjie Wang
- Key Laboratory of Submarine Geosciences and Prospecting Technology, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China; Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266061, China
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12
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Neely SH, Raymond A. The influence of the taphonomically active zone on peat formation: Establishing modern peat analogs to decipher mangrove sub-habitats from historical peats. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.981537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
Mangroves create unique and highly productive wetland communities in intertidal zones of tropical and subtropical coastlines. Despite their many ecosystem services, such as carbon sequestration, mangroves remain threatened by climate change, sea-level rise, and human development. The inclusion of conservation paleobiology and long-term perspectives on how these ecosystems have responded to past environmental change can inform current policy and lead to more effective conservation and restoration management strategies for modern mangrove communities. In South Florida, humified plant debris, or peat, in mangroves provides this historical record. Our research takes a novel paleobiological approach by using plant organ- and taxon-based measures to describe the influence of the taphonomically active zone (TAZ: the zone near the surface of the substrate where taphonomic processes actively formation and degrade accumulated detritus) on the decomposition of mangrove peat with depth. This allows us to understand the taphonomic biases imposed on mangrove peat as it is sequestered into the sedimentological record and provides us with the paleoecological context to better interpret preserved peats and reconstruct past mangrove sub-habitats from peat cores. Accordingly, we collected modern surficial peat cores from two contrasting mangrove sub-habitats in Barnes Sound, FL. These surficial cores were characterized and compared to historical, deep cores from other South Florida mangrove peat deposits. By comparing the proportional abundance of mangrove peat constituents in these samples, we established modern analogs needed to interpret changes in the depositional environment of historical mangrove peats found in sediment cores, which is critical for understanding shoreline responses of mangroves to sea-level rise and anthropogenic change. We demonstrate that (1) leaf mat thickness may be a relative indicator of surficial peat decomposition rates because it correlates with the degree of tidal activity and detritivore access to the leaf litter layer; (2) root percentages are valid tools to differentiate between peats at depth, and can be used as relative indicators for the distance of in situ peat from shorelines; and (3) organismal signals, such as foraminifera and insect parts, provide a means for deciphering precursor mangrove sub-habitats from sequestered peats.
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13
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Louca S, Taylor GT, Astor YM, Buck KN, Muller-Karger FE. Transport-limited reactions in microbial systems. Environ Microbiol 2023; 25:268-282. [PMID: 36345893 DOI: 10.1111/1462-2920.16275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 10/29/2022] [Indexed: 11/11/2022]
Abstract
Predicting microbial metabolic rates and emergent biogeochemical fluxes remains challenging due to the many unknown population dynamical, physiological and reaction-kinetic parameters and uncertainties in species composition. Here, we show that the need for these parameters can be eliminated when population dynamics and reaction kinetics operate at much shorter time scales than physical mixing processes. Such scenarios are widespread in poorly mixed water columns and sediments. In this 'fast-reaction-transport' (FRT) limit, all that is required for predictions are chemical boundary conditions, the physical mixing processes and reaction stoichiometries, while no knowledge of species composition, physiology or population/reaction kinetic parameters is needed. Using time-series data spanning years 2001-2014 and depths 180-900 m across the permanently anoxic Cariaco Basin, we demonstrate that the FRT approach can accurately predict the dynamics of major electron donors and acceptors (Pearson r ≥ 0.9 in all cases). Hence, many microbial processes in this system are largely transport limited and thus predictable regardless of species composition, population dynamics and kinetics. Our approach enables predictions for many systems in which microbial community dynamics and kinetics are unknown. Our findings also reveal a mechanism for the frequently observed decoupling between function and taxonomy in microbial systems.
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Affiliation(s)
- Stilianos Louca
- Department of Biology, University of Oregon, Oregon, USA
- Institute of Ecology and Evolution, University of Oregon, Oregon, USA
| | - Gordon T Taylor
- School of Marine and Atmospheric Sciences, Stony Brook University, New York, New York, USA
| | - Yrene M Astor
- Estación de Investigaciones Marinas de Margarita, Fundación La Salle de Ciencias Naturales, Punta de Piedras, Estado Nueva Esparta, Venezuela
| | - Kristen N Buck
- College of Marine Science, University of South Florida, Florida, USA
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14
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Wu Z, Jiang X, Chen J, Wang S, Yao C. Geochemistry and release risk for nutrients in lake sediments based on diffusive gradients in thin films. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:40588-40607. [PMID: 36622617 DOI: 10.1007/s11356-022-24961-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 12/20/2022] [Indexed: 01/10/2023]
Abstract
A comprehensive understanding of the mobility of both nitrogen (N) and phosphorus (P) and the inter-relationships between P, N, and iron (Fe) in sediments is important for controlling the "internal loadings" of nutrients in lakes. In this research, diffusive gradients in thin film (DGT) assemblies with binding layers (ZrO-AT, chelex, and ZrO) were designed for PO4-P, Fe, ammonium (NH4-N), and nitrate (NO3-N) at sediment/water interface (SWI) in Western Lake Taihu (China). The biogeochemical processes of N and P related to the physicochemical properties, the dynamic P transfer, the distribution characteristics of P microniches, and the estimation of the release risks in sediments in Western Lake Taihu were simultaneously revealed by the passive sampling technique-DGT with the high spatial resolutions (millimeter and sub-millimeter). Based on DGT concentration (CDGT) related to physicochemical properties in sediments, (1) P biogeochemical reactions included P release from Fe-bound P during Fe reduction, algae biomass decomposition, and phosphatase enzyme activity increased by NH4-N; (2) denitrification and dissimilatory nitrate reduction to ammonium (DNRA) led to exchangeable ammonium (NH4ex) enrichment and NH4-N release; anammox depleted NH4-N transfer; organic matter (OM) mineralization favored NH4-N release; and (3) aerobic nitrification led to NO3-N remobilization; denitrification and DNRA reduced NO3-N release. Redox status, OM, Fe, aluminum, or calcium influenced mobilization of nutrients. The numerical model of DGT-induced fluxes in sediments was used for dynamic P transfers with resupply types ("slow" ~ "fast") controlled by labile P pool, resupply constant, response time, and Dspt rate. The formation of P microniches in two dimensions was revealed. Sediment P release risk index (0.49 ~ 36.85 [lg (nmol cm-3 d-1)]) with "light" ~ "high" risks and diffusive fluxes across SWI (µg m-2 d-1) of 15.0 ~ 639 (PO4-P), - 1403 ~ 5010 (NH4-N), and - 1395 ~ 149 (NO3-N) were derived and lake management strategies were provided. The DGT technique provides the characterization of the mobilization of nutrients and evidence for biogeochemical processes at the fine spatial scales for control of internal loadings in sediments.
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Affiliation(s)
- Zhihao Wu
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Institute of Lake Environment, Chinese Research Academy of Environmental Sciences (CRAES), Beijing, 100012, China.,State Environmental Protection Key Laboratory for Lake Pollution Control, Institute of Lake Environment, Chinese Research Academy of Environmental Sciences (CRAES), Beijing, 100012, China
| | - Xia Jiang
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Institute of Lake Environment, Chinese Research Academy of Environmental Sciences (CRAES), Beijing, 100012, China.,State Environmental Protection Key Laboratory for Lake Pollution Control, Institute of Lake Environment, Chinese Research Academy of Environmental Sciences (CRAES), Beijing, 100012, China
| | - Junyi Chen
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Institute of Lake Environment, Chinese Research Academy of Environmental Sciences (CRAES), Beijing, 100012, China.,State Environmental Protection Key Laboratory for Lake Pollution Control, Institute of Lake Environment, Chinese Research Academy of Environmental Sciences (CRAES), Beijing, 100012, China
| | - Shuhang Wang
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Institute of Lake Environment, Chinese Research Academy of Environmental Sciences (CRAES), Beijing, 100012, China. .,State Environmental Protection Key Laboratory for Lake Pollution Control, Institute of Lake Environment, Chinese Research Academy of Environmental Sciences (CRAES), Beijing, 100012, China.
| | - Cheng Yao
- State Environmental Protection Key Laboratory for Lake Pollution Control, Institute of Lake Environment, Chinese Research Academy of Environmental Sciences (CRAES), Beijing, 100012, China.,College of Water Science, Beijing Normal University, Beijing, 100875, China
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15
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Eukaryogenesis and oxygen in Earth history. Nat Ecol Evol 2022; 6:520-532. [PMID: 35449457 DOI: 10.1038/s41559-022-01733-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 03/15/2022] [Indexed: 02/07/2023]
Abstract
The endosymbiotic origin of mitochondria during eukaryogenesis has long been viewed as an adaptive response to the oxygenation of Earth's surface environment, presuming a fundamentally aerobic lifestyle for the free-living bacterial ancestors of mitochondria. This oxygen-centric view has been robustly challenged by recent advances in the Earth and life sciences. While the permanent oxygenation of the atmosphere above trace concentrations is now thought to have occurred 2.2 billion years ago, large parts of the deep ocean remained anoxic until less than 0.5 billion years ago. Neither fossils nor molecular clocks correlate the origin of mitochondria, or eukaryogenesis more broadly, to either of these planetary redox transitions. Instead, mitochondria-bearing eukaryotes are consistently dated to between these two oxygenation events, during an interval of pervasive deep-sea anoxia and variable surface-water oxygenation. The discovery and cultivation of the Asgard archaea has reinforced metabolic evidence that eukaryogenesis was initially mediated by syntrophic H2 exchange between an archaeal host and an α-proteobacterial symbiont living under anoxia. Together, these results temporally, spatially and metabolically decouple the earliest stages of eukaryogenesis from the oxygen content of the surface ocean and atmosphere. Rather than reflecting the ancestral metabolic state, obligate aerobiosis in eukaryotes is most probably derived, having only become globally widespread over the past 1 billion years as atmospheric oxygen approached modern levels.
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16
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17
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Gadol HJ, Elsherbini J, Kocar BD. Methanogen Productivity and Microbial Community Composition Varies With Iron Oxide Mineralogy. Front Microbiol 2022; 12:705501. [PMID: 35250895 PMCID: PMC8894893 DOI: 10.3389/fmicb.2021.705501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 12/27/2021] [Indexed: 01/04/2023] Open
Abstract
Quantifying the flux of methane from terrestrial environments remains challenging, owing to considerable spatial and temporal variability in emissions. Amongst a myriad of factors, variation in the composition of electron acceptors, including metal (oxyhydr)oxides, may impart controls on methane emission. The purpose of this research is to understand how iron (oxyhydr)oxide minerals with varied physicochemical properties influence microbial methane production and subsequent microbial community development. Incubation experiments, using lake sediment as an inoculum and acetate as a carbon source, were used to understand the influence of one poorly crystalline iron oxide mineral, ferrihydrite, and two well-crystalline minerals, hematite and goethite, on methane production. Iron speciation, headspace methane, and 16S-rRNA sequencing microbial community data were measured over time. Substantial iron reduction only occurred in the presence of ferrihydrite while hematite and goethite had little effect on methane production throughout the incubations. In ferrihydrite experiments the time taken to reach the maximum methane production rate was slower than under other conditions, but methane production, eventually occurred in the presence of ferrihydrite. We suggest that this is due to ferrihydrite transformation into more stable minerals like magnetite and goethite or surface passivation by Fe(II). While all experimental conditions enriched for Methanosarcina, only the presence of ferrihydrite enriched for iron reducing bacteria Geobacter. Additionally, the presence of ferrihydrite continued to influence microbial community development after the onset of methanogenesis, with the dissimilarity between communities growing in ferrihydrite compared to no-Fe-added controls increasing over time. This work improves our understanding of how the presence of different iron oxides influences microbial community composition and methane production in soils and sediments.
