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Awala SI, Gwak JH, Kim Y, Jung MY, Dunfield PF, Wagner M, Rhee SK. Nitrous oxide respiration in acidophilic methanotrophs. Nat Commun 2024; 15:4226. [PMID: 38762502 PMCID: PMC11102522 DOI: 10.1038/s41467-024-48161-z] [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: 01/03/2024] [Accepted: 04/22/2024] [Indexed: 05/20/2024] Open
Abstract
Aerobic methanotrophic bacteria are considered strict aerobes but are often highly abundant in hypoxic and even anoxic environments. Despite possessing denitrification genes, it remains to be verified whether denitrification contributes to their growth. Here, we show that acidophilic methanotrophs can respire nitrous oxide (N2O) and grow anaerobically on diverse non-methane substrates, including methanol, C-C substrates, and hydrogen. We study two strains that possess N2O reductase genes: Methylocella tundrae T4 and Methylacidiphilum caldifontis IT6. We show that N2O respiration supports growth of Methylacidiphilum caldifontis at an extremely acidic pH of 2.0, exceeding the known physiological pH limits for microbial N2O consumption. Methylocella tundrae simultaneously consumes N2O and CH4 in suboxic conditions, indicating robustness of its N2O reductase activity in the presence of O2. Furthermore, in O2-limiting conditions, the amount of CH4 oxidized per O2 reduced increases when N2O is added, indicating that Methylocella tundrae can direct more O2 towards methane monooxygenase. Thus, our results demonstrate that some methanotrophs can respire N2O independently or simultaneously with O2, which may facilitate their growth and survival in dynamic environments. Such metabolic capability enables these bacteria to simultaneously reduce the release of the key greenhouse gases CO2, CH4, and N2O.
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Affiliation(s)
- Samuel Imisi Awala
- Department of Biological Sciences and Biotechnology, Chungbuk National University, 1 Chungdae-ro, Seowon-Gu, Cheongju, 28644, Republic of Korea
- Center for Ecology and Environmental Toxicology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju, 28644, South Korea
| | - Joo-Han Gwak
- Department of Biological Sciences and Biotechnology, Chungbuk National University, 1 Chungdae-ro, Seowon-Gu, Cheongju, 28644, Republic of Korea
| | - Yongman Kim
- Department of Biological Sciences and Biotechnology, Chungbuk National University, 1 Chungdae-ro, Seowon-Gu, Cheongju, 28644, Republic of Korea
| | - Man-Young Jung
- Interdisciplinary Graduate Programme in Advance Convergence Technology and Science, Jeju National University, Jeju, Republic of Korea
- Department of Science Education, Jeju National University, Jeju, Republic of Korea
- Jeju Microbiome Center, Jeju National University, Jeju, Republic of Korea
| | - Peter F Dunfield
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, AB, T2N 1N4, Canada
| | - Michael Wagner
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Althanstrasse 14, A-1090, Vienna, Austria
- Department of Chemistry and Bioscience, Center for Microbial Communities, Aalborg University, Fredrik Bajers Vej 7H, 9220, Aalborg, Denmark
| | - Sung-Keun Rhee
- Department of Biological Sciences and Biotechnology, Chungbuk National University, 1 Chungdae-ro, Seowon-Gu, Cheongju, 28644, Republic of Korea.
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2
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Gios E, Verbruggen E, Audet J, Burns R, Butterbach-Bahl K, Espenberg M, Fritz C, Glatzel S, Jurasinski G, Larmola T, Mander Ü, Nielsen C, Rodriguez AF, Scheer C, Zak D, Silvennoinen HM. Unraveling microbial processes involved in carbon and nitrogen cycling and greenhouse gas emissions in rewetted peatlands by molecular biology. BIOGEOCHEMISTRY 2024; 167:609-629. [PMID: 38707517 PMCID: PMC11068585 DOI: 10.1007/s10533-024-01122-6] [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: 05/31/2023] [Accepted: 01/22/2024] [Indexed: 05/07/2024]
Abstract
Restoration of drained peatlands through rewetting has recently emerged as a prevailing strategy to mitigate excessive greenhouse gas emissions and re-establish the vital carbon sequestration capacity of peatlands. Rewetting can help to restore vegetation communities and biodiversity, while still allowing for extensive agricultural management such as paludiculture. Belowground processes governing carbon fluxes and greenhouse gas dynamics are mediated by a complex network of microbial communities and processes. Our understanding of this complexity and its multi-factorial controls in rewetted peatlands is limited. Here, we summarize the research regarding the role of soil microbial communities and functions in driving carbon and nutrient cycling in rewetted peatlands including the use of molecular biology techniques in understanding biogeochemical processes linked to greenhouse gas fluxes. We emphasize that rapidly advancing molecular biology approaches, such as high-throughput sequencing, are powerful tools helping to elucidate the dynamics of key biogeochemical processes when combined with isotope tracing and greenhouse gas measuring techniques. Insights gained from the gathered studies can help inform efficient monitoring practices for rewetted peatlands and the development of climate-smart restoration and management strategies. Supplementary Information The online version contains supplementary material available at 10.1007/s10533-024-01122-6.
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Affiliation(s)
- Emilie Gios
- NINA, Norwegian Institute for Nature Research, PO Box 5685, Torgarden, NO-7485 Trondheim, Norway
| | - Erik Verbruggen
- Plants and Ecosystems Research Group, Department of Biology, University of Antwerp, Universiteitsplein 1, Wilrijk, 2610 Antwerp, Belgium
| | - Joachim Audet
- Department of Ecoscience, Aarhus University, C.F. Møllers Allé, 8000 Aarhus, Denmark
| | - Rachel Burns
- Department of Geosciences and Natural Resource Management, University of Copenhagen, 1350 Copenhagen, Denmark
| | - Klaus Butterbach-Bahl
- Institute of Meteorology and Climate Research, Atmospheric Environmental Research, Karlsruhe Institute of Technology, 82467 Garmisch-Partenkirchen, Germany
- Department of Agroecology, Pioneer Center for Research in Sustainable Agricultural Futures (Land-CRAFT), Aarhus University, 8000 Aarhus, Denmark
| | - Mikk Espenberg
- Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, 46 St., Vanemuise, 51003 Tartu, Estonia
| | - Christian Fritz
- Aquatic Ecology and Environmental Biology, Radboud Institute for Biological and Environmental Sciences (RIBES), Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Stephan Glatzel
- Department of Geography and Regional Research, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
| | - Gerald Jurasinski
- Faculty of Agriculture and Environment, Landscape Ecology and Site Evaluation, University of Rostock, Justus-von-Liebig-Weg 6, 18059 Rostock, Germany
- Department of Maritime Systems, Faculty of Interdisciplinary Research, University of Rostock, Albert- Einstein-Straße 3, 18059 Rostock, Germany
| | - Tuula Larmola
- Natural Resources Institute Finland (Luke), 00790 Helsinki, Finland
| | - Ülo Mander
- Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, 46 St., Vanemuise, 51003 Tartu, Estonia
| | - Claudia Nielsen
- Department of Agroecology, Faculty of Technical Sciences, Aarhus University, Blichers Alle 20, 8830 Tjele, Denmark
- CBIO, Centre for Circular Bioeconomy, Aarhus University, 8830 Tjele, Denmark
| | - Andres F. Rodriguez
- Department of Agroecology, Faculty of Technical Sciences, Aarhus University, Blichers Alle 20, 8830 Tjele, Denmark
| | - Clemens Scheer
- Institute of Meteorology and Climate Research, Atmospheric Environmental Research, Karlsruhe Institute of Technology, 82467 Garmisch-Partenkirchen, Germany
| | - Dominik Zak
- Department of Ecoscience, Aarhus University, C.F. Møllers Allé, 8000 Aarhus, Denmark
- Department of Ecohydrology and Biogeochemistry, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 301, 12587 Berlin, Germany
| | - Hanna M. Silvennoinen
- NINA, Norwegian Institute for Nature Research, PO Box 5685, Torgarden, NO-7485 Trondheim, Norway
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Meier AB, Oppermann S, Drake HL, Schmidt O. The root zone of graminoids: A niche for H2-consuming acetogens in a minerotrophic peatland. Front Microbiol 2022; 13:978296. [PMID: 35992704 PMCID: PMC9391049 DOI: 10.3389/fmicb.2022.978296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
The importance of acetogens for H2 turnover and overall anaerobic degradation in peatlands remains elusive. In the well-studied minerotrophic peatland fen Schlöppnerbrunnen, H2-consuming acetogens are conceptualized to be largely outcompeted by iron reducers, sulfate reducers, and hydrogenotrophic methanogens in bulk peat soil. However, in root zones of graminoids, fermenters thriving on rhizodeposits and root litter might temporarily provide sufficient H2 for acetogens. In the present study, root-free peat soils from around the roots of Molinia caerulea and Carex rostrata (i.e., two graminoids common in fen Schlöpnnerbrunnen) were anoxically incubated with or without supplemental H2 to simulate conditions of high and low H2 availability in the fen. In unsupplemented soil treatments, H2 concentrations were largely below the detection limit (∼10 ppmV) and possibly too low for acetogens and methanogens, an assumption supported by the finding that neither acetate nor methane substantially accumulated. In the presence of supplemental H2, acetate accumulation exceeded CH4 accumulation in Molinia soil whereas acetate and methane accumulated equally in Carex soil. However, reductant recoveries indicated that initially, additional unknown processes were involved either in H2 consumption or the consumption of acetate produced by H2-consuming acetogens. 16S rRNA and 16S rRNA gene analyses revealed that potential acetogens (Clostridium, Holophagaceae), methanogens (Methanocellales, Methanobacterium), iron reducers (Geobacter), and physiologically uncharacterized phylotypes (Acidobacteria, Actinobacteria, Bacteroidetes) were stimulated by supplemental H2 in soil treatments. Phylotypes closely related to clostridial acetogens were also active in soil-free Molinia and Carex root treatments with or without supplemental H2. Due to pronounced fermentation activities, H2 consumption was less obvious in root treatments, and acetogens likely thrived on root organic carbon and fermentation products (e.g., ethanol) in addition to H2. Collectively, the data highlighted that in fen Schlöppnerbrunnen, acetogens are associated to graminoid roots and inhabit the peat soil around the roots, where they have to compete for H2 with methanogens and iron reducers. Furthermore, the study underscored that the metabolically flexible acetogens do not rely on H2, potentially a key advantage over other H2 consumers under the highly dynamic conditions characteristic for the root-zones of graminoids in peatlands.
