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Melcher M, Hodgskiss LH, Mardini MA, Schleper C, Rittmann SKMR. Analysis of biomass productivity and physiology of Nitrososphaera viennensis grown in continuous culture. Front Microbiol 2023; 14:1076342. [PMID: 36876066 PMCID: PMC9978112 DOI: 10.3389/fmicb.2023.1076342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 01/17/2023] [Indexed: 02/18/2023] Open
Abstract
Microbial ammonia oxidation is the first and usually rate limiting step in nitrification and is therefore an important step in the global nitrogen cycle. Ammonia-oxidizing archaea (AOA) play an important role in nitrification. Here, we report a comprehensive analysis of biomass productivity and the physiological response of Nitrososphaera viennensis to different ammonium and carbon dioxide (CO2) concentrations aiming to understand the interplay between ammonia oxidation and CO2 fixation of N. viennensis. The experiments were performed in closed batch in serum bottles as well as in batch, fed-batch, and continuous culture in bioreactors. A reduced specific growth rate (μ) of N. viennensis was observed in batch systems in bioreactors. By increasing CO2 gassing μ could be increased to rates comparable to that of closed batch systems. Furthermore, at a high dilution rate (D) in continuous culture (≥ 0.7 of μmax) the biomass to ammonium yield (Y(X/NH3)) increased up to 81.7% compared to batch cultures. In continuous culture, biofilm formation at higher D prevented the determination of D crit. Due to changes in Y(X/NH3) and due to biofilm, nitrite concentration becomes an unreliable proxy for the cell number in continuous cultures at D towards μmax. Furthermore, the obscure nature of the archaeal ammonia oxidation prevents an interpretation in the context of Monod kinetics and thus the determination of K S. Our findings indicate that the physiological response of N. viennensis might be regulated with different enzymatic make-ups, according to the ammonium catalysis rate. We reveal novel insights into the physiology of N. viennensis that are important for biomass production and the biomass yield of AOA. Moreover, our study has implications to the field of archaea biology and microbial ecology by showing that bioprocess technology and quantitative analysis can be applied to decipher environmental factors affecting the physiology and productivity of AOA.
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Affiliation(s)
- Michael Melcher
- Archaea Biology and Ecogenomics Division, Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria
| | - Logan H Hodgskiss
- Archaea Biology and Ecogenomics Division, Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria
| | - Mohammad Anas Mardini
- Archaea Biology and Ecogenomics Division, Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria
| | - Christa Schleper
- Archaea Biology and Ecogenomics Division, Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria
| | - Simon K-M R Rittmann
- Archaea Biology and Ecogenomics Division, Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria.,Arkeon GmbH, Tulln a.d. Donau, Austria.,Archaea Physiology & Biotechnology Group, Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria
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2
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Mefferd CC, Zhou E, Seymour CO, Bernardo NA, Srivastava S, Bengtson AJ, Jiao JY, Dong H, Li WJ, Hedlund BP. Incomplete denitrification phenotypes in diverse Thermus species from diverse geothermal spring sediments and adjacent soils in southwest China. Extremophiles 2022; 26:23. [PMID: 35802188 PMCID: PMC9270275 DOI: 10.1007/s00792-022-01272-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 06/06/2022] [Indexed: 01/22/2023]
Abstract
A few members of the bacterial genus Thermus have been shown to be incomplete denitrifiers, terminating with nitrite (NO2-) or nitrous oxide (N2O). However, the denitrification abilities of the genus as a whole remain poorly characterized. Here, we describe diverse denitrification phenotypes and genotypes of a collection of 24 strains representing ten species, all isolated from a variety of geothermal systems in China. Confirmed terminal products of nitrate reduction were nitrite or N2O, while nitric oxide (NO) was inferred as the terminal product in some strains. Most strains produced N2O; complete denitrification was not observed. Denitrification phenotypes were largely consistent with the presence of denitrification genes, and strains of the same species often had the same denitrification phenotypes and largely syntenous denitrification gene clusters. Genes for nirS and nirK coexisted in three Thermus brockianus and three Thermus oshimai genomes, which is a unique hallmark of some denitrifying Thermus strains and may be ecologically important. These results show that incomplete denitrification phenotypes are prominent, but variable, within and between Thermus species. The incomplete denitrification phenotypes described here suggest Thermus species may play important roles in consortial denitrification in high-temperature terrestrial biotopes where sufficient supply of oxidized inorganic nitrogen exists.
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Affiliation(s)
| | - Enmin Zhou
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, USA
- School of Earth Sciences, Yunnan University, Kunming, People's Republic of China
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Cale O Seymour
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, USA
| | - Noel A Bernardo
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, USA
| | - Shreya Srivastava
- Department of Geology and Environmental Earth Science, Miami University, Oxford, OH, USA
| | - Amanda J Bengtson
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, USA
- SWCA Environmental Consultants, Las Vegas, NV, USA
| | - Jian-Yu Jiao
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Hailiang Dong
- Department of Geology and Environmental Earth Science, Miami University, Oxford, OH, USA
- State Key Laboratory of Biogeology and Environmental Geology and Institute of Earth Sciences, China University of Geosciences, Beijing, People's Republic of China
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China.
| | - Brian P Hedlund
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, USA.