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Affiliation(s)
- Hayley J. Gadol
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
- *Correspondence: Hayley J. Gadol,
| | - Joseph Elsherbini
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
- Graduate Program in Microbiology, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Benjamin D. Kocar
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
- Environmental Laboratory, U.S. Army Engineer Research and Development Center, Vicksburg, MS, United States
- Benjamin D. Kocar,
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18
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Frederiksen JA, Klaebe RM, Farkaš J, Swart PK, Frei R. Cadmium isotopes in Bahamas platform carbonates: A base for reconstruction of past surface water bioproductivity and their link with chromium isotopes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150565. [PMID: 34582867 DOI: 10.1016/j.scitotenv.2021.150565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/20/2021] [Accepted: 09/20/2021] [Indexed: 06/13/2023]
Abstract
The distribution of cadmium (Cd) within the oceans strongly suggests that it is used as a nutrient by marine phytoplankton. Biologically induced removal of Cd from modern surface waters is accompanied by an isotopic fractionation leaving surface-waters enriched in isotopically heavy Cd. This first study focusses on tying the Cd isotopic record preserved in modern shallow platform carbonates of the Great Bahama Bank (GBB) to conditions in the upper water column, and provides a base for future studies aiming at reconstructing past bioproductivity levels in ancient ocean/basin surface waters. In addition, we compare δ114Cd values with previously published chromium (Cr) isotope values and link signals of bioproductivity with redox conditions in the surface waters. The GBB core samples yield [Cd] (21-188 μg/kg), which increases with depth alongside changes in carbonate mineralogy related to sediment supply and diagenesis. The δ114Cd values of these carbonates are mainly positively fractionated with an average of 0.11‰ ± 0.17 (2σ; n = 17) relative to the NIST 3108 reference standard. Unlike previously observed for Cr isotopes, there is no control of δ114Cd values by relative abundances of the carbonate polymorphs aragonite and calcite in the studied profile. Likewise, δ114Cd values are not correlated to major and trace element (e.g. Ca, Mg, Mn and Sr) contents. We postulate that the burial and diagenetic processes of carbonate cannot modify the Cd isotope signals. Using the experimental fractionation factor for Cd into calcite (-0.45‰), calculated seawater δ114Cd of +0.56 ± 0.17‰ is in agreement with values for modern North Atlantic Surface Seawater. This study's results suggest that δ114Cd values in carbonates are a reliable tool for reconstruction of bioproductivity levels in past surface seawaters, and open new possibilities in combination with Cr isotopes to link these with past ocean redox.
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Affiliation(s)
| | | | - Juraj Farkaš
- Department of Earth Sciences, The University of Adelaide, SA 5005, Australia.
| | | | - Robert Frei
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark.
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Microbial community structure in hadal sediments: high similarity along trench axes and strong changes along redox gradients. THE ISME JOURNAL 2021; 15:3455-3467. [PMID: 34103697 PMCID: PMC8629969 DOI: 10.1038/s41396-021-01021-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 05/11/2021] [Accepted: 05/20/2021] [Indexed: 02/05/2023]
Abstract
Hadal trench sediments are hotspots of biogeochemical activity in the deep sea, but the biogeochemical and ecological factors that shape benthic hadal microbial communities remain unknown. Here, we sampled ten hadal sites from two trench regions with a vertical resolution of down to 1 cm. We sequenced 16S rRNA gene amplicons using universal and archaea-specific primer sets and compared the results to biogeochemical parameters. Despite bathymetric and depositional heterogeneity we found a high similarity of microbial communities within each of the two trench axes, while composition at the phylum level varied strongly with sediment depth in conjunction with the redox stratification into oxic, nitrogenous, and ferruginous zones. As a result, communities of a given sediment horizon were more similar to each other across a distance of hundreds of kilometers within each trench, than to those of adjacent horizons from the same sites separated only by centimeters. Total organic carbon content statistically only explained a small part of the variation within and between trenches, and did not explain the community differences observed between the hadal and adjacent shallower sites. Anaerobic taxa increased in abundance at the top of the ferruginous zone, seeded by organisms deposited at the sediment surface and surviving burial through the upper redox zones. While an influence of other potential factors such as geographic isolation, hydrostatic pressure, and non-steady state depositional regimes could not be discerned, redox stratification and diagenesis appear to be the main selective forces that structure community composition in hadal sediments.
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20
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Anammox bacteria drive fixed nitrogen loss in hadal trench sediments. Proc Natl Acad Sci U S A 2021; 118:2104529118. [PMID: 34764222 DOI: 10.1073/pnas.2104529118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2021] [Indexed: 01/04/2023] Open
Abstract
Benthic N2 production by microbial denitrification and anammox is the largest sink for fixed nitrogen in the oceans. Most N2 production occurs on the continental shelves, where a high flux of reactive organic matter fuels the depletion of nitrate close to the sediment surface. By contrast, N2 production rates in abyssal sediments are low due to low inputs of reactive organics, and nitrogen transformations are dominated by aerobic nitrification and the release of nitrate to the bottom water. Here, we demonstrate that this trend is reversed in the deepest parts of the oceans, the hadal trenches, where focusing of reactive organic matter enhances benthic microbial activity. Thus, at ∼8-km depth in the Atacama Trench, underlying productive surface waters, nitrate is depleted within a few centimeters of the sediment surface, N2 production rates reach those reported from some continental margin sites, and fixed nitrogen loss is mainly conveyed by anammox bacteria. These bacteria are closely related to those known from shallow oxygen minimum zone waters, and comparison of activities measured in the laboratory and in situ suggest they are piezotolerant. Even the Kermadec Trench, underlying oligotrophic surface waters, exhibits substantial fixed N removal. Our results underline the role of hadal sediments as hot spots of deep-sea biological activity, revealing a fully functional benthic nitrogen cycle at high hydrostatic pressure and pointing to hadal sediments as a previously unexplored niche for anaerobic microbial ecology and diagenesis.
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21
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Li WJ, Ma WW, Ren JH, Qin SS, Sun WX, Zhu MX. Assessing the impacts of differential depositional settings and/or anthropogenic perturbations on sulfur and iron diagenesis in sediments of the Bohai Sea and North Yellow Sea. MARINE POLLUTION BULLETIN 2021; 172:112894. [PMID: 34464821 DOI: 10.1016/j.marpolbul.2021.112894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 06/13/2023]
Abstract
Natural processes and human activities exert important impacts on elemental cycling in coastal sediments, which has not been well documented. Sediments in the Bohai Sea and North Yellow Sea were investigated to assess the impacts of the Yellow River inputs and/or anthropogenic perturbations on diagenesis of iron and sulfur. Labile iron (0.5 M HCl-extractable iron) in the sediments is low due to iron-poor nature of source materials. Dynamic regimes and low availability of labile organic carbon (OC) result in relatively low sulfide contents in deltaic sediments. However, low but continuous supply of labile OC exported from an anthropogenically impacted bay could substantially elevate sulfide burial in sediments near the bay. Neither offshore oil exploitations nor frequent algal blooms in the seas have detectable influences on iron and sulfur diagenesis in the sediments. The sediments are capable of quickly consuming porewater sulfide by reaction with reactive iron under the current conditions.
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Affiliation(s)
- Wen-Jun Li
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China; National Marine Environmental Monitoring Center, Ministry of Ecology and Environment, Dalian 116023, China
| | - Wei-Wei Ma
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China
| | - Jian-Hua Ren
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China
| | - Shuang-Shuang Qin
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China
| | - Wen-Xuan Sun
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China
| | - Mao-Xu Zhu
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
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22
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Zhang J, Li C, Zhang Y. Geological evidences and mechanisms for oceanic anoxic events during the Early Paleozoic. CHINESE SCIENCE BULLETIN-CHINESE 2021. [DOI: 10.1360/tb-2021-0535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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23
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Kong Y, Lei H, Zhang Z, Cheng W, Wang B, Pan F, Huang F, Huang F, Li W. Depth profiles of geochemical features, geochemical activities and biodiversity of microbial communities in marine sediments from the Shenhu area, the northern South China Sea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 779:146233. [PMID: 34030248 DOI: 10.1016/j.scitotenv.2021.146233] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 06/12/2023]
Abstract
The biogeochemical processes, anaerobic oxidation of methane (AOM) and methanogenesis, control methane emission and create distinct geochemical profiles with depth in marine sediments. Correlating the capacities and biodiversity of the microbial communities in marine sediments remains challenging. We therefore investigated the geochemical constituents and the capabilities and diversity of microbial communities in sediments at different depths in two cores from the Shenhu area in the northern South China Sea, which is characterized by underlying gas hydrates. The geochemical features, sulfate concentration decreased linearly and the acid volatile sulfur accumulated from 4 m below the seafloor (mbsf) to the bottom, indicating significant sulfate reduction. However, the methane concentration was relatively low and showed irregular trends, indicating that our study cores did not reach the sulfate-methane transition zone (SMTZ). Nevertheless, incubation experiments showed that the microbial groups in sediments performed AOM and methanogenesis in the region where sulfate decreased linearly above the SMTZ. We mapped the diversity and abundance of microbial communities in sediments with depth using high-throughput sequencing. A small proportion of known methanogens (<0.3%) may have been responsible for the methanogenesis during incubation. No classical archaeal anaerobic methanotroph (ANME) sequences were detected across all samples; only a small amount of SEEP-SRB1 were detected, and their abundance did not increase with increasing depth. Thus, unknown or unconventional phylotypes may have participated in AOM during the incubation, and the dominant phylum Bathyarchaeota or the small number of detected methanogens are the most likely performers of AOM.