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Affiliation(s)
- Anja B. Meier
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
| | - Sindy Oppermann
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
| | - Harold L. Drake
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
| | - Oliver Schmidt
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
- *Correspondence: Oliver Schmidt,
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Wu D, Deng L, Sun Y, Wang R, Zhang L, Wang R, Song Y, Gao Z, Haider H, Wang Y, Hou L, Liu M. Climate warming, but not Spartina alterniflora invasion, enhances wetland soil HONO and NO x emissions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 823:153710. [PMID: 35149064 DOI: 10.1016/j.scitotenv.2022.153710] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/27/2022] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
Climate warming and invasive plant growth (plant invasion) may aggravate air pollution by affecting soil nitrogen (N) cycling and the emissions of reactive N gases, such as nitrous acid (HONO) and nitrogen oxides (NOx). However, little is known about the response of soil NOy (HONO + NOx) emissions and microbial functional genes to the interaction of climate warming and plant invasion. Here, we found that experimental warming (approximately 1.5 °C), but not Spartina alterniflora invasion, increased NOy emissions (0-140 ng N m-2 s-1) of treated wetland soils by 4-10 fold. Warming also decreased soil archaeal and fungal richness and diversity, shifted their community structure (e.g., decreased the archaeal classes Thermoplasmata and Iainarchaeia, and increased the archaeal genus Candidatus Nitrosoarchaeum, and the fungal classes Saccharomycetes and Tritirachiomycetes), and decreased the overall abundance of soil N cycling genes. Structural equation modeling revealed that warming-associated changes in edaphic factors and the microbial N cycling potential are responsible for the observed increase in soil NOy emissions. Collectively, the results showed that climate warming accelerates soil N cycling by stimulating large soil HONO and NOx emissions, and influences air quality by contributing to atmospheric reactive N and ozone cycling.
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Affiliation(s)
- Dianming Wu
- Key Laboratory of Geographic Information Science (Ministry of Education), School of Geographic Sciences, East China Normal University, 200241 Shanghai, China; Institute of Eco-Chongming (IEC), 202162 Shanghai, China.
| | - Lingling Deng
- Key Laboratory of Geographic Information Science (Ministry of Education), School of Geographic Sciences, East China Normal University, 200241 Shanghai, China
| | - Yihua Sun
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, 518060 Shenzhen, China
| | - Ruhai Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of soil Sciences, Chinese Academy of Sciences, 210008 Nanjing, China
| | - Li Zhang
- School of Resources and Environment, Anhui Agricultural University, 230036 Hefei, China
| | - Rui Wang
- Key Laboratory of Geographic Information Science (Ministry of Education), School of Geographic Sciences, East China Normal University, 200241 Shanghai, China
| | - Yaqi Song
- Key Laboratory of Geographic Information Science (Ministry of Education), School of Geographic Sciences, East China Normal University, 200241 Shanghai, China; College of Biology and the Environment, Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, 210037 Nanjing, China
| | - Zhiwei Gao
- Key Laboratory of Geographic Information Science (Ministry of Education), School of Geographic Sciences, East China Normal University, 200241 Shanghai, China
| | - Haroon Haider
- Key Laboratory of Geographic Information Science (Ministry of Education), School of Geographic Sciences, East China Normal University, 200241 Shanghai, China
| | - Yue Wang
- Key Laboratory of Geographic Information Science (Ministry of Education), School of Geographic Sciences, East China Normal University, 200241 Shanghai, China
| | - Lijun Hou
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, 200241 Shanghai, China
| | - Min Liu
- Key Laboratory of Geographic Information Science (Ministry of Education), School of Geographic Sciences, East China Normal University, 200241 Shanghai, China; Institute of Eco-Chongming (IEC), 202162 Shanghai, China
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Hetz SA, Horn MA. Burkholderiaceae Are Key Acetate Assimilators During Complete Denitrification in Acidic Cryoturbated Peat Circles of the Arctic Tundra. Front Microbiol 2021; 12:628269. [PMID: 33613495 PMCID: PMC7892595 DOI: 10.3389/fmicb.2021.628269] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 01/18/2021] [Indexed: 01/23/2023] Open
Abstract
Cryoturbated peat circles (pH 4) in the Eastern European Tundra harbor up to 2 mM pore water nitrate and emit the greenhouse gas N2O like heavily fertilized agricultural soils in temperate regions. The main process yielding N2O under oxygen limited conditions is denitrification, which is the sequential reduction of nitrate/nitrite to N2O and/or N2. N2O reduction to N2 is impaired by pH < 6 in classical model denitrifiers and many environments. Key microbes of peat circles are important but largely unknown catalysts for C- and N-cycling associated N2O fluxes. Thus, we hypothesized that the peat circle community includes hitherto unknown taxa and is essentially unable to efficiently perform complete denitrification, i.e., reduce N2O, due to a low in situ pH. 16S rRNA analysis indicated a diverse active community primarily composed of the bacterial class-level taxa Alphaproteobacteria, Acidimicrobiia, Acidobacteria, Verrucomicrobiae, and Bacteroidia, as well as archaeal Nitrososphaeria. Euryarchaeota were not detected. 13C2- and 12C2-acetate supplemented anoxic microcosms with endogenous nitrate and acetylene at an in situ near pH of 4 were used to assess acetate dependent carbon flow, denitrification and N2O production. Initial nitrate and acetate were consumed within 6 and 11 days, respectively, and primarily converted to CO2 and N2, suggesting complete acetate fueled denitrification at acidic pH. Stable isotope probing coupled to 16S rRNA analysis via Illumina MiSeq amplicon sequencing identified acetate consuming key players of the family Burkholderiaceae during complete denitrification correlating with Rhodanobacter spp. The archaeal community consisted primarily of ammonia-oxidizing Archaea of Nitrososphaeraceae, and was stable during the incubation. The collective data indicate that peat circles (i) host acid-tolerant denitrifiers capable of complete denitrification at pH 4-5.5, (ii) other parameters like carbon availability rather than pH are possible reasons for high N2O emissions in situ, and (iii) Burkholderiaceae are responsive key acetate assimilators co-occurring with Rhodanobacter sp. during denitrification, suggesting both organisms being associated with acid-tolerant denitrification in peat circles.