- Nevada Institute for Personalized Medicine, University of Nevada, Las Vegas, Las Vegas, NV, USA.
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3
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Soldatova E, Dong Y, Li J, Liu Y, Zan J, Boeckx P, Sun Z. Nitrogen transformation and pathways in the shallow groundwater-soil system within agricultural landscapes. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2021; 43:441-459. [PMID: 33000346 DOI: 10.1007/s10653-020-00733-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 09/21/2020] [Indexed: 06/11/2023]
Abstract
The present study considers the behavior of nitrogen compounds in the shallow groundwater-soil system as necessary for the functioning of the nitrogen cycle within agricultural landscapes and one of the first steps of the formation of groundwater chemical composition. Data were collected in 2011-2018 within the Poyang Lake area (Jiangxi Province, China), where agricultural landscapes prevail. The soil and groundwater samples were taken in different periods of an agricultural season at the beginning of the agricultural season (spring) and after harvesting (autumn). The combined geochemical data on the chemical and microbiological composition of the soils and shallow groundwater and isotopic data on dissolved nitrate allowed researchers to resolve that nitrogen enters the system in the form of organic compounds, particularly, due to the soil fertilization at the beginning of the agricultural season. Organic nitrogen compounds transform into nitrate under the influence of nitrifiers in the soil before getting the shallow aquifer, where the occurrence of denitrification is suggested. Within the Ganjiang and Xiushui interfluve, reducing conditions, together with the formation of clay minerals from the aqueous solution, may serve a geochemical barrier for the accumulation of nitrogen compounds preventing the transformation of ammonium to nitrate and providing its sorption. It also should be noted that bacterial diversity in the shallow groundwater has a strong relation with the amount of nitrate in the system, whereas in the soil, it is connected with sampling depth.
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Affiliation(s)
- Evgeniya Soldatova
- Laboratory of Modeling Hydrogeochemical and Hydrothermal Processes, Vernadsky Institute of Geochemistry and Analytical Chemistry of Russian Academy of Sciences, 119991, Moscow, Russia.
| | - Yihui Dong
- State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang, 330013, China
- School of Water Resources and Environmental Engineering, East China University of Technology, Nanchang, 330013, China
| | - Jiale Li
- State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang, 330013, China
- School of Water Resources and Environmental Engineering, East China University of Technology, Nanchang, 330013, China
| | - Yajie Liu
- School of Water Resources and Environmental Engineering, East China University of Technology, Nanchang, 330013, China
| | - Jinjing Zan
- School of Water Resources and Environmental Engineering, East China University of Technology, Nanchang, 330013, China
| | - Pascal Boeckx
- Isotope Bioscience Laboratory (ISOFYS), Ghent University, 9000, Ghent, Belgium
| | - Zhanxue Sun
- State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang, 330013, China
- School of Water Resources and Environmental Engineering, East China University of Technology, Nanchang, 330013, China
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4
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Martin-Pozas T, Sanchez-Moral S, Cuezva S, Jurado V, Saiz-Jimenez C, Perez-Lopez R, Carrey R, Otero N, Giesemann A, Well R, Calaforra JM, Fernandez-Cortes A. Biologically mediated release of endogenous N 2O and NO 2 gases in a hydrothermal, hypoxic subterranean environment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 747:141218. [PMID: 32777502 DOI: 10.1016/j.scitotenv.2020.141218] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/17/2020] [Accepted: 07/22/2020] [Indexed: 06/11/2023]
Abstract
The migration of geogenic gases in continental areas with geothermal activity and active faults is an important process releasing greenhouse gases (GHG) to the lower troposphere. In this respect, caves in hypogenic environments are natural laboratories to study the compositional evolution of deep-endogenous fluids through the Critical Zone. Vapour Cave (Alhama, Murcia, Spain) is a hypogenic cave formed by the upwelling of hydrothermal CO2-rich fluids. Anomalous concentrations of N2O and NO2 were registered in the cave's subterranean atmosphere, averaging ten and five times the typical atmospheric backgrounds, respectively. We characterised the thermal conditions, gaseous compositions, sediments, and microbial communities at different depths in the cave. We did so to understand the relation between N-cycling microbial groups and the production and transformation of nitrogenous gases, as well as their coupled evolution with CO2 and CH4 during their migration through the Critical Zone to the lower troposphere. Our results showed an evident vertical stratification of selected microbial groups (Archaea and Bacteria) depending on the environmental parameters, including O2, temperature, and GHG concentration. Both the N2O isotope ratios and the predicted ecological functions of bacterial and archaeal communities suggest that N2O and NO2 emissions mainly depend on the nitrification by ammonia-oxidising microorganisms. Denitrification and abiotic reactions of the reactive intermediates NH2OH, NO, and NO2- are also plausible according to the results of the phylogenetic analyses of the microbial communities. Nitrite-dependent anaerobic methane oxidation by denitrifying methanotrophs of the NC10 phylum was also identified as a post-genetic process during migration of this gas to the surface. To the best of our knowledge, our report provides, for the first time, evidence of a niche densely populated by Micrarchaeia, which represents more than 50% of the total archaeal abundance. This raises many questions on the metabolic behaviour of this and other archaeal phyla.
