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Song K, Wang S, Xu X, Ma J, Yang Y, Zeng Y, Li J, Zhou X, Zhou Y. Benthic clade II-type nitrous oxide reducers suppress nitrous oxide emissions in shallow lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 931:172908. [PMID: 38697552 DOI: 10.1016/j.scitotenv.2024.172908] [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: 02/22/2024] [Revised: 04/07/2024] [Accepted: 04/29/2024] [Indexed: 05/05/2024]
Abstract
Shallow lakes, recognized as hotspots for nitrogen cycling, contribute to the emission of the potent greenhouse gas nitrous oxide (N2O), but the current emission estimates for this gas have a high degree of uncertainty. However, the role of N2O-reducing bacteria (N2ORB) as N2O sinks and their contribution to N2O reduction in aquatic ecosystems in response to N2O dynamics have not been determined. Here, we investigated the N2O dynamics and microbial processes in the nitrogen cycle, which included both N2O production and consumption, in five shallow lakes spanning approximately 500 km. The investigated sites exhibited N2O oversaturation, with excess dissolved N2O concentrations (ΔN2O) ranging from 0.55 ± 0.61 to 53.17 ± 15.75 nM. Sediment-bound N2O (sN2O) was significantly positively correlated with the nitrate concentration in the overlying water (p < 0.05), suggesting that nitrate accumulation contributes to benthic N2O generation. High N2O consumption activity (RN2O) corresponded to low ΔN2O. In addition, a significant negative correlation was found between RN2O and nir/nosZ, showing that bacteria encoding nosZ contributed to N2O consumption in the benthic sediments. Redundancy analysis indicated that benthic functional genes effectively reflected the variations in RN2O and ∆N2O. qPCR analysis revealed that the clade II nosZ gene was more sensitive to ΔN2O than the clade I nosZ gene. Furthermore, four novel genera of potential nondenitrifying N2ORB were identified based on metagenome-assembled genome analysis. These genera, which are affiliated with clade II, lack genes responsible for N2O production. Collectively, benthic N2ORB, especially for clade II-type N2ORB, harnesses N2O consumption activity leading to low N2O emissions from shallow lakes. This study advances our knowledge of the role of benthic clade II-type N2ORB in regulating N2O emissions in shallow lakes.
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Affiliation(s)
- Kang Song
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Siyu Wang
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Xiaoguang Xu
- School of Environment, Nanjing Normal University, Nanjing 210023, China
| | - Jie Ma
- Ministry of Ecology and Environment, Nanjing Institute of Environment Sciences, Nanjing 210042, China
| | - Yuxuan Yang
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China; School of Environment, Nanjing Normal University, Nanjing 210023, China
| | - Yuli Zeng
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Jining Li
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Xiaohong Zhou
- School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Yiwen Zhou
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China.
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2
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Intrator N, Jayakumar A, Ward BB. Aquatic nitrous oxide reductase gene ( nosZ) phylogeny and environmental distribution. Front Microbiol 2024; 15:1407573. [PMID: 38835481 PMCID: PMC11148229 DOI: 10.3389/fmicb.2024.1407573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 05/06/2024] [Indexed: 06/06/2024] Open
Abstract
Nitrous oxide (N2O) is a potent greenhouse gas and a major cause of ozone depletion. One-third of atmospheric N2O originates in aquatic environments. Reduction of N2O to dinitrogen gas (N2) requires the nitrous oxide reductase enzyme, which is encoded by the gene nosZ. Organisms that contain nosZ are the only known biological sinks of N2O and are found in diverse genera and a wide range of environments. The two clades of nosZ (Clade I and II) contain great diversity, making it challenging to study the population structure and distribution of nosZ containing organisms in the environment. A database of over 11,000 nosZ sequences was compiled from NCBI (representing diverse aquatic environments) and unpublished sequences and metagenomes (primarily from oxygen minimum zones, OMZs, where N2O levels are often elevated). Sequences were clustered into archetypes based on DNA and amino acid sequence identity and their clade, phylogeny, and environmental source were determined. Further analysis of the source and environmental distribution of the sequences showed strong habitat separation between clades and phylogeny. Although there are more Clade I nosZ genes in the compilation, Clade II is more diverse phylogenetically and has a wider distribution across environmental sources. On the other hand, Clade I nosZ genes are predominately found within marine sediment and are primarily from the phylum Pseudonomonadota. The majority of the sequences analyzed from marine OMZs represented distinct phylotypes between different OMZs showing that the nosZ gene displays regional and environmental separation. This study expands the known diversity of nosZ genes and provides a clearer picture of how the clades and phylogeny of nosZ organisms are distributed across diverse environments.