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Affiliation(s)
- Stefanie A Hetz
- Institute of Microbiology, Leibniz University Hannover, Hannover, Germany
| | - Marcus A Horn
- Institute of Microbiology, Leibniz University Hannover, Hannover, Germany
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6
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Wen X, Hu C, Sun X, Zhao X, Tan Q. Research on the nitrogen transformation in rhizosphere of winter wheat (Triticum aestivum) under molybdenum addition. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:2363-2374. [PMID: 30467748 DOI: 10.1007/s11356-018-3565-y] [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: 07/21/2017] [Accepted: 10/22/2018] [Indexed: 06/09/2023]
Abstract
Molybdenum (Mo), an essential microelement for plants, animals, and microorganisms, is reported can reduce soil nitrogen (N) residues and regulate plant root growth, but little is known about its effect on soil N transformation in plant-root region. A specially designed rhizobox was used in the present study to investigate the N processes in rhizosphere and non-rhizosphere soils of winter wheat applied with different rates of Mo fertilizer. (1) In the rhizosphere soil, pH values increased with increasing rates of Mo application, nitrate (NO3--N) accumulated at the rates of 0.15 and 0.3 mg Mo kg-1, potential denitrification activity (PDA) was significantly reduced by application of 0.15-1 mg Mo kg-1, and the copy numbers of narG and nosZ genes were increased by application of 0.15-1 mg Mo kg-1. (2) In the non-rhizosphere soil, NO3--N content decreased by application of 0.15-0.3 mg Mo kg-1, and narG gene abundance increased obviously by application of 0.3-1 mg Mo kg-1. (3) Soil pH, NO3--N, apparent nitrification rate (ANR), and nosZ gene abundance were significantly higher in rhizosphere than in non-rhizosphere soil. On the contrary, NH4+-N and total N, PDA, the abundance of AOB, and nirK and nirS genes were significantly higher in non-rhizosphere soil. The results indicated that the N transformations in rhizosphere and non-rhizosphere soils were differently affected by soil application of Mo fertilizer, and rhizosphere played a more important role in soil N cycle processes. The regulatory effects of Mo on these processes were to increase plant biomass and N uptake, promote the NO3--N accumulation in rhizosphere soil, and weaken the denitrification in both rhizosphere and non-rhizosphere soils.
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Affiliation(s)
- Xin Wen
- Department of Resource and Environment/Hubei Provincial Engineering Laboratory for New Fertilizers/Research Center of Trace Elements, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Horticultural Plant Biology (HZAU), MOE, Huazhong Agricultural University, Wuhan, 430070, China
| | - Chengxiao Hu
- Department of Resource and Environment/Hubei Provincial Engineering Laboratory for New Fertilizers/Research Center of Trace Elements, Huazhong Agricultural University, Wuhan, 430070, China.
- Key Laboratory of Horticultural Plant Biology (HZAU), MOE, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Xuecheng Sun
- Department of Resource and Environment/Hubei Provincial Engineering Laboratory for New Fertilizers/Research Center of Trace Elements, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xiaohu Zhao
- Department of Resource and Environment/Hubei Provincial Engineering Laboratory for New Fertilizers/Research Center of Trace Elements, Huazhong Agricultural University, Wuhan, 430070, China
| | - Qiling Tan
- Department of Resource and Environment/Hubei Provincial Engineering Laboratory for New Fertilizers/Research Center of Trace Elements, Huazhong Agricultural University, Wuhan, 430070, China
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Meng Q, Xu X, Zhang W, Cheng L, Men M, Xu B, Deng L, Sun X. Diversity and abundance of denitrifiers during cow manure composting. Rev Argent Microbiol 2018; 51:191-200. [PMID: 30467018 DOI: 10.1016/j.ram.2018.08.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 07/17/2018] [Accepted: 08/06/2018] [Indexed: 10/27/2022] Open
Abstract
Diversity and abundance of the denitrifying genes nirK, nirS and nosZ were investigated in cow manure compost using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and real-time quantitative PCR (qPCR), respectively. These three genes were detected in all the stages of the composting process. Phylogenetic analysis showed that the nirK gene was closely related to Rhizobiales, Burkholderiales, the nirS gene was closely related to Pseudomonadales and Burkholderiales, and the nosZ gene was closely related to Rhodospirillales, Rhizobiales, Pseudomonadales, and Alteromonadales. qPCR results showed that the abundance of these three genes (nirK, nirS and nosZ) reached the peak value in the late thermophilic stage of composting and abundance of the nirK gene was higher than that of the nosZ gene and the nirS gene. Redundancy analysis (RDA) showed that the diversity of the nirK and nirS genes was significantly correlated with ammonium (p<0.05), the diversity of the nosZ gene was significantly correlated with pH (p<0.05) and the abundance of the nirK nirS and nosZ genes was significantly correlated with temperature (p<0.05).
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Affiliation(s)
- Qingxin Meng
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, China
| | - Xiuhong Xu
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, China.
| | - Wenhao Zhang
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, China
| | - Lijun Cheng
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, China
| | - Mengqi Men
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, China
| | - Benshu Xu
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, China
| | - Liting Deng
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, China
| | - Xuewei Sun
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, China
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8
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Ge X, Vaccaro BJ, Thorgersen MP, Poole FL, Majumder EL, Zane GM, De León KB, Lancaster WA, Moon JW, Paradis CJ, von Netzer F, Stahl DA, Adams PD, Arkin AP, Wall JD, Hazen TC, Adams MWW. Iron- and aluminium-induced depletion of molybdenum in acidic environments impedes the nitrogen cycle. Environ Microbiol 2018; 21:152-163. [PMID: 30289197 DOI: 10.1111/1462-2920.14435] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/24/2018] [Accepted: 09/27/2018] [Indexed: 11/25/2022]
Abstract
Anthropogenic nitrate contamination is a serious problem in many natural environments. Nitrate removal by microbial action is dependent on the metal molybdenum (Mo), which is required by nitrate reductase for denitrification and dissimilatory nitrate reduction to ammonium. The soluble form of Mo, molybdate (MoO4 2- ), is incorporated into and adsorbed by iron (Fe) and aluminium (Al) (oxy) hydroxide minerals. Herein we used Oak Ridge Reservation (ORR) as a model nitrate-contaminated acidic environment to investigate whether the formation of Fe- and Al-precipitates could impede microbial nitrate removal by depleting Mo. We demonstrate that Fe and Al mineral formation that occurs as the pH of acidic synthetic groundwater is increased, decreases soluble Mo to low picomolar concentrations, a process proposed to mimic environmental diffusion of acidic contaminated groundwater. Analysis of ORR sediments revealed recalcitrant Mo in the contaminated core that co-occurred with Fe and Al, consistent with Mo scavenging by Fe/Al precipitates. Nitrate removal by ORR isolate Pseudomonas fluorescens N2A2 is virtually abolished by Fe/Al precipitate-induced Mo depletion. The depletion of naturally occurring Mo in nitrate- and Fe/Al-contaminated acidic environments like ORR or acid mine drainage sites has the potential to impede microbial-based nitrate reduction thereby extending the duration of nitrate in the environment.
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Affiliation(s)
- Xiaoxuan Ge
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Brian J Vaccaro
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Michael P Thorgersen
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Farris L Poole
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Erica L Majumder
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, USA
| | - Grant M Zane
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, USA
| | - Kara B De León
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, USA
| | - W Andrew Lancaster
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Ji Won Moon
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Charles J Paradis
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN, 37996, USA
| | - Frederick von Netzer
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, 98495, USA
| | - David A Stahl
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, 98495, USA
| | - Paul D Adams
- Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Adam P Arkin
- Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Judy D Wall
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, USA
| | - Terry C Hazen
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN, 37996, USA
| | - Michael W W Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
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Liu Y, Zhu J, Ye C, Zhu P, Ba Q, Pang J, Shu L. Effects of biochar application on the abundance and community composition of denitrifying bacteria in a reclaimed soil from coal mining subsidence area. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 625:1218-1224. [PMID: 29996418 DOI: 10.1016/j.scitotenv.2018.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 12/30/2017] [Accepted: 01/01/2018] [Indexed: 06/08/2023]
Abstract
As a new soil amendment, biochar has become an environmentally friendly material. The application of biochar is one of the most promising management practice to improve soil quality. Using a reclaimed soil from a coal mine subsidence area, the plat soil cultivation experiment in this study investigated the effects of biochar application at varying rates on soil properties, the abundance and composition of soil denitrifier communities. Biochar application significantly increased the crop yield which might be associated with the increased level of cation exchange capacity (CEC), total nitrogen (N), ammonium-N, available phosphorus (P) and potassium (K) in soil. In combination with N fertilizer, the abundance of both nirK and nirS genes significantly increased only at biochar application rate of 4% compared with the nil-biochar treatment. Biochar application significantly increased the community diversity of nirK gene, while not for nirS gene. Redundancy analysis showed that the level of nitrate-N (NO3--N), available P, and pH in soil significantly affected community structure of nirK gene, while the nirS community composition was only affected by soil NO3--N level. Our results indicate that biochar application to the reclaimed soil in coal mine subsidence area could influence the abundance and diversity of soil denitrifiers and improve soil nutrients thus crop yield.