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Affiliation(s)
- Yuan Kong
- Department of Geological Oceanography, College of Ocean & Earth Science, Xiamen University, Xiamen 361102, PR China
| | - Huaiyan Lei
- Department of Geological Oceanography, College of Ocean & Earth Science, Xiamen University, Xiamen 361102, PR China.
| | - Zilian Zhang
- Department of Geological Oceanography, College of Ocean & Earth Science, Xiamen University, Xiamen 361102, PR China
| | - Weidong Cheng
- Department of Geological Oceanography, College of Ocean & Earth Science, Xiamen University, Xiamen 361102, PR China
| | - Bin Wang
- Department of Geological Oceanography, College of Ocean & Earth Science, Xiamen University, Xiamen 361102, PR China
| | - Fulong Pan
- Department of Geological Oceanography, College of Ocean & Earth Science, Xiamen University, Xiamen 361102, PR China
| | - Fanfan Huang
- Department of Geological Oceanography, College of Ocean & Earth Science, Xiamen University, Xiamen 361102, PR China
| | - Fanli Huang
- Department of Geological Oceanography, College of Ocean & Earth Science, Xiamen University, Xiamen 361102, PR China
| | - Wenqing Li
- Key Laboratory of Mineral Resources Evaluation in Northeast China, Ministry of Land and Resources, Changchun 130061, PR China
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Paredes GF, Viehboeck T, Lee R, Palatinszky M, Mausz MA, Reipert S, Schintlmeister A, Maier A, Volland JM, Hirschfeld C, Wagner M, Berry D, Markert S, Bulgheresi S, König L. Anaerobic Sulfur Oxidation Underlies Adaptation of a Chemosynthetic Symbiont to Oxic-Anoxic Interfaces. mSystems 2021; 6:e0118620. [PMID: 34058098 PMCID: PMC8269255 DOI: 10.1128/msystems.01186-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 04/20/2021] [Indexed: 11/23/2022] Open
Abstract
Chemosynthetic symbioses occur worldwide in marine habitats, but comprehensive physiological studies of chemoautotrophic bacteria thriving on animals are scarce. Stilbonematinae are coated by thiotrophic Gammaproteobacteria. As these nematodes migrate through the redox zone, their ectosymbionts experience varying oxygen concentrations. However, nothing is known about how these variations affect their physiology. Here, by applying omics, Raman microspectroscopy, and stable isotope labeling, we investigated the effect of oxygen on "Candidatus Thiosymbion oneisti." Unexpectedly, sulfur oxidation genes were upregulated in anoxic relative to oxic conditions, but carbon fixation genes and incorporation of 13C-labeled bicarbonate were not. Instead, several genes involved in carbon fixation were upregulated under oxic conditions, together with genes involved in organic carbon assimilation, polyhydroxyalkanoate (PHA) biosynthesis, nitrogen fixation, and urea utilization. Furthermore, in the presence of oxygen, stress-related genes were upregulated together with vitamin biosynthesis genes likely necessary to withstand oxidative stress, and the symbiont appeared to proliferate less. Based on its physiological response to oxygen, we propose that "Ca. T. oneisti" may exploit anaerobic sulfur oxidation coupled to denitrification to proliferate in anoxic sand. However, the ectosymbiont would still profit from the oxygen available in superficial sand, as the energy-efficient aerobic respiration would facilitate carbon and nitrogen assimilation. IMPORTANCE Chemoautotrophic endosymbionts are famous for exploiting sulfur oxidization to feed marine organisms with fixed carbon. However, the physiology of thiotrophic bacteria thriving on the surface of animals (ectosymbionts) is less understood. One longstanding hypothesis posits that attachment to animals that migrate between reduced and oxic environments would boost sulfur oxidation, as the ectosymbionts would alternatively access sulfide and oxygen, the most favorable electron acceptor. Here, we investigated the effect of oxygen on the physiology of "Candidatus Thiosymbion oneisti," a gammaproteobacterium which lives attached to marine nematodes inhabiting shallow-water sand. Surprisingly, sulfur oxidation genes were upregulated under anoxic relative to oxic conditions. Furthermore, under anoxia, the ectosymbiont appeared to be less stressed and to proliferate more. We propose that animal-mediated access to oxygen, rather than enhancing sulfur oxidation, would facilitate assimilation of carbon and nitrogen by the ectosymbiont.
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Affiliation(s)
- Gabriela F. Paredes
- University of Vienna, Department of Functional and Evolutionary Ecology, Environmental Cell Biology Group, Vienna, Austria
| | - Tobias Viehboeck
- University of Vienna, Department of Functional and Evolutionary Ecology, Environmental Cell Biology Group, Vienna, Austria
- University of Vienna, Center for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
| | - Raymond Lee
- Washington State University, School of Biological Sciences, Pullman, Washington, USA
| | - Marton Palatinszky
- University of Vienna, Center for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
| | - Michaela A. Mausz
- University of Warwick, School of Life Sciences, Coventry, United Kingdom
| | - Siegfried Reipert
- University of Vienna, Core Facility Cell Imaging and Ultrastructure Research, Vienna, Austria
| | - Arno Schintlmeister
- University of Vienna, Center for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
- University of Vienna, Center for Microbiology and Environmental Systems Science, Large-Instrument Facility for Environmental and Isotope Mass Spectrometry, Vienna, Austria
| | - Andreas Maier
- University of Vienna, Faculty of Geosciences, Geography, and Astronomy, Department of Geography and Regional Research, Geoecology, Vienna, Austria
| | - Jean-Marie Volland
- University of Vienna, Department of Functional and Evolutionary Ecology, Environmental Cell Biology Group, Vienna, Austria
| | - Claudia Hirschfeld
- University of Greifswald, Institute of Pharmacy, Department of Pharmaceutical Biotechnology, Greifswald, Germany
| | - Michael Wagner
- University of Vienna, Center for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
- Aalborg University, Department of Chemistry and Bioscience, Aalborg, Denmark
| | - David Berry
- University of Vienna, Center for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
- Joint Microbiome Facility of the Medical University of Vienna and the University of Vienna, Vienna, Austria
| | - Stephanie Markert
- University of Greifswald, Institute of Pharmacy, Department of Pharmaceutical Biotechnology, Greifswald, Germany
| | - Silvia Bulgheresi
- University of Vienna, Department of Functional and Evolutionary Ecology, Environmental Cell Biology Group, Vienna, Austria
| | - Lena König
- University of Vienna, Department of Functional and Evolutionary Ecology, Environmental Cell Biology Group, Vienna, Austria
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25
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Active methanogenesis during the melting of Marinoan snowball Earth. Nat Commun 2021; 12:955. [PMID: 33574253 PMCID: PMC7878791 DOI: 10.1038/s41467-021-21114-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 01/08/2021] [Indexed: 11/16/2022] Open
Abstract
Geological evidence indicates that the deglaciation of Marinoan snowball Earth ice age (~635 Myr ago) was associated with intense continental weathering, recovery of primary productivity, transient marine euxinia, and potentially extensive CH4 emission. It is proposed that the deglacial CH4 emissions may have provided positive feedbacks for ice melting and global warming. However, the origin of CH4 remains unclear. Here we report Ni isotopes (δ60Ni) and Yttrium-rare earth element (YREE) compositions of syndepositional pyrites from the upper most Nantuo Formation (equivalent deposits of the Marinoan glaciation), South China. The Nantuo pyrite displays anti-correlations between Ni concentration and δ60Ni, and between Ni concentration and Sm/Yb ratio, suggesting mixing between Ni in seawater and Ni from methanogens. Our study indicates active methanogenesis during the termination of Marinoan snowball Earth. This suggests that methanogenesis was fueled by methyl sulfides produced in sulfidic seawater during the deglacial recovery of marine primary productivity. The deglaciation of Marinoan snowball Earth (~635 Myr ago) has been associated with potentially extensive CH4 emissions in relation to transient marine euxinia. Here, the authors find that active methanogenesis occurred during the termination of Marinoan snowball Earth, fueled by methyl sulfide production in sulfidic seawater.
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Ruiz-González C, Rodellas V, Garcia-Orellana J. The microbial dimension of submarine groundwater discharge: current challenges and future directions. FEMS Microbiol Rev 2021; 45:6128669. [PMID: 33538813 PMCID: PMC8498565 DOI: 10.1093/femsre/fuab010] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 01/28/2021] [Indexed: 12/22/2022] Open
Abstract
Despite the relevance of submarine groundwater discharge (SGD) for ocean biogeochemistry, the microbial dimension of SGD remains poorly understood. SGD can influence marine microbial communities through supplying chemical compounds and microorganisms, and in turn, microbes at the land–ocean transition zone determine the chemistry of the groundwater reaching the ocean. However, compared with inland groundwater, little is known about microbial communities in coastal aquifers. Here, we review the state of the art of the microbial dimension of SGD, with emphasis on prokaryotes, and identify current challenges and future directions. Main challenges include improving the diversity description of groundwater microbiota, characterized by ultrasmall, inactive and novel taxa, and by high ratios of sediment-attached versus free-living cells. Studies should explore microbial dynamics and their role in chemical cycles in coastal aquifers, the bidirectional dispersal of groundwater and seawater microorganisms, and marine bacterioplankton responses to SGD. This will require not only combining sequencing methods, visualization and linking taxonomy to activity but also considering the entire groundwater–marine continuum. Interactions between traditionally independent disciplines (e.g. hydrogeology, microbial ecology) are needed to frame the study of terrestrial and aquatic microorganisms beyond the limits of their presumed habitats, and to foster our understanding of SGD processes and their influence in coastal biogeochemical cycles.
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Affiliation(s)
- Clara Ruiz-González
- Institut de Ciències del Mar (ICM-CSIC). Passeig Marítim de la Barceloneta 37-49, E08003 Barcelona, Spain
| | - Valentí Rodellas
- Institut de Ciència i Tecnologia Ambientals (ICTA-UAB), Universitat Autònoma de Barcelona, E08193 Bellaterra, Spain
| | - Jordi Garcia-Orellana
- Institut de Ciència i Tecnologia Ambientals (ICTA-UAB), Universitat Autònoma de Barcelona, E08193 Bellaterra, Spain.,Departament de Física, Universitat Autònoma de Barcelona, E08193 Bellaterra, Spain
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27
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Barkow IS, Oswald SE, Lensing HJ, Munz M. Seasonal dynamics modifies fate of oxygen, nitrate, and organic micropollutants during bank filtration - temperature-dependent reactive transport modeling of field data. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:9682-9700. [PMID: 33151490 PMCID: PMC7884598 DOI: 10.1007/s11356-020-11002-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 09/25/2020] [Indexed: 05/25/2023]
Abstract
Bank filtration is considered to improve water quality through microbially mediated degradation of pollutants and is suitable for waterworks to increase their production. In particular, aquifer temperatures and oxygen supply have a great impact on many microbial processes. To investigate the temporal and spatial behavior of selected organic micropollutants during bank filtration in dependence of relevant biogeochemical conditions, we have set up a 2D reactive transport model using MODFLOW and PHT3D under the user interface ORTI3D. The considered 160-m-long transect ranges from the surface water to a groundwater extraction well of the adjacent waterworks. For this purpose, water levels, temperatures, and chemical parameters were regularly measured in the surface water and groundwater observation wells over one and a half years. To simulate the effect of seasonal temperature variations on microbial mediated degradation, we applied an empirical temperature factor, which yields a strong reduction of the degradation rate at groundwater temperatures below 11 °C. Except for acesulfame, the considered organic micropollutants are substantially degraded along their subsurface flow paths with maximum degradation rates in the range of 10-6 mol L-1 s-1. Preferential biodegradation of phenazone, diclofenac, and valsartan was found under oxic conditions, whereas carbamazepine and sulfamethoxazole were degraded under anoxic conditions. This study highlights the influence of seasonal variations in oxygen supply and temperature on the fate of organic micropollutants in surface water infiltrating into an aquifer.