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Affiliation(s)
- Naomi Intrator
- Department of Geosciences, Princeton University, Princeton, NJ, United States
| | - Amal Jayakumar
- Department of Geosciences, Princeton University, Princeton, NJ, United States
| | - Bess B Ward
- Department of Geosciences, Princeton University, Princeton, NJ, United States
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Hunt KA, Carr AV, Otwell AE, Valenzuela JJ, Walker KS, Dixon ER, Lui LM, Nielsen TN, Bowman S, von Netzer F, Moon JW, Schadt CW, Rodriguez M, Lowe K, Joyner D, Davis KJ, Wu X, Chakraborty R, Fields MW, Zhou J, Hazen TC, Arkin AP, Wankel SD, Baliga NS, Stahl DA. Contribution of Microorganisms with the Clade II Nitrous Oxide Reductase to Suppression of Surface Emissions of Nitrous Oxide. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:7056-7065. [PMID: 38608141 DOI: 10.1021/acs.est.3c07972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2024]
Abstract
The sources and sinks of nitrous oxide, as control emissions to the atmosphere, are generally poorly constrained for most environmental systems. Initial depth-resolved analysis of nitrous oxide flux from observation wells and the proximal surface within a nitrate contaminated aquifer system revealed high subsurface production but little escape from the surface. To better understand the environmental controls of production and emission at this site, we used a combination of isotopic, geochemical, and molecular analyses to show that chemodenitrification and bacterial denitrification are major sources of nitrous oxide in this subsurface, where low DO, low pH, and high nitrate are correlated with significant nitrous oxide production. Depth-resolved metagenomes showed that consumption of nitrous oxide near the surface was correlated with an enrichment of Clade II nitrous oxide reducers, consistent with a growing appreciation of their importance in controlling release of nitrous oxide to the atmosphere. Our work also provides evidence for the reduction of nitrous oxide at a pH of 4, well below the generally accepted limit of pH 5.
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Affiliation(s)
- Kristopher A Hunt
- Department of Civil and Environmental Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Alex V Carr
- Department of Molecular Engineering Sciences, University of Washington, Seattle, Washington 98105, United States
- Institute for Systems Biology, Seattle, Washington 98109, United States
| | - Anne E Otwell
- Department of Civil and Environmental Engineering, University of Washington, Seattle, Washington 98195, United States
| | | | - Kathleen S Walker
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Emma R Dixon
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Lauren M Lui
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Torben N Nielsen
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Samuel Bowman
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02540, United States
| | - Frederick von Netzer
- Department of Civil and Environmental Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Ji-Won Moon
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Christopher W Schadt
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Miguel Rodriguez
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Kenneth Lowe
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Dominique Joyner
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Katherine J Davis
- Center for Biofilm Engineering, Montana State University, Bozeman, Montana 59717, United States
| | - Xiaoqin Wu
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Romy Chakraborty
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Matthew W Fields
- Center for Biofilm Engineering, Montana State University, Bozeman, Montana 59717, United States
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, Montana 59717, United States
| | - Jizhong Zhou
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Institute for Environmental Genomics and Department of Botany and Microbiology, University of Oklahoma, Norman, Oklahoma 73019, United States
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Terry C Hazen
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Adam P Arkin
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Bioengineering, University of California Berkeley, Berkeley, California 94720, United States
| | - Scott D Wankel
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02540, United States
| | - Nitin S Baliga
- Department of Molecular Engineering Sciences, University of Washington, Seattle, Washington 98105, United States
- Institute for Systems Biology, Seattle, Washington 98109, United States
| | - David A Stahl
- Department of Civil and Environmental Engineering, University of Washington, Seattle, Washington 98195, United States
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Zhang IH, Borer B, Zhao R, Wilbert S, Newman DK, Babbin AR. Uncultivated DPANN archaea are ubiquitous inhabitants of global oxygen-deficient zones with diverse metabolic potential. mBio 2024; 15:e0291823. [PMID: 38380943 PMCID: PMC10936187 DOI: 10.1128/mbio.02918-23] [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: 10/26/2023] [Accepted: 01/22/2024] [Indexed: 02/22/2024] Open