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Affiliation(s)
- Yuan Liu
- College of Life Sciences, Huaibei Normal University, Anhui Key Laboratory of Resource and Plant Biology, Huaibei 235000, China
| | - Jirong Zhu
- College of Life Sciences, Huaibei Normal University, Anhui Key Laboratory of Resource and Plant Biology, Huaibei 235000, China
| | - Chengyu Ye
- College of Life Sciences, Huaibei Normal University, Anhui Key Laboratory of Resource and Plant Biology, Huaibei 235000, China
| | - Pengfei Zhu
- College of Life Sciences, Huaibei Normal University, Anhui Key Laboratory of Resource and Plant Biology, Huaibei 235000, China
| | - Qingsong Ba
- College of Life Sciences, Huaibei Normal University, Anhui Key Laboratory of Resource and Plant Biology, Huaibei 235000, China
| | - Jiayin Pang
- School of Agriculture and Environment and Institute of Agriculture, University of Western Australia, Crawley, Perth, WA 6009, Australia
| | - Liangzuo Shu
- College of Life Sciences, Huaibei Normal University, Anhui Key Laboratory of Resource and Plant Biology, Huaibei 235000, China.
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10
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Meng H, Wu R, Wang YF, Gu JD. A comparison of denitrifying bacterial community structures and abundance in acidic soils between natural forest and re-vegetated forest of Nanling Nature Reserve in southern China. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2017; 198:41-49. [PMID: 28500915 DOI: 10.1016/j.jenvman.2017.04.066] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 04/02/2017] [Accepted: 04/22/2017] [Indexed: 06/07/2023]
Abstract
Denitrification plays a key role in converting reactive nitrogen species to dinitrogen gas back into the atmosphere to maintain the equilibrium of nitrogen cycling in ecosystems. In this study, functional genes of nirK and nosZ were used to detect the community structure and abundance of denitrifying microorganisms in acidic forest soils in southern China. Three sets of factors were considered for a comparison among 5 forests, including forest types (natural vs. re-vegetated), depths (surface layer vs. lower layer) and seasons (winter vs. summer). The community of nirK gene detected from these acidic forest soils was closely related to Proteobacteria especially α-Proteobacteria and uncultured soil sequences, while that of nosZ gene was affiliated with the α-, β- and γ-Proteobacteria. Higher diversity of denitrifiers was observed in re-vegetated forest soils than natural ones. Not only the community but also the abundance showed significant differences between forest types as well as depths. The abundance of denitrifiers ranged from 105 to 107 gene copies g-1 dry soil in this study. For nirK gene, the abundance was much higher in the lower layer than surface layer in both forest types, and the differences between winter and summer in natural forest soils were higher than those in re-vegetated forest soils. The abundance of nosZ and nirK genes showed a similar trend in natural forest, but the former was higher in matured forest than re-vegetated forest. This study provided a direct comparison on community composition and abundance of denitrifying bacteria in natural and re-vegetated acidic forest soils to allow further assessment of the nitrogen cycling.
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Affiliation(s)
- Han Meng
- Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, Faculty of Science, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Ruonan Wu
- Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, Faculty of Science, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Yong-Feng Wang
- Guangdong Provincial Key Laboratory of Silviculture, Protection and Utilization, Guangdong Academy of Forestry, No. 233, Guangshan 1st Road, Guangzhou, 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, China.
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11
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Zhang Z, Zhang W, Yang H, Sheng R, Wei W, Qin H. Elevated N 2O emission by the rice roots: based on the abundances of narG and bacterial amoA genes. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:2116-2125. [PMID: 27812967 DOI: 10.1007/s11356-016-7993-2] [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: 03/03/2016] [Accepted: 10/25/2016] [Indexed: 06/06/2023]
Abstract
Rice fields are an important source of nitrous oxide (N2O), where rice plants could act as a key factor controlling N2O fluxes during the flooding-drying process; however, the microbial driving mechanisms are unclear. In this study, specially designed equipment was used to grow rice plants and collect emitted N2O from the root-growing zone (zone A), root-free zones (zones B, C, and D) independently, at tillering and booting stages under flooding and drying conditions. Soil samples from the four zones were also taken separately. Nitrifying and denitrifying community abundances were detected using quantitative polymerase chain reaction (qPCR). The N2O emission increased significantly along with drying, but the N2O emission capabilities varied among the four zones under drying, while zone B possessed the highest N2O fluxes that were 2.7~4.5 times higher than those from zones C and D. However, zone A showed N2O consumption potential. Notably, zone B also harbored the highest numbers of narG-containing denitrifiers and amoA-containing nitrifiers under drying at both tillering and booting stages. This study demonstrates that drying caused significant increase in N2O emission from rhizosphere soil, in which the higher abundance of AOB would help to produce more nitrate and significantly higher narG-containing microbes would drive more N2O production and emission.
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Affiliation(s)
- Zhenxing Zhang
- Key Laboratory of Agro-ecological Processes in Subtropical Region and Taoyuan Agro-ecosystem Research Station, Soil Molecular Ecology Section, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
- Graduate University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wenzhao Zhang
- Key Laboratory of Agro-ecological Processes in Subtropical Region and Taoyuan Agro-ecosystem Research Station, Soil Molecular Ecology Section, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
| | - Huicui Yang
- Key Laboratory of Agro-ecological Processes in Subtropical Region and Taoyuan Agro-ecosystem Research Station, Soil Molecular Ecology Section, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
- Graduate University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Rong Sheng
- Key Laboratory of Agro-ecological Processes in Subtropical Region and Taoyuan Agro-ecosystem Research Station, Soil Molecular Ecology Section, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
| | - Wenxue Wei
- Key Laboratory of Agro-ecological Processes in Subtropical Region and Taoyuan Agro-ecosystem Research Station, Soil Molecular Ecology Section, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
| | - Hongling Qin
- Key Laboratory of Agro-ecological Processes in Subtropical Region and Taoyuan Agro-ecosystem Research Station, Soil Molecular Ecology Section, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China.
- Graduate University of Chinese Academy of Sciences, Beijing, 100049, China.
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Palmer K, Köpp J, Gebauer G, Horn MA. Drying-Rewetting and Flooding Impact Denitrifier Activity Rather than Community Structure in a Moderately Acidic Fen. Front Microbiol 2016; 7:727. [PMID: 27313566 PMCID: PMC4887476 DOI: 10.3389/fmicb.2016.00727] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 05/02/2016] [Indexed: 02/04/2023] Open
Abstract
Wetlands represent sources or sinks of the greenhouse gas nitrous oxide (N2O). The acidic fen Schlöppnerbrunnen emits denitrification derived N2O and is also capable of N2O consumption. Global warming is predicted to cause more extreme weather events in future years, including prolonged drought periods as well as heavy rainfall events, which may result in flooding. Thus, the effects of prolonged drought and flooding events on the abundance, community composition, and activity of fen denitrifiers were investigated in manipulation experiments. The water table in the fen was experimentally lowered for 8 weeks in 2008 and raised for 5.5 months in 2009 on three treatment plots, while three plots were left untreated and served as controls. In situ N2O fluxes were rather unaffected by the drought treatment and were marginally increased by the flooding treatment. Samples were taken before and after treatment in both years. The structural gene markers narG and nosZ were used to assess possible changes in the nitrate reducer and denitrifier community in response to water table manipulations. Detected copy numbers of narG and nosZ were essentially unaffected by the experimental drought and flooding. Terminal restriction fragment length polymorphism (TRFLP) patterns of narG and nosZ were similar before and after experimental drought or experimental flooding, indicating a stable nitrate reducer and denitrifier community in the fen. However, certain TRFs of narG and nosZ transcripts responded to experimental drought or flooding. Nitrate-dependent Michaelis-Menten kinetics were assessed in anoxic microcosms with peat samples taken before and 6 months after the onset of experimental flooding. Maximal reaction velocities vmax were higher after than before flooding in samples from treament but not in those from control plots taken at the same time. The ratio of N2O to N2O + N2 was lower in soil from treatment plots after flooding than in soil from control plots, suggesting mitigation of N2O emissions by increased N2O-reduction rates after flooding. N2O was consumed to subatmospheric levels in all microcosms after flooding. The collective data indicate that water table manipulations had only minor effects on in situ N2O fluxes, denitrifier abundance, and denitrifier community composition of the acidic fen, while active subpopulations of denitrifiers changed in response to water table manipulations, suggesting functionally redundant subpopulations occupying distinct ecological niches in the fen.