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Affiliation(s)
- Isolde S Barkow
- Institute of Environmental Science and Geography, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany.
| | - Sascha E Oswald
- Institute of Environmental Science and Geography, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany
| | - Hermann-Josef Lensing
- Department of Geotechnical Engineering, Federal Waterways Engineering and Research Institute (BAW), Kussmaulstraße 17, 76187, Karlsruhe, Germany
| | - Matthias Munz
- Institute of Environmental Science and Geography, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany
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28
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Li C, Shi W, Cheng M, Jin C, Algeo TJ. The redox structure of Ediacaran and early Cambrian oceans and its controls. Sci Bull (Beijing) 2020; 65:2141-2149. [PMID: 36732967 DOI: 10.1016/j.scib.2020.09.023] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 08/24/2020] [Accepted: 08/25/2020] [Indexed: 02/04/2023]
Abstract
The rapid diversification of early animals during the Ediacaran (635-541 Ma) and early Cambrian (ca. 541-509 Ma) has frequently been attributed to increasing oceanic oxygenation. However, the pattern of oceanic oxygenation and its relationship to early animal evolution remain in debate. In this review, we examine the redox structure of Ediacaran and early Cambrian oceans and its controls, offering new insights into contemporaneous oceanic oxygenation patterns and their role in the coevolution of environments and early animals. We review the development of marine redox models which, in combination with independent distal deep-ocean redox proxies, supports a highly redox-stratified shelf and an anoxia-dominated deep ocean during the Ediacaran and early Cambrian. Geochemical and modeling evidence indicates that the marine redox structure was likely controlled by low atmospheric O2 levels and low seawater vertical mixing rates on shelves at that time. Furthermore, theoretical analysis and increasing geochemical evidence, particularly from South China, show that limited sulfate availability was a primary control on the attenuation of mid-depth euxinia offshore, in contrast to the existing paradigm invoking decreased organic carbon fluxes distally. In light of our review, we infer that if oceanic oxygenation indeed triggered the rise of early animals, it must have done so through a shelf oxygenation which was probably driven by elevated oxidant availability. Our review calls for further studies on Ediacaran-Cambrian marine redox structure and its controls, particularly from regions outside of South China, in order to better understand the coevolutionary relationship between oceanic redox and early animals.
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Affiliation(s)
- Chao Li
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
| | - Wei Shi
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Meng Cheng
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Chengsheng Jin
- Yunnan Key Laboratory for Palaeobiology, Yunnan University, Kunming 650091, China
| | - Thomas J Algeo
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; State Key Laboratory of Geological Process and Mineral Resources, China University of Geosciences, Wuhan 430074, China; Department of Geology, University of Cincinnati, Cincinnati OH45221, USA
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29
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Louca S, Rubin IN, Madilao LL, Bohlmann J, Doebeli M, Wegener Parfrey L. Effects of forced taxonomic transitions on metabolic composition and function in microbial microcosms. ENVIRONMENTAL MICROBIOLOGY REPORTS 2020; 12:514-524. [PMID: 32618124 DOI: 10.1111/1758-2229.12866] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 06/29/2020] [Indexed: 06/11/2023]
Abstract
Surveys of microbial systems indicate that in many situations taxonomy and function may constitute largely independent ('decoupled') axes of variation. However, this decoupling is rarely explicitly tested experimentally, partly because it is hard to directly induce taxonomic variation without affecting functional composition. Here we experimentally evaluate this paradigm using microcosms resembling lake sediments and subjected to two different levels of salinity (0 and 19) and otherwise similar environmental conditions. We used DNA sequencing for taxonomic and functional profiling of bacteria and archaea and physicochemical measurements to monitor metabolic function, over 13 months. We found that the taxonomic composition of the saline systems gradually but strongly diverged from the fresh systems. In contrast, the metabolic composition (in terms of proportions of various genes) remained nearly identical across treatments and over time. Oxygen consumption rates and methane concentrations were substantially lower in the saline treatment, however, their similarity either increased (for oxygen) or did not change significantly (for methane) between the first and last sampling time, indicating that the lower metabolic activity in the saline treatments was directly and immediately caused by salinity rather than the gradual taxonomic divergence. Our experiment demonstrates that strong taxonomic shifts need not directly affect metabolic rates.
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Affiliation(s)
- Stilianos Louca
- Department of Biology, University of Oregon, Eugene, OR, USA
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, USA
| | - Ilan N Rubin
- Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Lufiani L Madilao
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
- Wine Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Jörg Bohlmann
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
- Wine Research Centre, University of British Columbia, Vancouver, BC, Canada
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada
- Department of Botany, University of British Columbia, Vancouver, BC, Canada
| | - Michael Doebeli
- Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
- Department of Mathematics, University of British Columbia, Vancouver, BC, Canada
| | - Laura Wegener Parfrey
- Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
- Department of Botany, University of British Columbia, Vancouver, BC, Canada
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30
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Costa L, Mirlean N. Selenium Enrichment in Pore Water of Estuarine Sediments Subject to Salt Marsh Vegetation Bioirrigation (Patos Estuary, Southern Brazil). BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2020; 105:468-473. [PMID: 32886144 DOI: 10.1007/s00128-020-02978-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 08/19/2020] [Indexed: 06/11/2023]
Abstract
Selenium (Se), iron (Fe), and free sulfides contents in pore waters were measured to study the liberation of soluble Se in suboxic conditions. The sediment core was collected in a salt marsh in Patos Lagoon estuary (southern Brazil), and it was obtained during a brackish water period, in a low intertidal stand vegetated by Spartina alterniflora. The redox potential (Eh), pH, andacid volatile sulfides (AVS) content were also investigated. Pore water results sustained the idea that S. alterniflora roots promote oxygen penetration to depths of ca. 10 cm below the salt marsh surface, increasing Eh and lowering the pH in this interval. High Se concentrations (e.g., 16.9 µg L-1), that are above US. EPA environmental criteria, were observed in the pore water to depths between 10 and 20 cm and are associated to low AVS contents and high concentrations of free sulfides. In the first 10 cm the lowering of Se contents probably happens due the low pH and biological volatilization of the metalloid.
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Affiliation(s)
- Larissa Costa
- Oceanography Institute, Federal University of Rio Grande, Av. Itália km 08 Campus Carreiros, Rio Grande, RS, 96201-900, Brazil.
| | - Nicolai Mirlean
- Oceanography Institute, Federal University of Rio Grande, Av. Itália km 08 Campus Carreiros, Rio Grande, RS, 96201-900, Brazil
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31
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Zou D, Liu H, Li M. Community, Distribution, and Ecological Roles of Estuarine Archaea. Front Microbiol 2020; 11:2060. [PMID: 32983044 PMCID: PMC7484942 DOI: 10.3389/fmicb.2020.02060] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 08/05/2020] [Indexed: 12/04/2022] Open
Abstract
Archaea are diverse and ubiquitous prokaryotes present in both extreme and moderate environments. Estuaries, serving as links between the land and ocean, harbor numerous microbes that are relatively highly active because of massive terrigenous input of nutrients. Archaea account for a considerable portion of the estuarine microbial community. They are diverse and play key roles in the estuarine biogeochemical cycles. Ammonia-oxidizing archaea (AOA) are an abundant aquatic archaeal group in estuaries, greatly contributing estuarine ammonia oxidation. Bathyarchaeota are abundant in sediments, and they may involve in sedimentary organic matter degradation, acetogenesis, and, potentially, methane metabolism, based on genomics. Other archaeal groups are also commonly detected in estuaries worldwide. They include Euryarchaeota, and members of the DPANN and Asgard archaea. Based on biodiversity surveys of the 16S rRNA gene and some functional genes, the distribution and abundance of estuarine archaea are driven by physicochemical factors, such as salinity and oxygen concentration. Currently, increasing amount of genomic information for estuarine archaea is becoming available because of the advances in sequencing technologies, especially for AOA and Bathyarchaeota, leading to a better understanding of their functions and environmental adaptations. Here, we summarized the current knowledge on the community composition and major archaeal groups in estuaries, focusing on AOA and Bathyarchaeota. We also highlighted the unique genomic features and potential adaptation strategies of estuarine archaea, pointing out major unknowns in the field and scope for future research.
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Affiliation(s)
- Dayu Zou
- SZU-HKUST Joint Ph.D. Program in Marine Environmental Science, Shenzhen University, Shenzhen, China
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, China
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Hongbin Liu
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
- Hong Kong Branch of Southern Marine Science & Engineering Guangdong Laboratory, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Meng Li
- SZU-HKUST Joint Ph.D. Program in Marine Environmental Science, Shenzhen University, Shenzhen, China
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, China
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32
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Cole DB, Mills DB, Erwin DH, Sperling EA, Porter SM, Reinhard CT, Planavsky NJ. On the co-evolution of surface oxygen levels and animals. GEOBIOLOGY 2020; 18:260-281. [PMID: 32175670 DOI: 10.1111/gbi.12382] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 01/04/2020] [Accepted: 01/22/2020] [Indexed: 05/22/2023]
Abstract
Few topics in geobiology have been as extensively debated as the role of Earth's oxygenation in controlling when and why animals emerged and diversified. All currently described animals require oxygen for at least a portion of their life cycle. Therefore, the transition to an oxygenated planet was a prerequisite for the emergence of animals. Yet, our understanding of Earth's oxygenation and the environmental requirements of animal habitability and ecological success is currently limited; estimates for the timing of the appearance of environments sufficiently oxygenated to support ecologically stable populations of animals span a wide range, from billions of years to only a few million years before animals appear in the fossil record. In this light, the extent to which oxygen played an important role in controlling when animals appeared remains a topic of debate. When animals originated and when they diversified are separate questions, meaning either one or both of these phenomena could have been decoupled from oxygenation. Here, we present views from across this interpretive spectrum-in a point-counterpoint format-regarding crucial aspects of the potential links between animals and surface oxygen levels. We highlight areas where the standard discourse on this topic requires a change of course and note that several traditional arguments in this "life versus environment" debate are poorly founded. We also identify a clear need for basic research across a range of fields to disentangle the relationships between oxygen availability and emergence and diversification of animal life.