Abstract
Archaea belonging to the DPANN (Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota, and Nanohaloarchaeota) superphylum have been found in an expanding number of environments and perform a variety of biogeochemical roles, including contributing to carbon, sulfur, and nitrogen cycling. Generally characterized by ultrasmall cell sizes and reduced genomes, DPANN archaea may form mutualistic, commensal, or parasitic interactions with various archaeal and bacterial hosts, influencing the ecology and functioning of microbial communities. While DPANN archaea reportedly comprise a sizeable fraction of the archaeal community within marine oxygen-deficient zone (ODZ) water columns, little is known about their metabolic capabilities in these ecosystems. We report 33 novel metagenome-assembled genomes (MAGs) belonging to the DPANN phyla Nanoarchaeota, Pacearchaeota, Woesearchaeota, Undinarchaeota, Iainarchaeota, and SpSt-1190 from pelagic ODZs in the Eastern Tropical North Pacific and the Arabian Sea. We find these archaea to be permanent, stable residents of all three major ODZs only within anoxic depths, comprising up to 1% of the total microbial community and up to 25%-50% of archaea as estimated from read mapping to MAGs. ODZ DPANN appear to be capable of diverse metabolic functions, including fermentation, organic carbon scavenging, and the cycling of sulfur, hydrogen, and methane. Within a majority of ODZ DPANN, we identify a gene homologous to nitrous oxide reductase. Modeling analyses indicate the feasibility of a nitrous oxide reduction metabolism for host-attached symbionts, and the small genome sizes and reduced metabolic capabilities of most DPANN MAGs suggest host-associated lifestyles within ODZs. IMPORTANCE Archaea from the DPANN (Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota, and Nanohaloarchaeota) superphylum have diverse metabolic capabilities and participate in multiple biogeochemical cycles. While metagenomics and enrichments have revealed that many DPANN are characterized by ultrasmall genomes, few biosynthetic genes, and episymbiotic lifestyles, much remains unknown about their biology. We report 33 new DPANN metagenome-assembled genomes originating from the three global marine oxygen-deficient zones (ODZs), the first from these regions. We survey DPANN abundance and distribution within the ODZ water column, investigate their biosynthetic capabilities, and report potential roles in the cycling of organic carbon, methane, and nitrogen. We test the hypothesis that nitrous oxide reductases found within several ODZ DPANN genomes may enable ultrasmall episymbionts to serve as nitrous oxide consumers when attached to a host nitrous oxide producer. Our results indicate DPANN archaea as ubiquitous residents within the anoxic core of ODZs with the potential to produce or consume key compounds.
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Affiliation(s)
- Irene H. Zhang
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Benedict Borer
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Rui Zhao
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Steven Wilbert
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Dianne K. Newman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA
| | - Andrew R. Babbin
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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5
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Cram JA, Hollins A, McCarty AJ, Martinez G, Cui M, Gomes ML, Fuchsman CA. Microbial diversity and abundance vary along salinity, oxygen, and particle size gradients in the Chesapeake Bay. Environ Microbiol 2024; 26:e16557. [PMID: 38173306 DOI: 10.1111/1462-2920.16557] [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: 01/25/2023] [Accepted: 11/27/2023] [Indexed: 01/05/2024]
Abstract
Marine snow and other particles are abundant in estuaries, where they drive biogeochemical transformations and elemental transport. Particles range in size, thereby providing a corresponding gradient of habitats for marine microorganisms. We used standard normalized amplicon sequencing, verified with microscopy, to characterize taxon-specific microbial abundances, (cells per litre of water and per milligrams of particles), across six particle size classes, ranging from 0.2 to 500 μm, along the main stem of the Chesapeake Bay estuary. Microbial communities varied in salinity, oxygen concentrations, and particle size. Many taxonomic groups were most densely packed on large particles (in cells/mg particles), yet were primarily associated with the smallest particle size class, because small particles made up a substantially larger portion of total particle mass. However, organisms potentially involved in methanotrophy, nitrite oxidation, and sulphate reduction were found primarily on intermediately sized (5-180 μm) particles, where species richness was also highest. All abundant ostensibly free-living organisms, including SAR11 and Synecococcus, appeared on particles, albeit at lower abundance than in the free-living fraction, suggesting that aggregation processes may incorporate them into particles. Our approach opens the door to a more quantitative understanding of the microscale and macroscale biogeography of marine microorganisms.