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Affiliation(s)
- Katharina Palmer
- Department of Ecological Microbiology, University of BayreuthBayreuth, Germany; Water Resources and Environmental Engineering Research Group, University of OuluOulu, Finland
| | - Julia Köpp
- BayCEER-Laboratory of Isotope Biogeochemistry, University of Bayreuth Bayreuth, Germany
| | - Gerhard Gebauer
- BayCEER-Laboratory of Isotope Biogeochemistry, University of Bayreuth Bayreuth, Germany
| | - Marcus A Horn
- Department of Ecological Microbiology, University of Bayreuth Bayreuth, Germany
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13
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Braker G, Conrad R. Diversity, structure, and size of N(2)O-producing microbial communities in soils--what matters for their functioning? ADVANCES IN APPLIED MICROBIOLOGY 2016; 75:33-70. [PMID: 21807245 DOI: 10.1016/b978-0-12-387046-9.00002-5] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Nitrous oxide (N(2)O) is mainly generated via nitrification and denitrification processes in soils and subsequently emitted into the atmosphere where it causes well-known radiative effects. How nitrification and denitrification are affected by proximal and distal controls has been studied extensively in the past. The importance of the underlying microbial communities, however, has been acknowledged only recently. Particularly, the application of molecular methods to study nitrifiers and denitrifiers directly in their habitats enabled addressing how environmental factors influence the diversity, community composition, and size of these functional groups in soils and whether this is of relevance for their functioning and N(2)O production. In this review, we summarize the current knowledge on community-function interrelationships. Aerobic nitrification (ammonia oxidation) and anaerobic denitrification are clearly under different controls. While N(2)O is an obligatory intermediate in denitrification, its production during ammonia oxidation depends on whether nitrite, the end product, is further reduced. Moreover, individual strains vary strongly in their responses to environmental cues, and so does N(2)O production. We therefore conclude that size and structure of both functional groups are relevant with regard to production and emission of N(2)O from soils. Diversity affects on function, however, are much more difficult to assess, as it is not resolved as yet how individual nitrification or denitrification genotypes are related to N(2)O production. More research is needed for further insights into the relation of microbial communities to ecosystem functions, for instance, how the actively nitrifying or denitrifying part of the community may be related to N(2)O emission.
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Affiliation(s)
- Gesche Braker
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, Marburg, Germany.
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14
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Schmidt O, Hink L, Horn MA, Drake HL. Peat: home to novel syntrophic species that feed acetate- and hydrogen-scavenging methanogens. ISME JOURNAL 2016; 10:1954-66. [PMID: 26771931 DOI: 10.1038/ismej.2015.256] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 11/25/2015] [Accepted: 12/07/2015] [Indexed: 11/09/2022]
Abstract
Syntrophic bacteria drive the anaerobic degradation of certain fermentation products (e.g., butyrate, ethanol, propionate) to intermediary substrates (e.g., H2, formate, acetate) that yield methane at the ecosystem level. However, little is known about the in situ activities and identities of these syntrophs in peatlands, ecosystems that produce significant quantities of methane. The consumption of butyrate, ethanol or propionate by anoxic peat slurries at 5 and 15 °C yielded methane and CO2 as the sole accumulating products, indicating that the intermediates H2, formate and acetate were scavenged effectively by syntrophic methanogenic consortia. 16S rRNA stable isotope probing identified novel species/strains of Pelobacter and Syntrophomonas that syntrophically oxidized ethanol and butyrate, respectively. Propionate was syntrophically oxidized by novel species of Syntrophobacter and Smithella, genera that use different propionate-oxidizing pathways. Taxa not known for a syntrophic metabolism may have been involved in the oxidation of butyrate (Telmatospirillum-related) and propionate (unclassified Bacteroidetes and unclassified Fibrobacteres). Gibbs free energies (ΔGs) for syntrophic oxidations of ethanol and butyrate were more favorable than ΔGs for syntrophic oxidation of propionate. As a result of the thermodynamic constraints, acetate transiently accumulated in ethanol and butyrate treatments but not in propionate treatments. Aceticlastic methanogens (Methanosarcina, Methanosaeta) appeared to outnumber hydrogenotrophic methanogens (Methanocella, Methanoregula), reinforcing the likely importance of aceticlastic methanogenesis to the overall production of methane. ΔGs for acetogenesis from H2 to CO2 approximated to -20 kJ mol(-1) when acetate concentrations were low, indicating that acetogens may have contributed to the flow of carbon and reductant towards methane.
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Affiliation(s)
- Oliver Schmidt
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
| | - Linda Hink
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
| | - Marcus A Horn
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
| | - Harold L Drake
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
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15
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Nie Y, Li L, Wang M, Tahvanainen T, Hashidoko Y. Nitrous oxide emission potentials of Burkholderia species isolated from the leaves of a boreal peat moss Sphagnum fuscum*. Biosci Biotechnol Biochem 2015; 79:2086-95. [DOI: 10.1080/09168451.2015.1061420] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Abstract
Using a culture-based nitrous oxide (N2O) emission assay, three active N2O emitters were isolated from Sphagnum fuscum leaves and all identified as members of Burkholderia. These isolates showed N2O emission in the medium supplemented with but not with , and Burkholderia sp. SF-E2 showed the most efficient N2O emission (0.20 μg·vial−1·day−1) at 1.0 mM KNO3. In Burkholderia sp. SF-E2, the optimum pH for N2O production was 5.0, close to that of the phyllosphere of Sphagnum mosses, while the optimum temperature was uniquely over 30 °C. The stimulating effect of additional 1.5 mM sucrose on N2O emission was ignorable, but Burkholderia sp. SF-E2 upon exposure to 100 mg·L−1 E-caffeic acid showed uniquely 67-fold higher N2O emission. All of the three N2O emitters were negative in both acetylene inhibition assay and PCR assay for nosZ-detection, suggesting that N2O reductase or the gene itself is missing in the N2O-emitting Burkholderia.
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Affiliation(s)
- Yanxia Nie
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Li Li
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Mengcen Wang
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
- Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou, China
| | - Teemu Tahvanainen
- Department of Biology, University of Eastern Finland, Joensuu, Finland
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16
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Brenzinger K, Dörsch P, Braker G. pH-driven shifts in overall and transcriptionally active denitrifiers control gaseous product stoichiometry in growth experiments with extracted bacteria from soil. Front Microbiol 2015; 6:961. [PMID: 26441895 PMCID: PMC4585170 DOI: 10.3389/fmicb.2015.00961] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 08/31/2015] [Indexed: 01/27/2023] Open
Abstract
Soil pH is a strong regulator for activity as well as for size and composition of denitrifier communities. Low pH not only lowers overall denitrification rates but also influences denitrification kinetics and gaseous product stoichiometry. N2O reductase is particularly sensitive to low pH which seems to impair its activity post-transcriptionally, leading to higher net N2O production. Little is known about how complex soil denitrifier communities respond to pH change and whether their ability to maintain denitrification over a wider pH range relies on phenotypic redundancy. In the present study, we followed the abundance and composition of an overall and transcriptionally active denitrifier community extracted from a farmed organic soil in Sweden (pHH2O = 7.1) when exposed to pH 5.4 and drifting back to pH 6.6. The soil was previously shown to retain much of its functioning (low N2O/N2 ratios) over a wide pH range, suggesting a high functional versatility of the underlying community. We found that denitrifier community composition, abundance and transcription changed throughout incubation concomitant with pH change in the medium, allowing for complete reduction of nitrate to N2 with little accumulation of intermediates. When exposed to pH 5.4, the denitrifier community was able to grow but reduced N2O to N2 only when near-neutral pH was reestablished by the alkalizing metabolic activity of an acid-tolerant part of the community. The genotypes proliferating under these conditions differed from those dominant in the control experiment run at neutral pH. Denitrifiers of the nirS-type appeared to be severely suppressed by low pH and nirK-type and nosZ-containing denitrifiers showed strongly reduced transcriptional activity and growth, even after restoration of neutral pH. Our study suggests that low pH episodes alter transcriptionally active populations which shape denitrifier communities and determine their gas kinetics.