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Affiliation(s)
- Tamara Martin-Pozas
- Department of Geology, National Museum of Natural Sciences (MNCN-CSIC), 28006 Madrid, Spain.
| | - Sergio Sanchez-Moral
- Department of Geology, National Museum of Natural Sciences (MNCN-CSIC), 28006 Madrid, Spain.
| | - Soledad Cuezva
- Plants and Ecosystems, Department of Biology, University of Antwerp, 2610 Wilrijk, Belgium.
| | - Valme Jurado
- Department of Agrochemistry, Environmental Microbiology and Soil Conservation, Institute of Natural Resources and Agricultural Biology (IRNAS-CSIC), 41012 Seville, Spain.
| | - Cesareo Saiz-Jimenez
- Department of Agrochemistry, Environmental Microbiology and Soil Conservation, Institute of Natural Resources and Agricultural Biology (IRNAS-CSIC), 41012 Seville, Spain.
| | - Raul Perez-Lopez
- Geological Hazard Division, Geological Survey of Spain (IGME), 28003 Madrid, Spain.
| | - Raul Carrey
- Grup MAiMA, SGR Mineralogia Aplicada, Geoquímica i Geomicrobiologia, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), 08028 Barcelona, Spain; Institut de Recerca de l'Aigua (IdRA), UB, 08001 Barcelona, Spain.
| | - Neus Otero
- Grup MAiMA, SGR Mineralogia Aplicada, Geoquímica i Geomicrobiologia, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), 08028 Barcelona, Spain; Institut de Recerca de l'Aigua (IdRA), UB, 08001 Barcelona, Spain.
| | - Anette Giesemann
- Thünen Institute of Climate-Smart Agriculture, Federal Research Institute for Rural Areas, Forestry and Fisheries, 38116 Braunschweig, Germany.
| | - Reinhard Well
- Thünen Institute of Climate-Smart Agriculture, Federal Research Institute for Rural Areas, Forestry and Fisheries, 38116 Braunschweig, Germany.
| | - Jose M Calaforra
- Department of Biology and Geology, University of Almeria, 04120 Almeria, Spain.
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5
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Martínez-Espinosa RM. Microorganisms and Their Metabolic Capabilities in the Context of the Biogeochemical Nitrogen Cycle at Extreme Environments. Int J Mol Sci 2020; 21:ijms21124228. [PMID: 32545812 PMCID: PMC7349289 DOI: 10.3390/ijms21124228] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 06/12/2020] [Indexed: 12/23/2022] Open
Abstract
Extreme microorganisms (extremophile) are organisms that inhabit environments characterized by inhospitable parameters for most live beings (extreme temperatures and pH values, high or low ionic strength, pressure, or scarcity of nutrients). To grow optimally under these conditions, extremophiles have evolved molecular adaptations affecting their physiology, metabolism, cell signaling, etc. Due to their peculiarities in terms of physiology and metabolism, they have become good models for (i) understanding the limits of life on Earth, (ii) exploring the possible existence of extraterrestrial life (Astrobiology), or (iii) to look for potential applications in biotechnology. Recent research has revealed that extremophilic microbes play key roles in all biogeochemical cycles on Earth. Nitrogen cycle (N-cycle) is one of the most important biogeochemical cycles in nature; thanks to it, nitrogen is converted into multiple chemical forms, which circulate among atmospheric, terrestrial and aquatic ecosystems. This review summarizes recent knowledge on the role of extreme microorganisms in the N-cycle in extremophilic ecosystems, with special emphasis on members of the Archaea domain. Potential implications of these microbes in global warming and nitrogen balance, as well as their biotechnological applications are also discussed.
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Affiliation(s)
- Rosa María Martínez-Espinosa
- Biochemistry and Molecular Biology Division, Agrochemistry and Biochemistry Department, Faculty of Sciences, University of Alicante, Ap. 99, E-03080 Alicante, Spain; ; Tel.: +34-965903400 (ext. 1258)
- Multidisciplinary Institute for Environmental Studies “Ramón Margalef”, University of Alicante, Ap. 99, E-03080 Alicante, Spain
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6
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Sorensen JW, Dunivin TK, Tobin TC, Shade A. Ecological selection for small microbial genomes along a temperate-to-thermal soil gradient. Nat Microbiol 2018; 4:55-61. [PMID: 30397342 DOI: 10.1038/s41564-018-0276-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 09/27/2018] [Indexed: 01/14/2023]
Abstract
Small bacterial and archaeal genomes provide insights into the minimal requirements for life1 and are phylogenetically widespread2. However, the precise environmental pressures that constrain genome size in free-living microorganisms are unknown. A study including isolates has shown that thermophiles and other bacteria with high optimum growth temperatures often have small genomes3. It is unclear whether this relationship extends generally to microorganisms in nature4,5 and more specifically to microorganisms that inhabit complex and highly variable environments, such as soils3,6,7. To understand the genomic traits of thermally adapted microorganisms, here we investigated metagenomes from a 45 °C gradient of temperate-to-thermal soils that lie over the ongoing Centralia, Pennsylvania (USA) coal-seam fire. We found that hot soils harboured distinct communities with small genomes and small cell sizes relative to those in ambient soils. Hot soils notably lacked genes that encode known two-component regulatory systems, and antimicrobial production and resistance genes. Our results provide field evidence for the inverse relationship between microbial genome size and temperature in a diverse, free-living community over a wide range of temperatures that support microbial life.