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Affiliation(s)
- Jacob A Cram
- Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, Maryland, USA
| | - Ashley Hollins
- Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, Maryland, USA
| | - Alexandra J McCarty
- Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, Maryland, USA
- Marine Advisory Program, Virginia Institute of Marine Science, Gloucester, Virginia, USA
| | | | - Minming Cui
- Earth and Planetary Sciences, Johns Hopkins University, Baltimore, Maryland, USA
| | - Maya L Gomes
- Earth and Planetary Sciences, Johns Hopkins University, Baltimore, Maryland, USA
| | - Clara A Fuchsman
- Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, Maryland, USA
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6
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Wang X, Xiang B, Li J, Zhang M, Frostegard A, Bakken L, Zhang X. Using adaptive and aggressive N 2O-reducing bacteria to augment digestate fertilizer for mitigating N 2O emissions from agricultural soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166284. [PMID: 37586512 DOI: 10.1016/j.scitotenv.2023.166284] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 08/09/2023] [Accepted: 08/11/2023] [Indexed: 08/18/2023]
Abstract
Nitrous oxide (N2O) emitted from agricultural soils destroys stratospheric ozone and contributes to global warming. A promising approach to reduce emissions is fertilizing the soil using organic wastes augmented by non-denitrifying N2O-reducing bacteria (NNRB). To realize this potential, we need a suite of NNRB strains that fulfill several criteria: efficient reduction of N2O, ability to grow in organic waste, and ability to survive in farmland soil. In this study, we enriched such organisms by sequential anaerobic batch incubations with N2O and reciprocating inoculation between the sterilized substrates of anaerobic manure digestate and soils. 16S rDNA amplicon sequencing and metagenomics analysis showed that a cluster of bacteria containing nosZ genes encoding N2O-reductase, was enriched during the incubation process. Strains of several dominant members were then isolated and characterized, and three of them were found to harbor the nosZ gene but none of the other denitrifying genes, thus qualifying as NNRB. The selected isolates were tested for their capacities to reduce N2O emissions from three different typical Chinese farmland soils. The results indicated the significant mitigation effect of these isolates, even in very acidic red soil. In conclusion, this study demonstrated a strategy to engineer the soil microbiome with promising NNRB with high adaptability to livestock manure digestate as well as different agricultural soils, which would be suitable for developing novel fertilizer for farmland application to efficiently mitigate the N2O emissions from agricultural soils.
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Affiliation(s)
- Xinhui Wang
- State Key Laboratory of Microbial Metabolism, and Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Baoyu Xiang
- State Key Laboratory of Microbial Metabolism, and Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ji Li
- State Key Laboratory of Microbial Metabolism, and Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Menghui Zhang
- State Key Laboratory of Microbial Metabolism, and Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Asa Frostegard
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Aas, Norway
| | - Lars Bakken
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Aas, Norway
| | - Xiaojun Zhang
- State Key Laboratory of Microbial Metabolism, and Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
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7
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Yoon S, Heo H, Han H, Song DU, Bakken LR, Frostegård Å, Yoon S. Suggested role of NosZ in preventing N 2O inhibition of dissimilatory nitrite reduction to ammonium. mBio 2023; 14:e0154023. [PMID: 37737639 PMCID: PMC10653820 DOI: 10.1128/mbio.01540-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 07/31/2023] [Indexed: 09/23/2023] Open
Abstract
IMPORTANCE Dissimilatory nitrate/nitrite reduction to ammonium (DNRA) is a microbial energy-conserving process that reduces NO3 - and/or NO2 - to NH4 +. Interestingly, DNRA-catalyzing microorganisms possessing nrfA genes are occasionally found harboring nosZ genes encoding nitrous oxide reductases, i.e., the only group of enzymes capable of removing the potent greenhouse gas N2O. Here, through a series of physiological experiments examining DNRA metabolism in one of such microorganisms, Bacillus sp. DNRA2, we have discovered that N2O may delay the transition to DNRA upon an oxic-to-anoxic transition, unless timely removed by the nitrous oxide reductases. These observations suggest a novel explanation as to why some nrfA-possessing microorganisms have retained nosZ genes: to remove N2O that may otherwise interfere with the transition from O2 respiration to DNRA.