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Affiliation(s)
- Kristof Brenzinger
- Department of Biogeochemistry, Max Planck Institute for Terrestrial Microbiology Marburg, Germany
| | - Peter Dörsch
- Department of Environmental Sciences, Norwegian University of Life Sciences Ås, Norway
| | - Gesche Braker
- Department of Biogeochemistry, Max Planck Institute for Terrestrial Microbiology Marburg, Germany ; University of Kiel Kiel, Germany
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17
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Palmer K, Horn MA. Denitrification activity of a remarkably diverse fen denitrifier community in finnish lapland is N-oxide limited. PLoS One 2015; 10:e0123123. [PMID: 25860353 PMCID: PMC4393310 DOI: 10.1371/journal.pone.0123123] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 01/21/2015] [Indexed: 11/23/2022] Open
Abstract
Peatlands cover more than 30% of the Finnish land area and impact N2O fluxes. Denitrifiers release N2O as an intermediate or end product. In situ N2O emissions of a near pH neutral pristine fen soil in Finnish Lapland were marginal during gas chamber measurements. However, nitrate and ammonium fertilization significantly stimulated in situ N2O emissions. Stimulation with nitrate was stronger than with ammonium. N2O was produced and subsequently consumed in gas chambers. In unsupplemented anoxic microcosms, fen soil produced N2O only when acetylene was added to block nitrous oxide reductase, suggesting complete denitrification. Nitrate and nitrite stimulated denitrification in fen soil, and maximal reaction velocities (vmax) of nitrate or nitrite dependent denitrification where 18 and 52 nmol N2O h-1 gDW-1, respectively. N2O was below 30% of total produced N gases in fen soil when concentrations of nitrate and nitrite were <500 μM. vmax for N2O consumption was up to 36 nmol N2O h-1 gDW-1. Denitrifier diversity was assessed by analyses of narG, nirK/nirS, and nosZ (encoding nitrate-, nitrite-, and nitrous oxide reductases, respectively) by barcoded amplicon pyrosequencing. Analyses of ~14,000 quality filtered sequences indicated up to 25 species-level operational taxonomic units (OTUs), and up to 359 OTUs at 97% sequence similarity, suggesting diverse denitrifiers. Phylogenetic analyses revealed clusters distantly related to publicly available sequences, suggesting hitherto unknown denitrifiers. Representatives of species-level OTUs were affiliated with sequences of unknown soil bacteria and Actinobacterial, Alpha-, Beta-, Gamma-, and Delta-Proteobacterial sequences. Comparison of the 4 gene markers at 97% similarity indicated a higher diversity of narG than for the other gene markers based on Shannon indices and observed number of OTUs. The collective data indicate (i) a high denitrification and N2O consumption potential, and (ii) a highly diverse, nitrate limited denitrifier community associated with potential N2O fluxes in a pH-neutral fen soil.
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Affiliation(s)
- Katharina Palmer
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
| | - Marcus A. Horn
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
- * E-mail:
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Huang Y, Long XE, Chapman SJ, Yao H. Acidophilic denitrifiers dominate the N2O production in a 100-year-old tea orchard soil. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:4173-4182. [PMID: 25273518 DOI: 10.1007/s11356-014-3653-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 09/23/2014] [Indexed: 06/03/2023]
Abstract
Aerobic denitrification is the main process for high N2O production in acid tea field soil. However, the biological mechanisms for the high emission are not fully understood. In this study, we examined N2O emission and denitrifier communities in 100-year-old tea soils with four pH levels (3.71, 5.11, 6.19, and 7.41) and four nitrate concentration (0, 50, 200, and 1000 mg kg(-1) of NO3 (-)-N) addition. Results showed the highest N2O emission (10.1 mg kg(-1) over 21 days) from the soil at pH 3.71 with 1000 mg kg(-1) NO3 (-) addition. The N2O reduction and denitrification enzyme activity in the acid soils (pH <7.0) were significantly higher than that of soils at pH 7.41. Moreover, TRF 78 of nirS and TRF 187 of nosZ dominated in soils of pH 3.71, suggesting an important role of acidophilic denitrifiers in N2O production and reduction. CCA analysis also showed a negative correlation between the dominant denitrifier ecotypes (nirS TRF 78, nosZ TRF 187) and soil pH. The representative sequences were identical to those of cultivated denitrifiers from acidic soils via phylogenetic tree analysis. Our results showed that the acidophilic denitrifier adaptation to the acid environment results in high N2O emission in this highly acidic tea soil.
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Affiliation(s)
- Ying Huang
- Institute of Urban Environment, Chinese Academy of Sciences, No. 1799 Jimei Road, Xiamen, 361021, China
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19
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Tauchnitz N, Spott O, Russow R, Bernsdorf S, Glaser B, Meissner R. Release of nitrous oxide and dinitrogen from a transition bog under drained and rewetted conditions due to denitrification: results from a [15N]nitrate-bromide double-tracer study. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2015; 51:300-321. [PMID: 25692907 DOI: 10.1080/10256016.2015.1011634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Denitrification is well known being the most important nitrate-consuming process in water-logged peat soils, whereby the intermediate compound nitrous oxide (N(2)O) and the end product dinitrogen (N(2)) are ultimately released. The present study was aimed at evaluating the release of these gases (due to denitrification) from a nutrient-poor transition bog ecosystem under drained and three differently rewetted conditions at the field scale using a (15)N-tracer approach ([(15)N]nitrate application, 30 kg N ha(-1)) and a common closed-chamber technique. The drained site is characterized by a constant water table (WT) of -30 cm (here referred to as D30), while rewetted sites represent a constant WT of -15 cm, a constant WT of 0 cm (i.e. waterlogged), and an initial WT of 0 cm (which decreased slightly during the experiment), respectively, (here referred to as R15, R0, and R0(d), respectively). The highest N(2)O emissions were observed at D30 (291 µg N(2)O-N m(-2) h(-1)) as well as at R0d (665 µg N(2)O-N m(-2) h(-1)). At the rewetted peat sites with a constant WT (i.e. R15 and R0), considerably lower N2O emissions were observed (maximal 37 µg N(2)O-N m(-2) h(-1)). Concerning N(2) only at the initially water-logged peat site R0d considerable release rates (up to 3110 µg N(2)-N m(-2) h(-1)) were observed, while under drained conditions (D30) no N(2) emission and under rewetted conditions with a constant WT (R15 and R0) significantly lower N(2) release rates (maximal 668 µg N(2)-N m(-2) h(-1)) could be detected. In addition, it has been found that natural WT fluctuations at rewetted peat sites, in particular a rapid drop down of the WT, can induce high emission rates for both N(2)O and N(2).
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Affiliation(s)
- Nadine Tauchnitz
- a Department 25, Agro ecology and EU attended Monitoring , State Institute for Agriculture, Forestry and Horticulture Saxony-Anhalt , Bernburg , Germany
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20
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Schmidt O, Horn MA, Kolb S, Drake HL. Temperature impacts differentially on the methanogenic food web of cellulose-supplemented peatland soil. Environ Microbiol 2014; 17:720-34. [PMID: 24813682 DOI: 10.1111/1462-2920.12507] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 05/07/2014] [Indexed: 11/29/2022]
Abstract
The impact of temperature on the largely unresolved intermediary ecosystem metabolism and associated unknown microbiota that link cellulose degradation and methane production in soils of a moderately acidic (pH 4.5) fen was investigated. Supplemental [(13) C]cellulose stimulated the accumulation of propionate, acetate and carbon dioxide as well as initial methane production in anoxic peat soil slurries at 15°C and 5°C. Accumulation of organic acids at 15°C was twice as fast as that at 5°C. 16S rRNA [(13) C]cellulose stable isotope probing identified novel unclassified Bacteria (79% identity to the next cultured relative Fibrobacter succinogenes), unclassified Bacteroidetes (89% identity to Prolixibacter bellariivorans), Porphyromonadaceae, Acidobacteriaceae and Ruminococcaceae as main anaerobic degraders of cellulose-derived carbon at both 15°C and 5°C. Holophagaceae and Spirochaetaceae were more abundant at 15°C. Clostridiaceae dominated the degradation of cellulose-derived carbon only at 5°C. Methanosarcina was the dominant methanogenic taxa at both 15°C and 5°C. Relative abundance of Methanocella increased at 15°C whereas that of Methanoregula and Methanosaeta increased at 5°C. Thaumarchaeota closely related to Nitrosotalea (presently not known to grow anaerobically) were abundant at 5°C but absent at 15°C indicating that Nitrosotalea sp. might be capable of anaerobic growth at low temperatures in peat.