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Affiliation(s)
- Jackson W Sorensen
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - Taylor K Dunivin
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA.,Environmental and Integrative Toxicological Sciences, Michigan State University, East Lansing, MI, USA
| | - Tammy C Tobin
- Department of Biology, Susquehanna University, Selinsgrove, PA, USA
| | - Ashley Shade
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA. .,Department of Plant, Soil and Microbial Sciences, Program in Ecology, Evolutionary Biology and Behavior and the Plant Resilience Institute, Michigan State University, East Lansing, MI, USA.
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7
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Alcamán-Arias ME, Pedrós-Alió C, Tamames J, Fernández C, Pérez-Pantoja D, Vásquez M, Díez B. Diurnal Changes in Active Carbon and Nitrogen Pathways Along the Temperature Gradient in Porcelana Hot Spring Microbial Mat. Front Microbiol 2018; 9:2353. [PMID: 30333812 PMCID: PMC6176055 DOI: 10.3389/fmicb.2018.02353] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 09/13/2018] [Indexed: 01/14/2023] Open
Abstract
Composition, carbon and nitrogen uptake, and gene transcription of microbial mat communities in Porcelana neutral hot spring (Northern Chilean Patagonia) were analyzed using metagenomics, metatranscriptomics and isotopically labeled carbon (H13CO3) and nitrogen (15NH4Cl and K15NO3) assimilation rates. The microbial mat community included 31 phyla, of which only Cyanobacteria and Chloroflexi were dominant. At 58°C both phyla co-occurred, with similar contributions in relative abundances in metagenomes and total transcriptional activity. At 66°C, filamentous anoxygenic phototrophic Chloroflexi were >90% responsible for the total transcriptional activity recovered, while Cyanobacteria contributed most metagenomics and metatranscriptomics reads at 48°C. According to such reads, phototrophy was carried out both through oxygenic photosynthesis by Cyanobacteria (mostly Mastigocladus) and anoxygenic phototrophy due mainly to Chloroflexi. Inorganic carbon assimilation through the Calvin-Benson cycle was almost exclusively due to Mastigocladus, which was the main primary producer at lower temperatures. Two other CO2 fixation pathways were active at certain times and temperatures as indicated by transcripts: 3-hydroxypropionate (3-HP) bi-cycle due to Chloroflexi and 3-hydroxypropionate-4-hydroxybutyrate (HH) cycle carried out by Thaumarchaeota. The active transcription of the genes involved in these C-fixation pathways correlated with high in situ determined carbon fixation rates. In situ measurements of ammonia assimilation and nitrogen fixation (exclusively attributed to Cyanobacteria and mostly to Mastigocladus sp.) showed these were the most important nitrogen acquisition pathways at 58 and 48°C. At 66°C ammonia oxidation genes were actively transcribed (mostly due to Thaumarchaeota). Reads indicated that denitrification was present as a nitrogen sink at all temperatures and that dissimilatory nitrate reduction to ammonia (DNRA) contributed very little. The combination of metagenomic and metatranscriptomic analysis with in situ assimilation rates, allowed the reconstruction of day and night carbon and nitrogen assimilation pathways together with the contribution of keystone microorganisms in this natural hot spring microbial mat.
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Affiliation(s)
- María E. Alcamán-Arias
- Department of Oceanography, Universidad de Concepción, Concepción, Chile
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
- Center for Climate and Resilience Research, Universidad de Chile, Santiago, Chile
| | - Carlos Pedrós-Alió
- Programa de Biología de Sistemas, Centro Nacional de Biotecnología – Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Javier Tamames
- Programa de Biología de Sistemas, Centro Nacional de Biotecnología – Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Camila Fernández
- Department of Oceanography, Universidad de Concepción, Concepción, Chile
- Laboratoire d’Océanographie Microbienne, Observatoire Océanologique, Sorbonne Universités, Université Pierre-et-Marie-Curie, Centre National de la Recherche Scientifique, Banyuls-sur-Mer, France
- Fondap IDEAL, Universidad Austral de Chile, Valdivia, Chile
| | - Danilo Pérez-Pantoja
- Programa Institucional de Fomento a la Investigación, Desarrollo e Innovación, Universidad Tecnológica Metropolitana, Santiago, Chile
| | - Mónica Vásquez
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Beatriz Díez
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
- Center for Climate and Resilience Research, Universidad de Chile, Santiago, Chile
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8
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Zuo R, Jin S, Chen M, Guan X, Wang J, Zhai Y, Teng Y, Guo X. In-situ study of migration and transformation of nitrogen in groundwater based on continuous observations at a contaminated desert site. JOURNAL OF CONTAMINANT HYDROLOGY 2018; 211:39-48. [PMID: 29551242 DOI: 10.1016/j.jconhyd.2018.03.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 02/04/2018] [Accepted: 03/02/2018] [Indexed: 06/08/2023]
Abstract
The objective of this study was to explore the controlling factors on the migration and transformation of nitrogenous wastes in groundwater using long-term observations from a contaminated site on the southwestern edge of the Tengger Desert in northwestern China. Contamination was caused by wastewater discharge rich in ammonia. Two long-term groundwater monitoring wells (Wells 1# and 2#) were constructed, and 24 water samples were collected. Five key indicators were tested: ammonia, nitrate, nitrite, dissolved oxygen, and manganese. A numerical method was used to simulate the migration process and to determine the migration stage of the main pollutant plume in groundwater. The results showed that at Well 1# the nitrogenous waste migration process had essentially been completed, while at Well 2# ammonia levels were still rising and gradually transitioning to a stable stage. The differences for Well 1# and Well 2# were primarily caused by differences in groundwater flow. The change in ammonia concentration was mainly controlled by the migration of the pollution plume under nitrification in groundwater. The nitrification rate was likely affected by changes in dissolved oxygen and potentially manganese.