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Affiliation(s)
- Sojung Yoon
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Hokwan Heo
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Heejoo Han
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Dong-Uk Song
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Lars R. Bakken
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Åsa Frostegård
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Sukhwan Yoon
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
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8
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Zhang IH, Borer B, Zhao R, Wilbert S, Newman DK, Babbin AR. Uncultivated DPANN archaea are ubiquitous inhabitants of global oxygen deficient zones with diverse metabolic potential. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.30.564641. [PMID: 37961710 PMCID: PMC10634959 DOI: 10.1101/2023.10.30.564641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Archaea belonging to the DPANN superphylum have been found within an expanding number of environments and perform a variety of biogeochemical roles, including contributing to carbon, sulfur, and nitrogen cycling. Generally characterized by ultrasmall cell sizes and reduced genomes, DPANN archaea may form mutualistic, commensal, or parasitic interactions with various archaeal and bacterial hosts, influencing the ecology and functioning of microbial communities. While DPANN archaea reportedly comprise 15-26% of the archaeal community within marine oxygen deficient zone (ODZ) water columns, little is known about their metabolic capabilities in these ecosystems. We report 33 novel metagenome-assembled genomes belonging to DPANN phyla Nanoarchaeota, Pacearchaeota, Woesarchaeota, Undinarchaeota, Iainarchaeota, and SpSt-1190 from pelagic ODZs in the Eastern Tropical North Pacific and Arabian Sea. We find these archaea to be permanent, stable residents of all 3 major ODZs only within anoxic depths, comprising up to 1% of the total microbial community and up to 25-50% of archaea. ODZ DPANN appear capable of diverse metabolic functions, including fermentation, organic carbon scavenging, and the cycling of sulfur, hydrogen, and methane. Within a majority of ODZ DPANN, we identify a gene homologous to nitrous oxide reductase. Modeling analyses indicate the feasibility of a nitrous oxide reduction metabolism for host-attached symbionts, and the small genome sizes and reduced metabolic capabilities of most DPANN MAGs suggest host-associated lifestyles within ODZs.
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Affiliation(s)
- Irene H. Zhang
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Benedict Borer
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Rui Zhao
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Steven Wilbert
- Divisions of Biology and Biological Engineering and Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA
| | - Dianne K. Newman
- Divisions of Biology and Biological Engineering and Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA
| | - Andrew R. Babbin
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
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9
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Hu Y, Wu J, Ye J, Liu X, Wang Y, Ye F, Hong Y. The imbalance between N 2O production and reduction by multi-microbial communities determines sedimentary N 2O emission potential in the Pearl River Estuary. MARINE ENVIRONMENTAL RESEARCH 2023; 190:106119. [PMID: 37535997 DOI: 10.1016/j.marenvres.2023.106119] [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: 05/22/2023] [Revised: 07/04/2023] [Accepted: 07/26/2023] [Indexed: 08/05/2023]
Abstract
Denitrification is the dominant process of nitrogen removal and nitrous oxide (N2O) emissions in estuarine ecosystems. However, little is known regarding the microbial mechanism of the production and reduction of N2O in estuaries. We investigated in situ dissolved N2O as well as potential N2O production rate (NPR), reduction rate (NRR), and emission rate (NER), and key functional genes related to N2O transformation of denitrification in the Pearl River Estuary. Higher N2O emission potential was found in the upstream and midstream regions with higher NPR and lower NRR values. In contrast, higher NRR values were detected in downstream. Notably, nirS and nirK type N2O producers dominated the upstream zone, whereas abundant N2O reducers, especially nosZ II type N2O reducers, were observed in downstream. Most importantly, the gene abundance ratio (Rnir/nosZ) was significantly correlated with the N2O emission potential (Re). Niche differentiation between N2O producers and N2O reducers from upstream to downstream affected N2O emission potential. This study highlights the N2O emission potential in estuarine sediments is determined by an imbalance between N2O production and the reduction of multi-bacterial communities.
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Affiliation(s)
- Yaohao Hu
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, PR China; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China
| | - Jiapeng Wu
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, PR China
| | - Jiaqi Ye
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, PR China
| | - Xiaohan Liu
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, PR China
| | - Yu Wang
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, PR China
| | - Fei Ye
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, PR China
| | - Yiguo Hong
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, PR China.
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10
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Zhang IH, Sun X, Jayakumar A, Fortin SG, Ward BB, Babbin AR. Partitioning of the denitrification pathway and other nitrite metabolisms within global oxygen deficient zones. ISME COMMUNICATIONS 2023; 3:76. [PMID: 37474642 PMCID: PMC10359470 DOI: 10.1038/s43705-023-00284-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/05/2023] [Accepted: 07/11/2023] [Indexed: 07/22/2023]
Abstract
Oxygen deficient zones (ODZs) account for about 30% of total oceanic fixed nitrogen loss via processes including denitrification, a microbially mediated pathway proceeding stepwise from NO3- to N2. This process may be performed entirely by complete denitrifiers capable of all four enzymatic steps, but many organisms possess only partial denitrification pathways, either producing or consuming key intermediates such as the greenhouse gas N2O. Metagenomics and marker gene surveys have revealed a diversity of denitrification genes within ODZs, but whether these genes co-occur within complete or partial denitrifiers and the identities of denitrifying taxa remain open questions. We assemble genomes from metagenomes spanning the ETNP and Arabian Sea, and map these metagenome-assembled genomes (MAGs) to 56 metagenomes from all three major ODZs to reveal the predominance of partial denitrifiers, particularly single-step denitrifiers. We find niche differentiation among nitrogen-cycling organisms, with communities performing each nitrogen transformation distinct in taxonomic identity and motility traits. Our collection of 962 MAGs presents the largest collection of pelagic ODZ microorganisms and reveals a clearer picture of the nitrogen cycling community within this environment.