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Affiliation(s)
- Oliver Schmidt
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, 95440, Germany
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Schreiber F, Wunderlin P, Udert KM, Wells GF. Nitric oxide and nitrous oxide turnover in natural and engineered microbial communities: biological pathways, chemical reactions, and novel technologies. Front Microbiol 2012; 3:372. [PMID: 23109930 PMCID: PMC3478589 DOI: 10.3389/fmicb.2012.00372] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 09/28/2012] [Indexed: 12/20/2022] Open
Abstract
Nitrous oxide (N(2)O) is an environmentally important atmospheric trace gas because it is an effective greenhouse gas and it leads to ozone depletion through photo-chemical nitric oxide (NO) production in the stratosphere. Mitigating its steady increase in atmospheric concentration requires an understanding of the mechanisms that lead to its formation in natural and engineered microbial communities. N(2)O is formed biologically from the oxidation of hydroxylamine (NH(2)OH) or the reduction of nitrite (NO(-) (2)) to NO and further to N(2)O. Our review of the biological pathways for N(2)O production shows that apparently all organisms and pathways known to be involved in the catabolic branch of microbial N-cycle have the potential to catalyze the reduction of NO(-) (2) to NO and the further reduction of NO to N(2)O, while N(2)O formation from NH(2)OH is only performed by ammonia oxidizing bacteria (AOB). In addition to biological pathways, we review important chemical reactions that can lead to NO and N(2)O formation due to the reactivity of NO(-) (2), NH(2)OH, and nitroxyl (HNO). Moreover, biological N(2)O formation is highly dynamic in response to N-imbalance imposed on a system. Thus, understanding NO formation and capturing the dynamics of NO and N(2)O build-up are key to understand mechanisms of N(2)O release. Here, we discuss novel technologies that allow experiments on NO and N(2)O formation at high temporal resolution, namely NO and N(2)O microelectrodes and the dynamic analysis of the isotopic signature of N(2)O with quantum cascade laser absorption spectroscopy (QCLAS). In addition, we introduce other techniques that use the isotopic composition of N(2)O to distinguish production pathways and findings that were made with emerging molecular techniques in complex environments. Finally, we discuss how a combination of the presented tools might help to address important open questions on pathways and controls of nitrogen flow through complex microbial communities that eventually lead to N(2)O build-up.
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Affiliation(s)
- Frank Schreiber
- Department of Environmental Microbiology, Eawag - Swiss Federal Institute of Aquatic Science and Technology Dübendorf, Switzerland ; Department of Environmental Systems Sciences, Eidgenössische Technische Hochschule Zurich, Switzerland
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Herrmann M, Hädrich A, Küsel K. Predominance of thaumarchaeal ammonia oxidizer abundance and transcriptional activity in an acidic fen. Environ Microbiol 2012; 14:3013-25. [PMID: 23016896 DOI: 10.1111/j.1462-2920.2012.02882.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 08/23/2012] [Indexed: 11/27/2022]
Abstract
We investigated the abundance, community composition and transcriptional activity of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in the acidic fen Schlöppnerbrunnen (Germany) that was subjected to water table manipulations. Quantitative PCR targeting amoA gene copies and transcripts showed that AOA dominated the ammonia-oxidizing community in the upper 20 cm of the peat soil. Numbers of archaeal amoA gene copies and transcripts as well as the relative fraction of AOA of the total archaea decreased with depth. AOA-AmoA sequences were 96.2-98.9% identical to that of Candidatus Nitrosotalea devanaterra while bacterial AmoA sequences affiliated with Nitrosospira clusters 2 and 4. Archaeal but not bacterial amoA transcripts were detected in short-term laboratory incubations of peat that showed nitrifying activity. Nitrate accumulated in the peat pore water after 6 weeks of induced drought during a field experiment. Subsequent rewetting resulted in a significant decrease of AOA transcriptional activity, indicating that AOA responded to water table fluctuations on the transcriptional level. Our results suggest that nitrification in this fen is primarily linked to archaeal ammonia oxidation. pH and anoxia appear to be key factors regulating AOA community composition, vertical distribution and activity in acidic fens.
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Affiliation(s)
- Martina Herrmann
- Aquatic Geomicrobiology Group, Institute of Ecology, Friedrich Schiller University Jena, Dornburger Strasse 159, D-07743 Jena, Germany.
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Actinobacterial nitrate reducers and proteobacterial denitrifiers are abundant in N2O-metabolizing palsa peat. Appl Environ Microbiol 2012; 78:5584-96. [PMID: 22660709 DOI: 10.1128/aem.00810-12] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Palsa peats are characterized by elevated, circular frost heaves (peat soil on top of a permanently frozen ice lens) and are strong to moderate sources or even temporary sinks for the greenhouse gas nitrous oxide (N(2)O). Palsa peats are predicted to react sensitively to global warming. The acidic palsa peat Skalluvaara (approximate pH 4.4) is located in the discontinuous permafrost zone in northwestern Finnish Lapland. In situ N(2)O fluxes were spatially variable, ranging from 0.01 to -0.02 μmol of N(2)O m(-2) h(-1). Fertilization with nitrate stimulated in situ N(2)O emissions and N(2)O production in anoxic microcosms without apparent delay. N(2)O was subsequently consumed in microcosms. Maximal reaction velocities (v(max)) of nitrate-dependent denitrification approximated 3 and 1 nmol of N(2)O per h per gram (dry weight [g(DW)]) in soil from 0 to 20 cm and below 20 cm of depth, respectively. v(max) values of nitrite-dependent denitrification were 2- to 5-fold higher than the v(max) nitrate-dependent denitrification, and v(max) of N(2)O consumption was 1- to 6-fold higher than that of nitrite-dependent denitrification, highlighting a high N(2)O consumption potential. Up to 12 species-level operational taxonomic units (OTUs) of narG, nirK and nirS, and nosZ were retrieved. Detected OTUs suggested the presence of diverse uncultured soil denitrifiers and dissimilatory nitrate reducers, hitherto undetected species, as well as Actino-, Alpha-, and Betaproteobacteria. Copy numbers of nirS always outnumbered those of nirK by 2 orders of magnitude. Copy numbers of nirS tended to be higher, while copy numbers of narG and nosZ tended to be lower in 0- to 20-cm soil than in soil below 20 cm. The collective data suggest that (i) the source and sink functions of palsa peat soils for N(2)O are associated with denitrification, (ii) actinobacterial nitrate reducers and nirS-type and nosZ-harboring proteobacterial denitrifiers are important players, and (iii) acidic soils like palsa peats represent reservoirs of diverse acid-tolerant denitrifiers associated with N(2)O fluxes.
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Kolb S, Horn MA. Microbial CH(4) and N(2)O Consumption in Acidic Wetlands. Front Microbiol 2012; 3:78. [PMID: 22403579 PMCID: PMC3291872 DOI: 10.3389/fmicb.2012.00078] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 02/15/2012] [Indexed: 01/21/2023] Open
Abstract
Acidic wetlands are global sources of the atmospheric greenhouse gases methane (CH(4)), and nitrous oxide (N(2)O). Consumption of both atmospheric gases has been observed in various acidic wetlands, but information on the microbial mechanisms underlying these phenomena is scarce. A substantial amount of CH(4) is consumed in sub soil by aerobic methanotrophs at anoxic-oxic interfaces (e.g., tissues of Sphagnum mosses, rhizosphere of vascular plant roots). Methylocystis-related species are likely candidates that are involved in the consumption of atmospheric CH(4) in acidic wetlands. Oxygen availability regulates the activity of methanotrophs of acidic wetlands. Other parameters impacting on the methanotroph-mediated CH(4) consumption have not been systematically evaluated. N(2)O is produced and consumed by microbial denitrification, thus rendering acidic wetlands as temporary sources or sinks for N(2)O. Denitrifier communities in such ecosystems are diverse, and largely uncultured and/or new, and environmental factors that control their consumption activity are unresolved. Analyses of the composition of N(2)O reductase genes in acidic wetlands suggest that acid-tolerant Proteobacteria have the potential to mediate N(2)O consumption in such soils. Thus, the fragmented current state of knowledge raises open questions concerning methanotrophs and denitrifiers that consume atmospheric CH(4) and N(2)O in acidic wetlands.
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Affiliation(s)
- Steffen Kolb
- Department of Ecological Microbiology, University of BayreuthBayreuth, Germany
| | - Marcus A. Horn
- Department of Ecological Microbiology, University of BayreuthBayreuth, Germany
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Contrasting denitrifier communities relate to contrasting N2O emission patterns from acidic peat soils in arctic tundra. ISME JOURNAL 2011; 6:1058-77. [PMID: 22134649 DOI: 10.1038/ismej.2011.172] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cryoturbated peat circles (that is, bare surface soil mixed by frost action; pH 3-4) in the Russian discontinuous permafrost tundra are nitrate-rich 'hotspots' of nitrous oxide (N(2)O) emissions in arctic ecosystems, whereas adjacent unturbated peat areas are not. N(2)O was produced and subsequently consumed at pH 4 in unsupplemented anoxic microcosms with cryoturbated but not in those with unturbated peat soil. Nitrate, nitrite and acetylene stimulated net N(2)O production of both soils in anoxic microcosms, indicating denitrification as the source of N(2)O. Up to 500 and 10 μM nitrate stimulated denitrification in cryoturbated and unturbated peat soils, respectively. Apparent maximal reaction velocities of nitrite-dependent denitrification were 28 and 18 nmol N(2)O g(DW)(-1) h(-1), for cryoturbated and unturbated peat soils, respectively. Barcoded amplicon pyrosequencing of narG, nirK/nirS and nosZ (encoding nitrate, nitrite and N(2)O reductases, respectively) yielded ≈49 000 quality-filtered sequences with an average sequence length of 444 bp. Up to 19 species-level operational taxonomic units were detected per soil and gene, many of which were distantly related to cultured denitrifiers or environmental sequences. Denitrification-associated gene diversity in cryoturbated and in unturbated peat soils differed. Quantitative PCR (inhibition-corrected per DNA extract) revealed higher copy numbers of narG in cryoturbated than in unturbated peat soil. Copy numbers of nirS were up to 1000 × higher than those of nirK in both soils, and nirS nirK(-1) copy number ratios in cryoturbated and unturbated peat soils differed. The collective data indicate that the contrasting N(2)O emission patterns of cryoturbated and unturbated peat soils are associated with contrasting denitrifier communities.