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Affiliation(s)
- Rui Zuo
- College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing 100875, China.
| | - Shuhe Jin
- College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing 100875, China
| | - Minhua Chen
- College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing 100875, China
| | - Xin Guan
- College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing 100875, China
| | - Jinsheng Wang
- College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing 100875, China
| | - Yuanzheng Zhai
- College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing 100875, China
| | - Yanguo Teng
- College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing 100875, China
| | - Xueru Guo
- College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing 100875, China
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9
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Molecular Mechanisms Contributing to the Growth and Physiology of an Extremophile Cultured with Dielectric Heating. Appl Environ Microbiol 2016; 82:6233-6246. [PMID: 27520819 DOI: 10.1128/aem.02020-16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 08/08/2016] [Indexed: 11/20/2022] Open
Abstract
The effect of microwave frequency electromagnetic fields on living microorganisms is an active and highly contested area of research. One of the major drawbacks to using mesophilic organisms to study microwave radiation effects is the unavoidable heating of the organism, which has limited the scale (<5 ml) and duration (<1 h) of experiments. However, the negative effects of heating a mesophile can be mitigated by employing thermophiles (organisms able to grow at temperatures of >60°C). This study identified changes in global gene expression profiles during the growth of Thermus scotoductus SA-01 at 65°C using dielectric (2.45 GHz, i.e., microwave) heating. RNA sequencing was performed on cultures at 8, 14, and 24 h after inoculation to determine the molecular mechanisms contributing to long-term cellular growth and survival under microwave heating conditions. Over the course of growth, genes associated with amino acid metabolism, carbohydrate metabolism, and defense mechanisms were upregulated; the number of repressed genes with unknown function increased; and at all time points, transposases were upregulated. Genes involved in cell wall biogenesis and elongation were also upregulated, consistent with the distinct elongated cell morphology observed after 24 h using microwave heating. Analysis of the global differential gene expression data enabled the identification of molecular processes specific to the response of T. scotoductus SA-01 to dielectric heating during growth. IMPORTANCE The residual heating of living organisms in the microwave region of the electromagnetic spectrum has complicated the identification of radiation-only effects using microorganisms for 50 years. A majority of the previous experiments used either mature cells or short exposure times with low-energy high-frequency radiation. Using global differential gene expression data, we identified molecular processes unique to dielectric heating using Thermus scotoductus SA-01 cultured over 30 h in a commercial microwave digestor. Genes associated with amino acid metabolism, carbohydrate metabolism, and defense mechanisms were upregulated; the number of repressed genes with unknown function increased; and at all time points, transposases were upregulated. These findings serve as a platform for future studies with mesophiles in order to better understand the response of microorganisms to microwave radiation.
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10
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Imhoff JF. New Dimensions in Microbial Ecology-Functional Genes in Studies to Unravel the Biodiversity and Role of Functional Microbial Groups in the Environment. Microorganisms 2016; 4:microorganisms4020019. [PMID: 27681913 PMCID: PMC5029485 DOI: 10.3390/microorganisms4020019] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 05/20/2016] [Accepted: 05/20/2016] [Indexed: 12/11/2022] Open
Abstract
During the past decades, tremendous advances have been made in the possibilities to study the diversity of microbial communities in the environment. The development of methods to study these communities on the basis of 16S rRNA gene sequences analysis was a first step into the molecular analysis of environmental communities and the study of biodiversity in natural habitats. A new dimension in this field was reached with the introduction of functional genes of ecological importance and the establishment of genetic tools to study the diversity of functional microbial groups and their responses to environmental factors. Functional gene approaches are excellent tools to study the diversity of a particular function and to demonstrate changes in the composition of prokaryote communities contributing to this function. The phylogeny of many functional genes largely correlates with that of the 16S rRNA gene, and microbial species may be identified on the basis of functional gene sequences. Functional genes are perfectly suited to link culture-based microbiological work with environmental molecular genetic studies. In this review, the development of functional gene studies in environmental microbiology is highlighted with examples of genes relevant for important ecophysiological functions. Examples are presented for bacterial photosynthesis and two types of anoxygenic phototrophic bacteria, with genes of the Fenna-Matthews-Olson-protein (fmoA) as target for the green sulfur bacteria and of two reaction center proteins (pufLM) for the phototrophic purple bacteria, with genes of adenosine-5'phosphosulfate (APS) reductase (aprA), sulfate thioesterase (soxB) and dissimilatory sulfite reductase (dsrAB) for sulfur oxidizing and sulfate reducing bacteria, with genes of ammonia monooxygenase (amoA) for nitrifying/ammonia-oxidizing bacteria, with genes of particulate nitrate reductase and nitrite reductases (narH/G, nirS, nirK) for denitrifying bacteria and with genes of methane monooxygenase (pmoA) for methane oxidizing bacteria.