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Affiliation(s)
- Devon B Cole
- School of Earth and Atmospheric Science, Georgia Institute of Technology, Atlanta, Georgia
| | - Daniel B Mills
- Department of Geological Sciences, Stanford University, Stanford, California
| | - Douglas H Erwin
- Department of Paleobiology, National Museum of Natural History, Washington, District of Columbia
- Santa Fe Institute, Santa Fe, New Mexico
| | - Erik A Sperling
- Department of Geological Sciences, Stanford University, Stanford, California
| | - Susannah M Porter
- Department of Earth Science, University of California Santa Barbara, Santa Barbara, California
| | - Christopher T Reinhard
- School of Earth and Atmospheric Science, Georgia Institute of Technology, Atlanta, Georgia
| | - Noah J Planavsky
- Department of Geology and Geophysics, Yale University, New Haven, Connecticut
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Li L, Zhen X, Wang X, Ren Y, Hu L, Bai Y, Liu J, Shi X. Benthic trace metal fluxes in a heavily contaminated bay in China: Does the sediment become a source of metals to the water column? ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 257:113494. [PMID: 31753637 DOI: 10.1016/j.envpol.2019.113494] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/24/2019] [Accepted: 10/25/2019] [Indexed: 06/10/2023]
Abstract
Over three different seasons, seawater, porewater and sediment samples were collected from Jinzhou Bay, a previously heavily contaminated bay, to quantitatively assess the benthic flux of trace metals after a reduction in fluvial/sewage discharge for almost three decades. The spatial distribution patterns of trace metals in seawater, surface sediment, as well as the vertical distribution patterns of metals in porewater and solid phases in short sediment cores were reported. Metal concentrations in seawater and sediment all showed much higher Cd and Zn concentrations inside the Jinzhou Bay compared to the rest of Bohai Sea area. Zn, Ni, Pb and Co all had average benthic fluxes coming out of the sediments to the water column, contributing about 0.5%, 0.3%, 1.4% and 14% to their current standing stock in Jinzhou Bay. Seasonal difference was also identified in seawater and porewater, as well as in the benthic fluxes. In general, benthic fluxes and porewater concentrations all tended to be higher in summer, implying a close relationship between benthic flux and the temperature-dependent organic matter degradation process at the sediment-water interface. Currently, there are clearly still other sources, possibly fluvial/sewage discharge, as the main source of trace metals in Jinzhou Bay waters. For Cd and Cu, concentrations in the water column remain high on an annual basis indicating that sediment still acts as a sink. Conversely, for Pb, Zn, Co, and Ni, the sediment is beginning to act as a source to the water column. Although this may not yet be significant, it will become more and more important with time, and can last for hundreds to thousands of years.
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Affiliation(s)
- Li Li
- Key Laboratory of Marine Sedimentology and Environmental Geology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China; Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266061, China.
| | - Xiaotong Zhen
- Key Laboratory of Marine Sedimentology and Environmental Geology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China; The Second Engineering Company of CCCC Fourth Harbor Engineering Co. Ltd, Guangzhou, 510200, China
| | - Xiaojing Wang
- Key Laboratory of Marine Sedimentology and Environmental Geology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China
| | - Yijun Ren
- Key Laboratory of Marine Sedimentology and Environmental Geology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China
| | - Limin Hu
- Key Laboratory of Marine Sedimentology and Environmental Geology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China; Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266061, China
| | - Yazhi Bai
- Key Laboratory of Marine Sedimentology and Environmental Geology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China
| | - Jihua Liu
- Key Laboratory of Marine Sedimentology and Environmental Geology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China; Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266061, China
| | - Xuefa Shi
- Key Laboratory of Marine Sedimentology and Environmental Geology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China; Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266061, China
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34
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Wu Z, Wang S, Ji N. Phosphorus (P) release risk in lake sediment evaluated by DIFS model and sediment properties: A new sediment P release risk index (SPRRI). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 255:113279. [PMID: 31563787 DOI: 10.1016/j.envpol.2019.113279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 08/03/2019] [Accepted: 09/18/2019] [Indexed: 06/10/2023]
Abstract
A new sediment P release risk index (SPRRI) for "in-situ" phosphorus (P) release risk in lake sediment, is developed based on diffusive gradients in thin films (DGT) technique, DGT induced flux in sediments (DIFS) model and sediment properties. SPRRI includes three sub-indexes, which contain (1) the labile P pool size, (2) resupply constant (r) and desorption rate (Dspt rate) for P transfer and (3) the molar ratio between iron (Fe) in sequential extraction for sediment P by bicarbonate-dithionite (BD) and aluminum (Al) by NaOH (at 25 °C), i.e. BD(Fe)/Al[NaOH25] in sediment solid. The first sub-index considers P release from (i) sediment with NH4Cl-P+BD-P pool, i.e. the loosely sorbed P (NH4Cl-P) plus iron associated P (BD-P), or (ii) sediment with NH4Cl-P pool, respectively. The second and third sub-indexes reflect kinetic P desorption and resupply ability of solid phase, and the effect of P sequestration by Al hydroxide on P release, in turn. The inner relationship between SPRRI and sub-indexes, and their effects on P release risk are elucidated. SPRRI can be used to evaluate sediment P reactivity by five release risk ranks. For Lake Dianchi (China), P transfer dynamics, labile P pool, resupply ability and Al-P in sediment, and "external P-loading" control and affect P release risk in different regions, which is reflected by the spatial distribution map for SPRRI. The present SPRRI can be applied for lakes with (1) pH range varying from moderate acidity to weak alkalinity in waterbody and (2) NH4Cl-P or NH4Cl-P+BD-P pool in sediment solid.
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Affiliation(s)
- Zhihao Wu
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Institute of Lake Environmental, Chinese Research Academy of Environmental Sciences (CRAES), Beijing 100012, China; College of Water Sciences, Beijing Normal University, Beijing, 100875, China; Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake-Watershed, Kunming, Yunnan Province, 650034, China
| | - Shengrui Wang
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Institute of Lake Environmental, Chinese Research Academy of Environmental Sciences (CRAES), Beijing 100012, China; College of Water Sciences, Beijing Normal University, Beijing, 100875, China; Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake-Watershed, Kunming, Yunnan Province, 650034, China.
| | - Ningning Ji
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Institute of Lake Environmental, Chinese Research Academy of Environmental Sciences (CRAES), Beijing 100012, China; College of Water Sciences, Beijing Normal University, Beijing, 100875, China
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Steinsberger T, Müller B, Gerber C, Shafei B, Schmid M. Modeling sediment oxygen demand in a highly productive lake under various trophic scenarios. PLoS One 2019; 14:e0222318. [PMID: 31596854 PMCID: PMC6784980 DOI: 10.1371/journal.pone.0222318] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 08/28/2019] [Indexed: 11/19/2022] Open
Abstract
Hypolimnetic oxygen depletion in lakes is a widespread problem and is mainly controlled by the sediment oxygen uptake (SOU) and flux of reduced substances out of the sediments (Fred). Especially in eutrophic lakes, Fred may constitute a major fraction of the areal hypolimnetic mineralization rate, but its size and source is often poorly understood. Using a diagenetic reaction-transport model supported by a large data set of sediment porewater concentrations, bulk sediment core data and lake monitoring data, the behavior of Fred was simulated in eutrophic Lake Baldegg. Transient boundary conditions for the gross sedimentation of total organic carbon and for hypolimnetic O2 concentrations were applied to simulate the eutrophication and re-oligotrophication history of the lake. According to the model, Fred is dominated by methanogenesis, where up to70% to the total CH4 is produced from sediments older than 20 years deposited during the time of permanent anoxia between 1890 and 1982. An implementation of simplified seasonal variations of the upper boundary conditions showed that their consideration is not necessary for the assessment of annual average fluxes in long-term simulations. Four lake management scenarios were then implemented to investigate the future development of Fred and SOU until 2050 under different boundary conditions. A comparison of three trophic scenarios showed that further reduction of the lake productivity to at least a mesotrophic state is required to significantly decrease Fred and SOU from the present state. Conversely, a termination of artificial aeration at the present trophic state would result in high rates of organic matter deposition and a long-term increase of Fred from the sediments of Lake Baldegg.
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Affiliation(s)
- Thomas Steinsberger
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Switzerland
| | - Beat Müller
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Switzerland
| | - Christoph Gerber
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Switzerland
- Land and Water, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Glen Osmond, SA, Australia
| | - Babak Shafei
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Switzerland
- AquaNRG Consulting Inc, Houston, Texas, United States of America
| | - Martin Schmid
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Switzerland
- * E-mail:
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Haas S, Desai DK, LaRoche J, Pawlowicz R, Wallace DWR. Geomicrobiology of the carbon, nitrogen and sulphur cycles in Powell Lake: a permanently stratified water column containing ancient seawater. Environ Microbiol 2019; 21:3927-3952. [PMID: 31314947 DOI: 10.1111/1462-2920.14743] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 07/12/2019] [Accepted: 07/13/2019] [Indexed: 11/30/2022]
Abstract
We present the first geomicrobiological characterization of the meromictic water column of Powell Lake (British Columbia, Canada), a former fjord, which has been stably stratified since the last glacial period. Its deepest layers (300-350 m) retain isolated, relict seawater from that period. Fine-scale vertical profiling of the water chemistry and microbial communities allowed subdivision of the water column into distinct geomicrobiological zones. These zones were further characterized by phylogenetic and functional marker genes from amplicon and shotgun metagenome sequencing. Binning of metagenomic reads allowed the linkage of function to specific taxonomic groups. Statistical analyses (analysis of similarities, Bray-Curtis similarity) confirmed that the microbial community structure followed closely the geochemical zonation. Yet, our characterization of the genetic potential relevant to carbon, nitrogen and sulphur cycling of each zone revealed unexpected features, including potential for facultative anaerobic methylotrophy, nitrogen fixation despite high ammonium concentrations and potential micro-aerobic nitrifiers within the chemocline. At the oxic-suboxic interface, facultative anaerobic potential was found in the widespread freshwater lineage acI (Actinobacteria), suggesting intriguing ecophysiological similarities to the marine SAR11. Evolutionary divergent lineages among diverse phyla were identified in the ancient seawater zone and may indicate novel adaptations to this unusual environment.