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Affiliation(s)
- Irene H Zhang
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Program in Microbiology, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Xin Sun
- Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, USA
- Department of Geosciences, Princeton University, Princeton, NJ, USA
| | - Amal Jayakumar
- Department of Geosciences, Princeton University, Princeton, NJ, USA
| | | | - Bess B Ward
- Department of Geosciences, Princeton University, Princeton, NJ, USA
| | - Andrew R Babbin
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
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11
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Xiang H, Hong Y, Wu J, Wang Y, Ye F, Hu Z, Qu Z, Long A. NosZ-II-type N 2O-reducing bacteria play dominant roles in determining the release potential of N 2O from sediments in the Pearl River Estuary, China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 329:121732. [PMID: 37116571 DOI: 10.1016/j.envpol.2023.121732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 04/09/2023] [Accepted: 04/26/2023] [Indexed: 05/04/2023]
Abstract
The microbial reduction of N2O serves as a "gatekeeper" for N2O emissions, determining the flux of N2O release into the atmosphere. Estuaries are active regions for N2O emissions, but the microbial functions of N2O-reducing bacteria in estuarine ecosystems are not well understood. In this study, the 15N isotope tracer method, qPCR, and high-throughput sequencing were used to analyze N2O production, reduction, and emission processes in surface sediments of the Pearl River Estuary. The 15N isotope tracer experiment showed that the N2O production rates declined and the N2O reduction potential (Rr, the ratio of N2O reduction rates to N2O production rates) increased from upstream to downstream of the Pearl River Estuary, leading to a corresponding decrease of the N2O emission rates from upstream to downstream. The gene abundance ratio of nosZ/nir gradually increased from upstream to downstream and was negatively correlated with the water N2O saturation. The gene abundance of nosZ II was significantly higher than that of nosZ I in the estuary, and the nosZ II/nosZ I abundance ratio was positively correlated with N2O reduction potential. Furthermore, the community composition of NosZ-I- and NosZ-II-type N2O-reducing bacteria shifted from upstream to downstream. NosZ-II-type N2O-reducing bacteria, especially Myxococcales, Thiotrichales, and Gemmatimonadetes species, contributed to the high N2O reduction potential in the downstream. Our results suggest that NosZ-II-type N2O-reducing bacteria play a dominant role in determining the release potential of N2O from sediments in the Pearl River Estuary. This study provides a new insight into the function of microbial N2O reduction in estuarine ecosystems.
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Affiliation(s)
- Hua Xiang
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 10006, PR China; State Key Laboratory of Tropical Oceanography (LTO), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Yiguo Hong
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 10006, PR China.
| | - Jiapeng Wu
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 10006, PR China
| | - Yu Wang
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 10006, PR China
| | - Fei Ye
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 10006, PR China
| | - Zheng Hu
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 10006, PR China
| | - Zhiming Qu
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 10006, PR China
| | - Aimin Long
- State Key Laboratory of Tropical Oceanography (LTO), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
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12
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Jameson BD, Murdock SA, Ji Q, Stevens CJ, Grundle DS, Kim Juniper S. Network analysis of 16S rRNA sequences suggests microbial keystone taxa contribute to marine N 2O cycling. Commun Biol 2023; 6:212. [PMID: 36823449 PMCID: PMC9950131 DOI: 10.1038/s42003-023-04597-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 02/15/2023] [Indexed: 02/25/2023] Open
Abstract
The mechanisms by which large-scale microbial community function emerges from complex ecological interactions between individual taxa and functional groups remain obscure. We leveraged network analyses of 16S rRNA amplicon sequences obtained over a seven-month timeseries in seasonally anoxic Saanich Inlet (Vancouver Island, Canada) to investigate relationships between microbial community structure and water column N2O cycling. Taxa separately broadly into three discrete subnetworks with contrasting environmental distributions. Oxycline subnetworks were structured around keystone aerobic heterotrophs that correlated with nitrification rates and N2O supersaturations, linking N2O production and accumulation to taxa involved in organic matter remineralization. Keystone taxa implicated in anaerobic carbon, nitrogen, and sulfur cycling in anoxic environments clustered together in a low-oxygen subnetwork that correlated positively with nitrification N2O yields and N2O production from denitrification. Close coupling between N2O producers and consumers in the anoxic basin is indicated by strong correlations between the low-oxygen subnetwork, PICRUSt2-predicted nitrous oxide reductase (nosZ) gene abundances, and N2O undersaturation. This study implicates keystone taxa affiliated with common ODZ groups as a potential control on water column N2O cycling and provides a theoretical basis for further investigations into marine microbial interaction networks.