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Affiliation(s)
- Johannes F Imhoff
- GEOMAR Helmholtz-Zentrum für Ozeanforschung, Düsternbrooker Weg 20, D-24105 Kiel, Germany.
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11
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Zhou EM, Murugapiran SK, Mefferd CC, Liu L, Xian WD, Yin YR, Ming H, Yu TT, Huntemann M, Clum A, Pillay M, Palaniappan K, Varghese N, Mikhailova N, Stamatis D, Reddy TBK, Ngan CY, Daum C, Shapiro N, Markowitz V, Ivanova N, Spunde A, Kyrpides N, Woyke T, Li WJ, Hedlund BP. High-quality draft genome sequence of the Thermus amyloliquefaciens type strain YIM 77409(T) with an incomplete denitrification pathway. Stand Genomic Sci 2016; 11:20. [PMID: 26925197 PMCID: PMC4769583 DOI: 10.1186/s40793-016-0140-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 12/10/2015] [Indexed: 11/25/2022] Open
Abstract
Thermus amyloliquefaciens type strain YIM 77409(T) is a thermophilic, Gram-negative, non-motile and rod-shaped bacterium isolated from Niujie Hot Spring in Eryuan County, Yunnan Province, southwest China. In the present study we describe the features of strain YIM 77409(T) together with its genome sequence and annotation. The genome is 2,160,855 bp long and consists of 6 scaffolds with 67.4 % average GC content. A total of 2,313 genes were predicted, comprising 2,257 protein-coding and 56 RNA genes. The genome is predicted to encode a complete glycolysis, pentose phosphate pathway, and tricarboxylic acid cycle. Additionally, a large number of transporters and enzymes for heterotrophy highlight the broad heterotrophic lifestyle of this organism. A denitrification gene cluster included genes predicted to encode enzymes for the sequential reduction of nitrate to nitrous oxide, consistent with the incomplete denitrification phenotype of this strain.
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Affiliation(s)
- En-Min Zhou
- />Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091 People’s Republic of China
- />School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV USA
| | | | | | - Lan Liu
- />State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, College of Ecology and Evolution, Sun Yat-Sen University, Guangzhou, 510275 People’s Republic of China
| | - Wen-Dong Xian
- />Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091 People’s Republic of China
| | - Yi-Rui Yin
- />Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091 People’s Republic of China
| | - Hong Ming
- />Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091 People’s Republic of China
| | - Tian-Tian Yu
- />Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091 People’s Republic of China
| | - Marcel Huntemann
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Alicia Clum
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Manoj Pillay
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | | | - Neha Varghese
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | | | | | - T. B. K. Reddy
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Chew Yee Ngan
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Chris Daum
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Nicole Shapiro
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Victor Markowitz
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Natalia Ivanova
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Alexander Spunde
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Nikos Kyrpides
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Tanja Woyke
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Wen-Jun Li
- />Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091 People’s Republic of China
- />State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, College of Ecology and Evolution, Sun Yat-Sen University, Guangzhou, 510275 People’s Republic of China
| | - Brian P. Hedlund
- />School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV USA
- />Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV USA
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12
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Single-Cell-Genomics-Facilitated Read Binning of Candidate Phylum EM19 Genomes from Geothermal Spring Metagenomes. Appl Environ Microbiol 2015; 82:992-1003. [PMID: 26637598 DOI: 10.1128/aem.03140-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 11/12/2015] [Indexed: 12/17/2022] Open
Abstract
The vast majority of microbial life remains uncatalogued due to the inability to cultivate these organisms in the laboratory. This "microbial dark matter" represents a substantial portion of the tree of life and of the populations that contribute to chemical cycling in many ecosystems. In this work, we leveraged an existing single-cell genomic data set representing the candidate bacterial phylum "Calescamantes" (EM19) to calibrate machine learning algorithms and define metagenomic bins directly from pyrosequencing reads derived from Great Boiling Spring in the U.S. Great Basin. Compared to other assembly-based methods, taxonomic binning with a read-based machine learning approach yielded final assemblies with the highest predicted genome completeness of any method tested. Read-first binning subsequently was used to extract Calescamantes bins from all metagenomes with abundant Calescamantes populations, including metagenomes from Octopus Spring and Bison Pool in Yellowstone National Park and Gongxiaoshe Spring in Yunnan Province, China. Metabolic reconstruction suggests that Calescamantes are heterotrophic, facultative anaerobes, which can utilize oxidized nitrogen sources as terminal electron acceptors for respiration in the absence of oxygen and use proteins as their primary carbon source. Despite their phylogenetic divergence, the geographically separate Calescamantes populations were highly similar in their predicted metabolic capabilities and core gene content, respiring O2, or oxidized nitrogen species for energy conservation in distant but chemically similar hot springs.