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Affiliation(s)
- Sebastian Haas
- Department of Oceanography, Dalhousie University, 1355 Oxford Street, Halifax, Nova Scotia, Canada
| | - Dhwani K Desai
- Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, Nova Scotia, Canada
| | - Julie LaRoche
- Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, Nova Scotia, Canada
| | - Rich Pawlowicz
- Department of Earth and Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver, British Columbia, Canada
| | - Douglas W R Wallace
- Department of Oceanography, Dalhousie University, 1355 Oxford Street, Halifax, Nova Scotia, Canada
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A 1-Dimensional Sympagic–Pelagic–Benthic Transport Model (SPBM): Coupled Simulation of Ice, Water Column, and Sediment Biogeochemistry, Suitable for Arctic Applications. WATER 2019. [DOI: 10.3390/w11081582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Marine biogeochemical processes can strongly interact with processes occurring in adjacent ice and sediments. This is especially likely in areas with shallow water and frequent ice cover, both of which are common in the Arctic. Modeling tools are therefore required to simulate coupled biogeochemical systems in ice, water, and sediment domains. We developed a 1D sympagic–pelagic–benthic transport model (SPBM) which uses input from physical model simulations to describe hydrodynamics and ice growth and modules from the Framework for Aquatic Biogeochemical Models (FABM) to construct a user-defined biogeochemical model. SPBM coupled with a biogeochemical model simulates the processes of vertical diffusion, sinking/burial, and biogeochemical transformations within and between the three domains. The potential utility of SPBM is demonstrated herein with two test runs using modules from the European regional seas ecosystem model (ERSEM) and the bottom-redox model biogeochemistry (BROM-biogeochemistry). The first run simulates multiple phytoplankton functional groups inhabiting the ice and water domains, while the second simulates detailed redox biogeochemistry in the ice, water, and sediments. SPBM is a flexible tool for integrated simulation of ice, water, and sediment biogeochemistry, and as such may help in producing well-parameterized biogeochemical models for regions with strong sympagic–pelagic–benthic interactions.
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Louca S, Scranton MI, Taylor GT, Astor YM, Crowe SA, Doebeli M. Circumventing kinetics in biogeochemical modeling. Proc Natl Acad Sci U S A 2019; 116:11329-11338. [PMID: 31097587 PMCID: PMC6561284 DOI: 10.1073/pnas.1819883116] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Microbial metabolism drives biogeochemical fluxes in virtually every ecosystem. Modeling these fluxes is challenged by the incredible diversity of microorganisms, whose kinetic parameters are largely unknown. In poorly mixed systems, such as stagnant water columns or sediments, however, long-term bulk microbial metabolism may become limited by physical transport rates of substrates across space. Here we mathematically show that under these conditions, biogeochemical fluxes are largely predictable based on the system's transport properties, chemical boundary conditions, and the stoichiometry of metabolic pathways, regardless of the precise kinetics of the resident microorganisms. We formalize these considerations into a predictive modeling framework and demonstrate its use for the Cariaco Basin subeuphotic zone, one of the largest anoxic marine basins worldwide. Using chemical concentration data solely from the upper boundary (depth 180 m) and lower boundary (depth 900 m), but without a priori knowledge of metabolite fluxes, chemical depth profiles, kinetic parameters, or microbial species composition, we predict the concentrations and vertical fluxes of biologically important substances, including oxygen, nitrate, hydrogen sulfide, and ammonium, across the entire considered depth range (180-900 m). Our predictions largely agree with concentration measurements over a period of 14 years ([Formula: see text] = 0.78-0.92) and become particularly accurate during a period where the system was near biogeochemical steady state (years 2007-2009, [Formula: see text] = 0.86-0.95). Our work enables geobiological predictions for a large class of ecosystems without knowledge of kinetic parameters or geochemical depth profiles. Conceptually, our work provides a possible explanation for the decoupling between microbial species composition and bulk metabolic function, observed in various ecosystems.
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Affiliation(s)
- Stilianos Louca
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403;
- Department of Biology, University of Oregon, Eugene, OR 97403
| | - Mary I Scranton
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794
| | - Gordon T Taylor
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794
| | - Yrene M Astor
- Estación de Investigaciones Marinas de Margarita, Fundación La Salle de Ciencias Naturales, Punta de Piedras, Estado Nueva Esparta, Venezuela
- Institute for Marine Remote Sensing, University of South Florida, Tampa, FL 33701
| | - Sean A Crowe
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
- Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Michael Doebeli
- Biodiversity Research Centre, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- Department of Mathematics, University of British Columbia, Vancouver, BC V6T 1Z2, Canada
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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Sturm A, Fowle DA, Jones C, Leslie K, Nomosatryo S, Henny C, Canfield DE, Crowe SA. Rates and pathways of CH 4 oxidation in ferruginous Lake Matano, Indonesia. GEOBIOLOGY 2019; 17:294-307. [PMID: 30593722 DOI: 10.1111/gbi.12325] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 10/16/2018] [Accepted: 10/30/2018] [Indexed: 06/09/2023]
Abstract
This study evaluates rates and pathways of methane (CH4 ) oxidation and uptake using 14 C-based tracer experiments throughout the oxic and anoxic waters of ferruginous Lake Matano. Methane oxidation rates in Lake Matano are moderate (0.36 nmol L-1 day-1 to 117 μmol L-1 day-1 ) compared to other lakes, but are sufficiently high to preclude strong CH4 fluxes to the atmosphere. In addition to aerobic CH4 oxidation, which takes place in Lake Matano's oxic mixolimnion, we also detected CH4 oxidation in Lake Matano's anoxic ferruginous waters. Here, CH4 oxidation proceeds in the apparent absence of oxygen (O2 ) and instead appears to be coupled to some as yet uncertain combination of nitrate ( NO 3 - ), nitrite ( NO 2 - ), iron (Fe) or manganese (Mn), or sulfate ( SO 4 2 - ) reduction. Throughout the lake, the fraction of CH4 carbon that is assimilated vs. oxidized to carbon dioxide (CO2 ) is high (up to 93%), indicating extensive CH4 conversion to biomass and underscoring the importance of CH4 as a carbon and energy source in Lake Matano and potentially other ferruginous or low productivity environments.
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Affiliation(s)
- Arne Sturm
- Department of Geology, University of Kansas, Lawrence, Kansas
| | - David A Fowle
- Department of Geology, University of Kansas, Lawrence, Kansas
| | - CarriAyne Jones
- Department of Microbiology and Immunology and Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia, Canada
- Nordic Center for Earth Evolution, Institute of Biology, University of Southern Denmark, Odensee, Denmark
| | - Karla Leslie
- Department of Geology, University of Kansas, Lawrence, Kansas
| | - Sulung Nomosatryo
- Research Center for Limnology, Indonesian Institute of Sciences (LIPI), Cibinong-Bogor, Indonesia
| | - Cynthia Henny
- Research Center for Limnology, Indonesian Institute of Sciences (LIPI), Cibinong-Bogor, Indonesia
| | - Donald E Canfield
- Nordic Center for Earth Evolution, Institute of Biology, University of Southern Denmark, Odensee, Denmark
| | - Sean A Crowe
- Department of Microbiology and Immunology and Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia, Canada
- Nordic Center for Earth Evolution, Institute of Biology, University of Southern Denmark, Odensee, Denmark
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Environmental filtering determines family-level structure of sulfate-reducing microbial communities in subsurface marine sediments. ISME JOURNAL 2019; 13:1920-1932. [PMID: 30894690 DOI: 10.1038/s41396-019-0387-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/22/2019] [Accepted: 02/28/2019] [Indexed: 01/09/2023]
Abstract
Recent work has shown that subsurface microbial communities assemble by selective survival of surface community members during sediment burial, but it remains unclear to what extent the compositions of the subsurface communities are a product of their founding population at the sediment surface or of the changing geochemical conditions during burial. Here we investigate this question for communities of sulfate-reducing microorganisms (SRMs). We collected marine sediment samples from the upper 3-5 m at four geochemically contrasting sites in the Skagerrak and Baltic Sea and measured SRM abundance (quantitative PCR of dsrB), metabolic activity (radiotracer rate measurements), and community composition (Illumina sequencing of dsrB amplicons). These data showed that SRM abundance, richness, and phylogenetic clustering as determined by the nearest taxon index peaked below the bioturbation zone and above the depth of sulfate depletion. Minimum cell-specific rates of sulfate reduction did not vary substantially between sites. SRM communities at different sites were best distinguished based on their composition of amplicon sequence variants (ASVs), while communities in different geochemical zones were best distinguished based on their composition of SRM families. This demonstrates environmental filtering of SRM communities in sediment while a site-specific fingerprint of the founding community is retained.
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41
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Labrado AL, Brunner B, Bernasconi SM, Peckmann J. Formation of Large Native Sulfur Deposits Does Not Require Molecular Oxygen. Front Microbiol 2019; 10:24. [PMID: 30740094 PMCID: PMC6355691 DOI: 10.3389/fmicb.2019.00024] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 01/09/2019] [Indexed: 01/05/2023] Open
Abstract
Large native (i.e., elemental) sulfur deposits can be part of caprock assemblages found on top of or in lateral position to salt diapirs and as stratabound mineralization in gypsum and anhydrite lithologies. Native sulfur is formed when hydrocarbons come in contact with sulfate minerals in presence of liquid water. The prevailing model for native sulfur formation in such settings is that sulfide produced by sulfate-reducing bacteria is oxidized to zero-valent sulfur in presence of molecular oxygen (O2). Although possible, such a scenario is problematic because: (1) exposure to oxygen would drastically decrease growth of microbial sulfate-reducing organisms, thereby slowing down sulfide production; (2) on geologic timescales, excess supply with oxygen would convert sulfide into sulfate rather than native sulfur; and (3) to produce large native sulfur deposits, enormous amounts of oxygenated water would need to be brought in close proximity to environments in which ample hydrocarbon supply sustains sulfate reduction. However, sulfur stable isotope data from native sulfur deposits emplaced at a stage after the formation of the host rocks indicate that the sulfur was formed in a setting with little solute exchange with the ambient environment and little supply of dissolved oxygen. We deduce that there must be a process for the formation of native sulfur in absence of an external oxidant for sulfide. We hypothesize that in systems with little solute exchange, sulfate-reducing organisms, possibly in cooperation with other anaerobic microbial partners, drive the formation of native sulfur deposits. In order to cope with sulfide stress, microbes may shift from harmful sulfide production to non-hazardous native sulfur production. We propose four possible mechanisms as a means to form native sulfur: (1) a modified sulfate reduction process that produces sulfur compounds with an intermediate oxidation state, (2) coupling of sulfide oxidation to methanogenesis that utilizes methylated compounds, acetate or carbon dioxide, (3) ammonium oxidation coupled to sulfate reduction, and (4) sulfur comproportionation of sulfate and sulfide. We show these reactions are thermodynamically favorable and especially useful in environments with multiple stressors, such as salt and dissolved sulfide, and provide evidence that microbial species functioning in such environments produce native sulfur. Integrating these insights, we argue that microbes may form large native sulfur deposits in absence of light and external oxidants such as O2, nitrate, and metal oxides. The existence of such a process would not only explain enigmatic occurrences of native sulfur in the geologic record, but also provide an explanation for cryptic sulfur and carbon cycling beneath the seabed.