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Affiliation(s)
- Brett D Jameson
- School of Earth & Ocean Sciences, University of Victoria, P.O. Box 1700 Station CSC, Victoria, BC, V8W 2Y2, Canada.
| | - Sheryl A Murdock
- Department of Biology, University of Victoria, P.O. Box 1700 CSC, Victoria, BC, V8W 2Y2, Canada
- Bermuda Institute of Ocean Sciences, 17 Biological Station, St. George's, GE01, Bermuda
| | - Qixing Ji
- Bermuda Institute of Ocean Sciences, 17 Biological Station, St. George's, GE01, Bermuda
- Thrust of Earth, Ocean & Atmospheric Sciences, Hong Kong University of Science and Technology (Guangzhou), Nansha, Guangzhou, Guangdong, 511400, China
| | - Catherine J Stevens
- School of Earth & Ocean Sciences, University of Victoria, P.O. Box 1700 Station CSC, Victoria, BC, V8W 2Y2, Canada
| | - Damian S Grundle
- Bermuda Institute of Ocean Sciences, 17 Biological Station, St. George's, GE01, Bermuda
- School of Ocean Futures & School of Earth & Space Exploration, Arizona State University, Tempe, AZ, 85287-7904, USA
| | - S Kim Juniper
- School of Earth & Ocean Sciences, University of Victoria, P.O. Box 1700 Station CSC, Victoria, BC, V8W 2Y2, Canada
- Department of Biology, University of Victoria, P.O. Box 1700 CSC, Victoria, BC, V8W 2Y2, Canada
- Ocean Networks Canada, 2474 Arbutus Road, Victoria, BC, V8N 1V8, Canada
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13
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Vuillemin A. Nitrogen cycling activities during decreased stratification in the coastal oxygen minimum zone off Namibia. Front Microbiol 2023; 14:1101902. [PMID: 36846760 PMCID: PMC9950273 DOI: 10.3389/fmicb.2023.1101902] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 01/20/2023] [Indexed: 02/12/2023] Open
Abstract
Productive oxygen minimum zones are regions dominated by heterotrophic denitrification fueled by sinking organic matter. Microbial redox-sensitive transformations therein result in the loss and overall geochemical deficit in inorganic fixed nitrogen in the water column, thereby impacting global climate in terms of nutrient equilibrium and greenhouse gases. Here, geochemical data are combined with metagenomes, metatranscriptomes, and stable-isotope probing incubations from the water column and subseafloor of the Benguela upwelling system. The taxonomic composition of 16S rRNA genes and relative expression of functional marker genes are used to explore metabolic activities by nitrifiers and denitrifiers under decreased stratification and increased lateral ventilation in Namibian coastal waters. Active planktonic nitrifiers were affiliated with Candidatus Nitrosopumilus and Candidatus Nitrosopelagicus among Archaea, and Nitrospina, Nitrosomonas, Nitrosococcus, and Nitrospira among Bacteria. Concurrent evidence from taxonomic and functional marker genes shows that populations of Nitrososphaeria and Nitrospinota were highly active under dysoxic conditions, coupling ammonia and nitrite oxidation with respiratory nitrite reduction, but minor metabolic activity toward mixotrophic use of simple nitrogen compounds. Although active reduction of nitric oxide to nitrous oxide by Nitrospirota, Gammaproteobacteria, and Desulfobacterota was tractable in bottom waters, the produced nitrous oxide was apparently scavenged at the ocean surface by Bacteroidota. Planctomycetota involved in anaerobic ammonia oxidation were identified in dysoxic waters and their underlying sediments, but were not found to be metabolically active due to limited availability of nitrite. Consistent with water column geochemical profiles, metatranscriptomic data demonstrate that nitrifier denitrification is fueled by fixed and organic nitrogen dissolved in dysoxic waters, and prevails over canonical denitrification and anaerobic oxidation of ammonia when the Namibian coastal waters and sediment-water interface on the shelf are ventilated by lateral currents during austral winter.