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13
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Hong JK, Cho JC. Environmental Variables Shaping the Ecological Niche of Thaumarchaeota in Soil: Direct and Indirect Causal Effects. PLoS One 2015; 10:e0133763. [PMID: 26241328 PMCID: PMC4524719 DOI: 10.1371/journal.pone.0133763] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 07/01/2015] [Indexed: 11/18/2022] Open
Abstract
To find environmental variables (EVs) shaping the ecological niche of the archaeal phylum Thaumarchaeota in terrestrial environments, we determined the abundance of Thaumarchaeota in various soil samples using real-time PCR targeting thaumarchaeotal 16S rRNA gene sequences. We employed our previously developed primer, THAUM-494, which had greater coverage for Thaumarchaeota and lower tolerance to nonthaumarchaeotal taxa than previous Thaumarchaeota-directed primers. The relative abundance estimates (RVs) of Thaumarchaeota (RTHAUM), Archaea (RARCH), and Bacteria (RBACT) were subjected to a series of statistical analyses. Redundancy analysis (RDA) showed a significant (p < 0.05) canonical relationship between RVs and EVs. Negative causal relationships between RTHAUM and nutrient level-related EVs were observed in an RDA biplot. These negative relationships were further confirmed by correlation and regression analyses. Total nitrogen content (TN) appeared to be the EV that affected RTHAUM most strongly, and total carbon content (TC), which reflected the content of organic matter (OM), appeared to be the EV that affected it least. However, in the path analysis, a path model indicated that TN might be a mediator EV that could be controlled directly by the OM. Additionally, another path model implied that water content (WC) might also indirectly affect RTHAUM by controlling ammonium nitrogen (NH4+-N) level through ammonification. Thus, although most directly affected by NH4+-N, RTHAUM could be ultimately determined by OM content, suggesting that Thaumarchaeota could prefer low-OM or low-WC conditions, because either of these EVs could subsequently result in low levels of NH4+-N in soil.
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Affiliation(s)
- Jin-Kyung Hong
- Institute of Environmental Sciences and Department of Environmental Sciences, Hankuk University of Foreign Studies, Yong-In, Korea
| | - Jae-Chang Cho
- Institute of Environmental Sciences and Department of Environmental Sciences, Hankuk University of Foreign Studies, Yong-In, Korea
- * E-mail:
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14
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Hedlund BP, Reysenbach AL, Huang L, Ong JC, Liu Z, Dodsworth JA, Ahmed R, Williams AJ, Briggs BR, Liu Y, Hou W, Dong H. Isolation of diverse members of the Aquificales from geothermal springs in Tengchong, China. Front Microbiol 2015; 6:157. [PMID: 25774153 PMCID: PMC4343020 DOI: 10.3389/fmicb.2015.00157] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 02/11/2015] [Indexed: 11/28/2022] Open
Abstract
The order Aquificales (phylum Aquificae) consists of thermophilic and hyperthermophilic bacteria that are prominent in many geothermal systems, including those in Tengchong, Yunnan Province, China. However, Aquificales have not previously been isolated from Tengchong. We isolated five strains of Aquificales from diverse springs (temperature 45.2–83.3°C and pH 2.6–9.1) in the Rehai Geothermal Field from sites in which Aquificales were abundant. Phylogenetic analysis showed that four of the strains belong to the genera Hydrogenobacter, Hydrogenobaculum, and Sulfurihydrogenibium, including strains distant enough to likely justify new species of Hydrogenobacter and Hydrogenobaculum. The additional strain may represent a new genus in the Hydrogenothermaceae. All strains were capable of aerobic respiration under microaerophilic conditions; however, they had variable capacity for chemolithotrophic oxidation of hydrogen and sulfur compounds and nitrate reduction.