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Affiliation(s)
- Amanda L. Labrado
- Department of Geological Sciences, The University of Texas at El Paso, El Paso, TX, United States
| | - Benjamin Brunner
- Department of Geological Sciences, The University of Texas at El Paso, El Paso, TX, United States
| | | | - Jörn Peckmann
- Centrum für Erdsystemforschung und Nachhaltigkeit, Universität Hamburg, Hamburg, Germany
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Liu X, Pan J, Liu Y, Li M, Gu JD. Diversity and distribution of Archaea in global estuarine ecosystems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 637-638:349-358. [PMID: 29753224 DOI: 10.1016/j.scitotenv.2018.05.016] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/01/2018] [Accepted: 05/02/2018] [Indexed: 05/12/2023]
Abstract
Estuarine ecosystem is a unique geographical transitional zone between freshwater and seawater, harboring a wide range of microbial communities including Archaea. Although a large number of Archaea have been detected in such ecosystem, the global patterns in archaeal diversity and distribution are extremely scarce. To bridge this gap, we carried out a comprehensive survey of archaeal communities using ca. 4000 publicly available archaeal 16S rRNA gene sequences (>300 bp) collected from 24 estuaries in different latitude regions. These sequences were divided into 1450 operational taxonomic units (OTUs) at 97% identity, suggesting a high biodiversity that increased gradually from the high- to low-latitude estuaries. Phylogenetic analysis showed that estuarine ecosystem was a large biodiversity pool of Archaea that was mainly composed of 12 phyla. Among them, the predominant groups were Bathyarchaeota, Euryarchaeota and Thaumarchaeota. Interestingly, archaeal distribution demonstrated a geographical differentiation in that Thaumarchaeota was dominated in the low-latitude estuaries, Bathyarchaeota in the mid-latitude estuaries, and Euryarchaeota in the high-latitude estuaries, respectively. Furthermore, the majority of the most abundant 20 OTUs demonstrated an overrepresented or underrepresented distribution pattern in some specific estuaries or latitude regions while a few were evenly distributed throughout the estuaries. This pattern indicates a potential selectivity of geographical distribution. In addition, the analysis of environmental parameters suggested that latitude would be one of the major factors driving the distribution of archaeal communities in estuarine ecosystem. This study profiles a clear framework on the diversity and distribution of Archaea in the global estuarine ecosystem and explores the general environmental factors that influence these patterns. Our findings constitute an important part of the exploration of the global ecology of Archaea.
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Affiliation(s)
- Xiaobo Liu
- Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, Faculty of Science, The University of Hong Kong, Pokfulam Road, Hong Kong, People's Republic of China
| | - Jie Pan
- Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, People's Republic of China
| | - Yang Liu
- Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, People's Republic of China
| | - Meng Li
- Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, People's Republic of China.
| | - Ji-Dong Gu
- Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, Faculty of Science, The University of Hong Kong, Pokfulam Road, Hong Kong, People's Republic of China; State Key Laboratory in Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong, People's Republic of China.
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Bridou R, Rodriguez-Gonzalez P, Stoichev T, Amouroux D, Monperrus M, Navarro P, Tessier E, Guyoneaud R. Methylation and dealkykation of tin compounds by sulfate- and nitrate-reducing bacteria. CHEMOSPHERE 2018; 208:871-879. [PMID: 30068030 DOI: 10.1016/j.chemosphere.2018.06.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 05/31/2018] [Accepted: 06/04/2018] [Indexed: 06/08/2023]
Abstract
In this study, axenic cultures of sulfate-reducing (SRB) and nitrate-reducing (NRB) bacteria were examined for their ability to methylate inorganic tin and to methylate or dealkylate butyltin compounds. Environmentally relevant concentrations of natural abundance tributyltin (TBT) and 116Sn-enriched inorganic tin were added to bacterial cultures to identify bacterial-mediated methylation and dealkylation reactions. The results show that none of the Desulfovibrio strains tested was able to induce any transformation process. In contrast, Desulfobulbus propionicus strain DSM-6523 degraded TBT either under sulfidogenic or non-sulfidogenic conditions. In addition, it was able to alkykate 116Sn-enriched inorganic tin leading to the formation of more toxic dimethyltin and trimethyltin. A similar capacity was observed for incubations of Pseudomonas but with a much greater dealkykation of TBT. As such, Pseudomonas sp. ADR42 degraded 61% of the initial TBT under aerobic conditions and 35% under nitrate-reducing conditions. This is the first work reporting a simultaneous TBT degradation and a methylation of both inorganic tin species and TBT dealkykation products by SRB and NRB under anoxic conditions. These reactions are environmentally relevant as they can control the mobility of these compounds in aquatic ecosystems; as well as their toxicity toward resident organisms.
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Affiliation(s)
- Romain Bridou
- CNRS / Univ. Pau & Pays Adour, Institut des Sciences Analytiques et de Physico-chimie pour L'Environnement et les Matériaux, UMR5254, 64000, Pau, France
| | - Pablo Rodriguez-Gonzalez
- CNRS / Univ. Pau & Pays Adour, Institut des Sciences Analytiques et de Physico-chimie pour L'Environnement et les Matériaux, UMR5254, 64000, Pau, France
| | - Teodor Stoichev
- CNRS / Univ. Pau & Pays Adour, Institut des Sciences Analytiques et de Physico-chimie pour L'Environnement et les Matériaux, UMR5254, 64000, Pau, France
| | - David Amouroux
- CNRS / Univ. Pau & Pays Adour, Institut des Sciences Analytiques et de Physico-chimie pour L'Environnement et les Matériaux, UMR5254, 64000, Pau, France.
| | - Mathilde Monperrus
- CNRS / Univ. Pau & Pays Adour, Institut des Sciences Analytiques et de Physico-chimie pour L'Environnement et les Matériaux, UMR5254, 64000, Pau, France
| | - Patricia Navarro
- CNRS / Univ. Pau & Pays Adour, Institut des Sciences Analytiques et de Physico-chimie pour L'Environnement et les Matériaux, UMR5254, 64000, Pau, France
| | - Emmanuel Tessier
- CNRS / Univ. Pau & Pays Adour, Institut des Sciences Analytiques et de Physico-chimie pour L'Environnement et les Matériaux, UMR5254, 64000, Pau, France
| | - Rémy Guyoneaud
- CNRS / Univ. Pau & Pays Adour, Institut des Sciences Analytiques et de Physico-chimie pour L'Environnement et les Matériaux, UMR5254, 64000, Pau, France.
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Jochum LM, Schreiber L, Marshall IPG, Jørgensen BB, Schramm A, Kjeldsen KU. Single-Cell Genomics Reveals a Diverse Metabolic Potential of Uncultivated Desulfatiglans-Related Deltaproteobacteria Widely Distributed in Marine Sediment. Front Microbiol 2018; 9:2038. [PMID: 30233524 PMCID: PMC6129605 DOI: 10.3389/fmicb.2018.02038] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 08/13/2018] [Indexed: 11/13/2022] Open
Abstract
Desulfatiglans-related organisms comprise one of the most abundant deltaproteobacterial lineages in marine sediments where they occur throughout the sediment column in a gradient of increasing sulfate and organic carbon limitation with depth. Characterized Desulfatiglans isolates are dissimilatory sulfate reducers able to grow by degrading aromatic hydrocarbons. The ecophysiology of environmental Desulfatiglans-populations is poorly understood, however, possibly utilization of aromatic compounds may explain their predominance in marine subsurface sediments. We sequenced and analyzed seven Desulfatiglans-related single-cell genomes (SAGs) from Aarhus Bay sediments to characterize their metabolic potential with regard to aromatic compound degradation and energy metabolism. The average genome assembly size was 1.3 Mbp and completeness estimates ranged between 20 and 50%. Five of the SAGs (group 1) originated from the sulfate-rich surface part of the sediment while two (group 2) originated from sulfate-depleted subsurface sediment. Based on 16S rRNA gene amplicon sequencing group 2 SAGs represent the more frequent types of Desulfatiglans-populations in Aarhus Bay sediments. Genes indicative of aromatic compound degradation could be identified in both groups, but the two groups were metabolically distinct with regard to energy conservation. Group 1 SAGs carry a full set of genes for dissimilatory sulfate reduction, whereas the group 2 SAGs lacked any genetic evidence for sulfate reduction. The latter may be due to incompleteness of the SAGs, but as alternative energy metabolisms group 2 SAGs carry the genetic potential for growth by acetogenesis and fermentation. Group 1 SAGs encoded reductive dehalogenase genes, allowing them to access organohalides and possibly conserve energy by their reduction. Both groups possess sulfatases unlike their cultured relatives allowing them to utilize sulfate esters as source of organic carbon and sulfate. In conclusion, the uncultivated marine Desulfatiglans populations are metabolically diverse, likely reflecting different strategies for coping with energy and sulfate limitation in the subsurface seabed.
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Affiliation(s)
- Lara M Jochum
- Center for Geomicrobiology, Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Lars Schreiber
- Center for Geomicrobiology, Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Ian P G Marshall
- Center for Geomicrobiology, Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Bo B Jørgensen
- Center for Geomicrobiology, Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Andreas Schramm
- Center for Geomicrobiology, Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Kasper U Kjeldsen
- Center for Geomicrobiology, Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
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45
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Function and functional redundancy in microbial systems. Nat Ecol Evol 2018; 2:936-943. [PMID: 29662222 DOI: 10.1038/s41559-018-0519-1] [Citation(s) in RCA: 663] [Impact Index Per Article: 110.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Accepted: 02/26/2018] [Indexed: 11/08/2022]
Abstract
Microbial communities often exhibit incredible taxonomic diversity, raising questions regarding the mechanisms enabling species coexistence and the role of this diversity in community functioning. On the one hand, many coexisting but taxonomically distinct microorganisms can encode the same energy-yielding metabolic functions, and this functional redundancy contrasts with the expectation that species should occupy distinct metabolic niches. On the other hand, the identity of taxa encoding each function can vary substantially across space or time with little effect on the function, and this taxonomic variability is frequently thought to result from ecological drift between equivalent organisms. Here, we synthesize the powerful paradigm emerging from these two patterns, connecting the roles of function, functional redundancy and taxonomy in microbial systems. We conclude that both patterns are unlikely to be the result of ecological drift, but are inevitable emergent properties of open microbial systems resulting mainly from biotic interactions and environmental and spatial processes.
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46
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Van Den Berghe MD, Jamieson HE, Palmer MJ. Arsenic mobility and characterization in lakes impacted by gold ore roasting, Yellowknife, NWT, Canada. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 234:630-641. [PMID: 29223820 DOI: 10.1016/j.envpol.2017.11.062] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 11/11/2017] [Accepted: 11/19/2017] [Indexed: 05/26/2023]
Abstract
The controls on the mobility and fate of arsenic in lakes impacted by historical gold ore roasting in northern Canada have been examined. A detailed characterization of arsenic solid and aqueous phases in lake waters, lake sediments and sediment porewaters as well as surrounding soils was conducted in three small lakes (<200ha) downwind and within 5 km of the historic mining and roasting operations of Giant Mine (Northwest Territories). These lakes are marked by differing limnological characteristics such as area, depth and organic content. Radiometric age-dating shows that the occurrence of arsenic trioxide in lake sediments coincides with the regional onset of roasting activities. Quantification by advanced electron microscopy shows that arsenic trioxide accounts for up to 6 wt% of the total arsenic in sediments. The bulk (>80 wt%) of arsenic is contained in the form of secondary sulphide precipitates, with iron oxy-hydroxides hosting a minimal amount of arsenic (<1 wt%). Soluble arsenic trioxide particles act as the primary source of arsenic into sediment porewaters. Dissolved arsenic in reducing porewaters both precipitates in-situ as secondary sulphides, and diffuses upwards into the overlying lake waters. Geogenic arsenic phases are present in sediments in low concentrations and are not considered a significant source of arsenic to porewaters or lake waters. Sediment-water interface diffusive flux calculations suggest that the diffusion of dissolved arsenic from porewaters, combined with lake water residence time, are the predominant mechanisms controlling arsenic concentrations in lake waters.