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14
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Cevallos MA, Degli Esposti M. New Alphaproteobacteria Thrive in the Depths of the Ocean with Oxygen Gradient. Microorganisms 2022; 10:microorganisms10020455. [PMID: 35208909 PMCID: PMC8879329 DOI: 10.3390/microorganisms10020455] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 02/10/2022] [Accepted: 02/15/2022] [Indexed: 02/04/2023] Open
Abstract
We survey here the Alphaproteobacteria, a large class encompassing physiologically diverse bacteria which are divided in several orders established since 2007. Currently, there is considerable uncertainty regarding the classification of an increasing number of marine metagenome-assembled genomes (MAGs) that remain poorly defined in their taxonomic position within Alphaproteobacteria. The traditional classification of NCBI taxonomy is increasingly complemented by the Genome Taxonomy Database (GTDB), but the two taxonomies differ considerably in the classification of several Alphaproteobacteria, especially from ocean metagenomes. We analyzed the classification of Alphaproteobacteria lineages that are most common in marine environments, using integrated approaches of phylogenomics and functional profiling of metabolic features that define their aerobic metabolism. Using protein markers such as NuoL, the largest membrane subunit of complex I, we have identified new clades of Alphaproteobacteria that are specific to marine niches with steep oxygen gradients (oxycline). These bacteria have relatives among MAGs found in anoxic strata of Lake Tanganyika and together define a lineage that is distinct from either Rhodospirillales or Sneathiellales. We characterized in particular the new ‘oxycline’ clade. Our analysis of Alphaproteobacteria also reveals new clues regarding the ancestry of mitochondria, which likely evolved in oxycline marine environments.
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15
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Large-scale protein level comparison of Deltaproteobacteria reveals cohesive metabolic groups. THE ISME JOURNAL 2022; 16:307-320. [PMID: 34331018 PMCID: PMC8692467 DOI: 10.1038/s41396-021-01057-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 06/30/2021] [Accepted: 07/05/2021] [Indexed: 02/07/2023]
Abstract
Deltaproteobacteria, now proposed to be the phyla Desulfobacterota, Myxococcota, and SAR324, are ubiquitous in marine environments and play essential roles in global carbon, sulfur, and nutrient cycling. Despite their importance, our understanding of these bacteria is biased towards cultured organisms. Here we address this gap by compiling a genomic catalog of 1 792 genomes, including 402 newly reconstructed and characterized metagenome-assembled genomes (MAGs) from coastal and deep-sea sediments. Phylogenomic analyses reveal that many of these novel MAGs are uncultured representatives of Myxococcota and Desulfobacterota that are understudied. To better characterize Deltaproteobacteria diversity, metabolism, and ecology, we clustered ~1 500 genomes based on the presence/absence patterns of their protein families. Protein content analysis coupled with large-scale metabolic reconstructions separates eight genomic clusters of Deltaproteobacteria with unique metabolic profiles. While these eight clusters largely correspond to phylogeny, there are exceptions where more distantly related organisms appear to have similar ecological roles and closely related organisms have distinct protein content. Our analyses have identified previously unrecognized roles in the cycling of methylamines and denitrification among uncultured Deltaproteobacteria. This new view of Deltaproteobacteria diversity expands our understanding of these dominant bacteria and highlights metabolic abilities across diverse taxa.
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16
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Guo H, Han S, Lee DJ. Genomic studies on natural and engineered aquatic denitrifying eco-systems: A research update. BIORESOURCE TECHNOLOGY 2021; 326:124740. [PMID: 33497924 DOI: 10.1016/j.biortech.2021.124740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 01/12/2021] [Accepted: 01/14/2021] [Indexed: 06/12/2023]
Abstract
Excess nitrogenous compounds in municipal or industrial wastewaters can stimulate growth of denitrifying bacteria, in return, to convert potentially hazardous nitrate to inorganic nitrogen gas. To explore the community structure, distributions and succession of functional strains, and their interactions with other microbial communities, contemporary studies were performed based on detailed genomic analysis. This mini-review updated contemporary genomic studies on denitrifying genes in natural and engineered aquatic systems, with the constructed wetlands being the demonstrative system for the latter. Prospects for the employment of genomic studies on denitrifying systems for process design, optimization and development of novel denitrifying processes were discussed.
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Affiliation(s)
- Hongliang Guo
- College of Forestry, Northeast Forestry University, Harbin 150040, China
| | - Song Han
- College of Forestry, Northeast Forestry University, Harbin 150040, China
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan; College of Technology and Engineering, National Taiwan Normal University, Taipei 10610, Taiwan; College of Engineering, Tunghai University, Taichung 40070, Taiwan.
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