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Braker G, Dörsch P, Bakken LR. Genetic characterization of denitrifier communities with contrasting intrinsic functional traits. FEMS Microbiol Ecol 2011; 79:542-54. [PMID: 22092293 DOI: 10.1111/j.1574-6941.2011.01237.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 10/04/2011] [Accepted: 10/24/2011] [Indexed: 11/28/2022] Open
Abstract
Microorganisms capable of denitrification are polyphyletic and exhibit distinct denitrification regulatory phenotypes (DRP), and thus, denitrification in soils could be controlled by community composition. In a companion study (Dörsch et al., 2012) and preceding work, ex situ denitrification assays of three organic soils demonstrated profoundly different functional traits including N(2) O/N(2) ratios. Here, we explored the composition of the underlying denitrifier communities by analyzing the abundance and structure of denitrification genes (nirK, nirS, and nosZ). The relative abundance of nosZ (vs. nirK + nirS) was similar for all communities, and hence, the low N(2) O reductase activity in one of the soils was not because of the lack of organisms with this gene. Similarity in community composition between the soils was generally low for nirK and nirS, but not for nosZ. The community with the most robust denitrification (consistently low N(2) O/N(2) ) had the highest diversity/richness of nosZ and nirK, but not of nirS. Contrary results found for a second soil agreed with impaired denitrification (low overall denitrification activity, high N(2) O/N(2) ). In conclusion, differences in community composition and in the absolute abundance of denitrification genes clearly reflected the functional differences observed in laboratory studies and may shed light on differences in in situ N(2) O emission of the soils.
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Affiliation(s)
- Gesche Braker
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
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Maeda K, Hanajima D, Toyoda S, Yoshida N, Morioka R, Osada T. Microbiology of nitrogen cycle in animal manure compost. Microb Biotechnol 2011; 4:700-9. [PMID: 21375720 PMCID: PMC3815407 DOI: 10.1111/j.1751-7915.2010.00236.x] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Accepted: 10/17/2010] [Indexed: 11/29/2022] Open
Abstract
Composting is the major technology in the treatment of animal manure and is a source of nitrous oxide, a greenhouse gas. Although the microbiological processes of both nitrification and denitrification are involved in composting, the key players in these pathways have not been well identified. Recent molecular microbiological methodologies have revealed the presence of dominant Bacillus species in the degradation of organic material or betaproteobacterial ammonia-oxidizing bacteria on nitrification on the surface, and have also revealed the mechanism of nitrous oxide emission in this complicated process to some extent. Some bacteria, archaea or fungi still would be considered potential key players, and the contribution of some pathways, such as nitrifier denitrification or heterotrophic nitrification, might be involved in composting. This review article discusses these potential microbial players in nitrification-denitrification within the composting pile and highlights the relevant unknowns through recent activities that focus on the nitrogen cycle within the animal manure composting process.
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Affiliation(s)
- Koki Maeda
- Hokkaido Research Subteam for Waste Recycling System, National Agricultural Research Center for Hokkaido Region, National Agricultural and Food Research Organization, 1 Hitsujigaoka, Sapporo 062-8555, Japan.
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Mao Y, Yannarell AC, Mackie RI. Changes in N-transforming archaea and bacteria in soil during the establishment of bioenergy crops. PLoS One 2011; 6:e24750. [PMID: 21935454 PMCID: PMC3173469 DOI: 10.1371/journal.pone.0024750] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 08/16/2011] [Indexed: 11/18/2022] Open
Abstract
Widespread adaptation of biomass production for bioenergy may influence important biogeochemical functions in the landscape, which are mainly carried out by soil microbes. Here we explore the impact of four potential bioenergy feedstock crops (maize, switchgrass, Miscanthus X giganteus, and mixed tallgrass prairie) on nitrogen cycling microorganisms in the soil by monitoring the changes in the quantity (real-time PCR) and diversity (barcoded pyrosequencing) of key functional genes (nifH, bacterial/archaeal amoA and nosZ) and 16S rRNA genes over two years after bioenergy crop establishment. The quantities of these N-cycling genes were relatively stable in all four crops, except maize (the only fertilized crop), in which the population size of AOB doubled in less than 3 months. The nitrification rate was significantly correlated with the quantity of ammonia-oxidizing archaea (AOA) not bacteria (AOB), indicating that archaea were the major ammonia oxidizers. Deep sequencing revealed high diversity of nifH, archaeal amoA, bacterial amoA, nosZ and 16S rRNA genes, with 229, 309, 330, 331 and 8989 OTUs observed, respectively. Rarefaction analysis revealed the diversity of archaeal amoA in maize markedly decreased in the second year. Ordination analysis of T-RFLP and pyrosequencing results showed that the N-transforming microbial community structures in the soil under these crops gradually differentiated. Thus far, our two-year study has shown that specific N-transforming microbial communities develop in the soil in response to planting different bioenergy crops, and each functional group responded in a different way. Our results also suggest that cultivation of maize with N-fertilization increases the abundance of AOB and denitrifiers, reduces the diversity of AOA, and results in significant changes in the structure of denitrification community.
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Affiliation(s)
- Yuejian Mao
- Energy Biosciences Institute, University of Illinois, Urbana, Illinois, United States of America
- Institute for Genomic Biology, University of Illinois, Urbana, Illinois, United States of America
| | - Anthony C. Yannarell
- Energy Biosciences Institute, University of Illinois, Urbana, Illinois, United States of America
- Institute for Genomic Biology, University of Illinois, Urbana, Illinois, United States of America
- Department of Natural Resources and Environmental Sciences, University of Illinois, Urbana, Illinois, United States of America
| | - Roderick I. Mackie
- Energy Biosciences Institute, University of Illinois, Urbana, Illinois, United States of America
- Institute for Genomic Biology, University of Illinois, Urbana, Illinois, United States of America
- Department of Animal Sciences, University of Illinois, Urbana, Illinois, United States of America
- * E-mail:
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Microorganisms with novel dissimilatory (bi)sulfite reductase genes are widespread and part of the core microbiota in low-sulfate peatlands. Appl Environ Microbiol 2010; 77:1231-42. [PMID: 21169452 DOI: 10.1128/aem.01352-10] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Peatlands of the Lehstenbach catchment (Germany) house as-yet-unidentified microorganisms with phylogenetically novel variants of the dissimilatory (bi)sulfite reductase genes dsrAB. These genes are characteristic of microorganisms that reduce sulfate, sulfite, or some organosulfonates for energy conservation but can also be present in anaerobic syntrophs. However, nothing is currently known regarding the abundance, community dynamics, and biogeography of these dsrAB-carrying microorganisms in peatlands. To tackle these issues, soils from a Lehstenbach catchment site (Schlöppnerbrunnen II fen) from different depths were sampled at three time points over a 6-year period to analyze the diversity and distribution of dsrAB-containing microorganisms by a newly developed functional gene microarray and quantitative PCR assays. Members of novel, uncultivated dsrAB lineages (approximately representing species-level groups) (i) dominated a temporally stable but spatially structured dsrAB community and (ii) represented "core" members (up to 1% to 1.7% relative abundance) of the autochthonous microbial community in this fen. In addition, denaturing gradient gel electrophoresis (DGGE)- and clone library-based comparisons of the dsrAB diversity in soils from a wet meadow, three bogs, and five fens of various geographic locations (distance of ∼1 to 400 km) identified that one Syntrophobacter-related and nine novel dsrAB lineages are widespread in low-sulfate peatlands. Signatures of biogeography in dsrB-based DGGE data were not correlated with geographic distance but could be explained largely by soil pH and wetland type, implying that the distribution of dsrAB-carrying microorganisms in wetlands on the scale of a few hundred kilometers is not limited by dispersal but determined by local environmental conditions.
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