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Affiliation(s)
- Martin D Van Den Berghe
- Department of Geological Sciences and Geological Engineering, Queen's University, 36 Union St., Kingston, ON K7L 3N6, Canada; Department of Earth Sciences, University of Southern California, 3651 Trousdale Pkwy, Los Angeles, CA 90089, USA.
| | - Heather E Jamieson
- Department of Geological Sciences and Geological Engineering, Queen's University, 36 Union St., Kingston, ON K7L 3N6, Canada.
| | - Michael J Palmer
- Cumulative Impact Monitoring Program, Environment and Natural Resources, Government of the Northwest Territories, 5102 50(th) Ave., Yellowknife, NWT, Canada; Department of Geography and Environmental Studies, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada.
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47
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Zhou Z, Meng H, Liu Y, Gu JD, Li M. Stratified Bacterial and Archaeal Community in Mangrove and Intertidal Wetland Mudflats Revealed by High Throughput 16S rRNA Gene Sequencing. Front Microbiol 2017; 8:2148. [PMID: 29163432 PMCID: PMC5673634 DOI: 10.3389/fmicb.2017.02148] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 10/20/2017] [Indexed: 12/02/2022] Open
Abstract
The stratified distribution of bacterial and archaeal communities has been detected in many sediment profiles from various natural environments. A better understanding of microbial composition and diversity pattern in coastal mangrove wetlands in relation to physicochemical and spatial-temporal influences could provide more insights into the ecological functions of microbes in coastal wetlands. In this study, seasonal variations of microbial communities within sediment profiles from two sediment types (mangrove forest and intertidal mudflats) at three sampling locations in coastal Mai Po wetland were characterized using MiSeq high throughput sequencing and 16S rRNA quantitative PCR methods. Bacterial 16S rRNA gene abundance showed clear decreasing trends with increasing depth for all sites, seasonality and sediment types. There is a weak seasonal dynamic of bacterial and archaeal community abundance in both seasons. Seasonality imposed more influence on the beta diversity pattern of bacterial community than archaeal community. The five most abundant phyla within bacterial and archaeal community remain stable between two distinctive seasons. Sediment depth and seasonality are the most influential factors affecting bacterial community composition and diversity. The pH is the most influential factor on shaping the archaeal community. Stratified distribution of bacterial community including aerobic and anaerobic bacterial taxa is largely represented in the surface layers and the subsurface layers, respectively. For archaeal stratification, Thaumarchaeota Marine Group I is the dominant member in surface sediments while Bathyarchaeota and MBG-B dominate in subsurface sediments. Such stratified distribution patterns are irrespective of sediment types, sampling locations or seasonality, but significantly correlated to the sediment depth, which might be shaped by oxygen availability and the distribution of other terminal electron accepters along the depth profile.
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Affiliation(s)
- Zhichao Zhou
- Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, University of Hong Kong, Pokfulam, Hong Kong
| | - Han Meng
- Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, University of Hong Kong, Pokfulam, Hong Kong
| | - Yang Liu
- Institute for Advanced Study, Shenzhen University, Shenzhen, China
| | - Ji-Dong Gu
- Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, University of Hong Kong, Pokfulam, Hong Kong
| | - Meng Li
- Institute for Advanced Study, Shenzhen University, Shenzhen, China
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48
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Wasmund K, Mußmann M, Loy A. The life sulfuric: microbial ecology of sulfur cycling in marine sediments. ENVIRONMENTAL MICROBIOLOGY REPORTS 2017; 9:323-344. [PMID: 28419734 PMCID: PMC5573963 DOI: 10.1111/1758-2229.12538] [Citation(s) in RCA: 175] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Almost the entire seafloor is covered with sediments that can be more than 10 000 m thick and represent a vast microbial ecosystem that is a major component of Earth's element and energy cycles. Notably, a significant proportion of microbial life in marine sediments can exploit energy conserved during transformations of sulfur compounds among different redox states. Sulfur cycling, which is primarily driven by sulfate reduction, is tightly interwoven with other important element cycles (carbon, nitrogen, iron, manganese) and therefore has profound implications for both cellular- and ecosystem-level processes. Sulfur-transforming microorganisms have evolved diverse genetic, metabolic, and in some cases, peculiar phenotypic features to fill an array of ecological niches in marine sediments. Here, we review recent and selected findings on the microbial guilds that are involved in the transformation of different sulfur compounds in marine sediments and emphasise how these are interlinked and have a major influence on ecology and biogeochemistry in the seafloor. Extraordinary discoveries have increased our knowledge on microbial sulfur cycling, mainly in sulfate-rich surface sediments, yet many questions remain regarding how sulfur redox processes may sustain the deep-subsurface biosphere and the impact of organic sulfur compounds on the marine sulfur cycle.
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Affiliation(s)
- Kenneth Wasmund
- Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, Research Network “Chemistry meets Microbiology”University of ViennaAlthanstrasse 14ViennaA‐1090Austria
- Austrian Polar Research InstituteViennaAustria
| | - Marc Mußmann
- Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, Research Network “Chemistry meets Microbiology”University of ViennaAlthanstrasse 14ViennaA‐1090Austria
| | - Alexander Loy
- Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, Research Network “Chemistry meets Microbiology”University of ViennaAlthanstrasse 14ViennaA‐1090Austria
- Austrian Polar Research InstituteViennaAustria
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49
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Bowyer F, Wood RA, Poulton SW. Controls on the evolution of Ediacaran metazoan ecosystems: A redox perspective. GEOBIOLOGY 2017; 15:516-551. [PMID: 28387043 PMCID: PMC5485040 DOI: 10.1111/gbi.12232] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 01/25/2017] [Indexed: 05/26/2023]
Abstract
A growing number of detailed geochemical studies of Ediacaran (635-541 Ma) marine successions have provided snapshots into the redox environments that played host to the earliest known metazoans. Whilst previous compilations have focused on the global evolution of Ediacaran water column redox chemistry, the inherent heterogeneity evident in palaeogeographically distinct environments demands a more dissected approach to better understand the nature, interactions and evolution of extrinsic controls on the development of early macrobenthic ecosystems. Here, we review available data of local-scale redox conditions within a palaeogeographic and sequence stratigraphic framework, to explore the mechanisms controlling water column redox conditions and their potential impact on the record of metazoans. The openly connected Laurentian margin, North America (632-540 Ma) and Nama basin, Namibia (550-538 Ma), and the variably restricted Yangtze Block, South China (635-520 Ma), show continued redox instability after the first fossil evidence for metazoans. This may support opportunistic benthic colonisation during periods of transient oxygenation amidst episodic upwelling of anoxic waters beneath a very shallow, fluctuating chemocline. The first skeletal metazoans appeared under conditions of continued redox stratification, such as those which characterise the Dengying Formation of the Yangtze Block and the Kuibis Subgroup of the Nama basin. Current data, however, suggests that successful metazoan reef-building demanded more persistent oxia. We propose that cratonic positioning and migration throughout the Ediacaran Period, in combination with gradually increasing dissolved oxygen loading, may have provided a first-order control on redox evolution through regulating circulation mechanisms in the Mirovian Ocean. Some unrestricted lower slope environments from mid-high latitudes benefited from sustained oxygenation via downwelling, whilst transit of isolated cratons towards more equatorial positions stifled pervasive ventilation either through ineffective surface ocean mixing, Ekman-induced upwelling, elevated surface ocean productivity or a combination of these processes.
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Affiliation(s)
- F Bowyer
- School of Geosciences, University of Edinburgh, Edinburgh, UK
| | - R A Wood
- School of Geosciences, University of Edinburgh, Edinburgh, UK
| | - S W Poulton
- School of Earth and Environment, University of Leeds, Leeds, UK
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50
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Louca S, Jacques SMS, Pires APF, Leal JS, González AL, Doebeli M, Farjalla VF. Functional structure of the bromeliad tank microbiome is strongly shaped by local geochemical conditions. Environ Microbiol 2017; 19:3132-3151. [PMID: 28488752 DOI: 10.1111/1462-2920.13788] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 04/24/2017] [Indexed: 11/27/2022]
Abstract
Phytotelmata in tank-forming Bromeliaceae plants are regarded as potential miniature models for aquatic ecology, but detailed investigations of their microbial communities are rare. Hence, the biogeochemistry in bromeliad tanks remains poorly understood. Here we investigate the structure of bacterial and archaeal communities inhabiting the detritus within the tanks of two bromeliad species, Aechmea nudicaulis and Neoregelia cruenta, from a Brazilian sand dune forest. We used metagenomic sequencing for functional community profiling and 16S sequencing for taxonomic profiling. We estimated the correlation between functional groups and various environmental variables, and compared communities between bromeliad species. In all bromeliads, microbial communities spanned a metabolic network adapted to oxygen-limited conditions, including all denitrification steps, ammonification, sulfate respiration, methanogenesis, reductive acetogenesis and anoxygenic phototrophy. Overall, CO2 reducers dominated in abundance over sulfate reducers, and anoxygenic phototrophs largely outnumbered oxygenic photoautotrophs. Functional community structure correlated strongly with environmental variables, between and within a single bromeliad species. Methanogens and reductive acetogens correlated with detrital volume and canopy coverage, and exhibited higher relative abundances in N. cruenta. A comparison of bromeliads to freshwater lake sediments and soil from around the world, revealed stark differences in terms of taxonomic as well as functional microbial community structure.
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Affiliation(s)
- Stilianos Louca
- Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada.,Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Saulo M S Jacques
- Department of Ecology, Biology Institute, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Programa de Pós-Graduação em Ecologia e Evolução, Universidade Estadual do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Aliny P F Pires
- Department of Ecology, Biology Institute, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Juliana S Leal
- Department of Ecology, Biology Institute, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Programa de Pós-Graduação em Ecologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Angélica L González
- Biology Department & Center for Computational & Integrative Biology, Rutgers University, Camden, NJ, USA
| | - Michael Doebeli
- Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada.,Department of Zoology, University of British Columbia, Vancouver, BC, Canada.,Department of Mathematics, University of British Columbia, Vancouver, BC, Canada
| | - Vinicius F Farjalla
- Department of Ecology, Biology Institute, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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