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Affiliation(s)
- Brian P Hedlund
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA ; Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - Anna-Louise Reysenbach
- Biology Department and Center for Life in Extreme Environments, Portland State University Portland, OR, USA
| | - Liuquin Huang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences Beijing, China
| | - John C Ong
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - Zizhang Liu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences Beijing, China
| | - Jeremy A Dodsworth
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA ; Department of Biology, California State University San Bernardino San Bernardino, CA, USA
| | - Reham Ahmed
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - Amanda J Williams
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - Brandon R Briggs
- Department of Geology and Environmental Earth Science, Miami University, Oxford, OH, USA
| | - Yitai Liu
- Biology Department and Center for Life in Extreme Environments, Portland State University Portland, OR, USA
| | - Weiguo Hou
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences Beijing, China
| | - Hailiang Dong
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences Beijing, China ; Department of Geology and Environmental Earth Science, Miami University, Oxford, OH, USA
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15
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Affiliation(s)
- Luisa B. Maia
- REQUIMTE/CQFB, Departamento
de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - José J. G. Moura
- REQUIMTE/CQFB, Departamento
de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
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16
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Kallotenue papyrolyticum gen. nov., sp. nov., a cellulolytic and filamentous thermophile that represents a novel lineage (Kallotenuales ord. nov., Kallotenuaceae fam. nov.) within the class Chloroflexia. Int J Syst Evol Microbiol 2013; 63:4675-4682. [DOI: 10.1099/ijs.0.053348-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Several closely related, thermophilic and cellulolytic bacterial strains, designated JKG1T, JKG2, JKG3, JKG4 and JKG5, were isolated from a cellulolytic enrichment (corn stover) incubated in the water column of Great Boiling Spring, NV. Strain JKG1T had cells of diameter 0.7–0.9 µm and length ~2.0 µm that formed non-branched, multicellular filaments reaching >300 µm. Spores were not formed and dense liquid cultures were red. The temperature range for growth was 45–65 °C, with an optimum of 55 °C. The pH range for growth was pH 5.6–9.0, with an optimum of pH 7.5. JKG1T grew as an aerobic heterotroph, utilizing glucose, sucrose, xylose, arabinose, cellobiose, CM-cellulose, filter paper, microcrystalline cellulose, xylan, starch, Casamino acids, tryptone, peptone, yeast extract, acetate, citrate, lactate, pyruvate and glycerol as sole carbon sources, and was not observed to photosynthesize. The cells stained Gram-negative. Phylogenetic analysis using 16S rRNA gene sequences placed the new isolates in the class
Chloroflexia
, but distant from other cultivated members, with the highest sequence identity of 82.5 % to
Roseiflexus castenholzii
. The major quinone was menaquinone-9; no ubiquinones were detected. The major cellular fatty acids (>5 %) were C18 : 0, anteiso-C17 : 0, iso-C18 : 0, iso-C17 : 0, C16 : 0, iso-C16 : 0 and C17 : 0. The peptidoglycan amino acids were alanine, ornithine, glutamic acid, serine and asparagine. Whole-cell sugars included mannose, rhamnose, glucose, galactose, ribose, arabinose and xylose. Morphological, phylogenetic and chemotaxonomic results suggest that JKG1T is representative of a new lineage within the class
Chloroflexia
, which we propose to designate Kallotenue papyrolyticum gen. nov., sp. nov., Kallotenuaceae fam. nov., Kallotenuales ord. nov. The type strain of Kallotenue papyrolyticum gen. nov., sp. nov. is JKG1T ( = DSM 26889T = JCM 19132T).
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17
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Hedlund BP, Paraiso JJ, Williams AJ, Huang Q, Wei Y, Dijkstra P, Hungate BA, Dong H, Zhang CL. Wide distribution of autochthonous branched glycerol dialkyl glycerol tetraethers (bGDGTs) in U.S. Great Basin hot springs. Front Microbiol 2013; 4:222. [PMID: 23964271 PMCID: PMC3737515 DOI: 10.3389/fmicb.2013.00222] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 07/21/2013] [Indexed: 11/18/2022] Open
Abstract
Branched glycerol dialkyl glycerol tetraethers (bGDGTs) are membrane-spanning lipids that likely stabilize membranes of some bacteria. Although bGDGTs have been reported previously in certain geothermal environments, it has been suggested that they may derive from surrounding soils since bGDGTs are known to be produced by soil bacteria. To test the hypothesis that bGDGTs can be produced by thermophiles in geothermal environments, we examined the distribution and abundance of bGDGTs, along with extensive geochemical data, in 40 sediment and mat samples collected from geothermal systems in the U.S. Great Basin (temperature: 31–95°C; pH: 6.8–10.7). bGDGTs were found in 38 out of 40 samples at concentrations up to 824 ng/g sample dry mass and comprised up to 99.5% of total GDGTs (branched plus isoprenoidal). The wide distribution of bGDGTs in hot springs, strong correlation between core and polar lipid abundances, distinctness of bGDGT profiles compared to nearby soils, and higher concentration of bGDGTs in hot springs compared to nearby soils provided evidence of in situ production, particularly for the minimally methylated bGDGTs I, Ib, and Ic. Polar bGDGTs were found almost exclusively in samples ≤70°C and the absolute abundance of polar bGDGTs correlated negatively with properties of chemically reduced, high temperature spring sources (temperature, H2S/HS−) and positively with properties of oxygenated, low temperature sites (O2, NO−3). Two-way cluster analysis and nonmetric multidimensional scaling based on relative abundance of polar bGDGTs supported these relationships and showed a negative relationship between the degree of methylation and temperature, suggesting a higher abundance for minimally methylated bGDGTs at high temperature. This study presents evidence of the widespread production of bGDGTs in mats and sediments of natural geothermal springs in the U.S. Great Basin, especially in oxygenated, low-temperature sites (≤70°C).
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Affiliation(s)
- Brian P Hedlund
- School of Life Sciences, University of Nevada, Las Vegas Las Vegas, NV, USA
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18
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Schoenfeld TW, Murugapiran SK, Dodsworth JA, Floyd S, Lodes M, Mead DA, Hedlund BP. Lateral gene transfer of family A DNA polymerases between thermophilic viruses, aquificae, and apicomplexa. Mol Biol Evol 2013; 30:1653-64. [PMID: 23608703 DOI: 10.1093/molbev/mst078] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Bioinformatics and functional screens identified a group of Family A-type DNA Polymerase (polA) genes encoded by viruses inhabiting circumneutral and alkaline hot springs in Yellowstone National Park and the US Great Basin. The proteins encoded by these viral polA genes (PolAs) shared no significant sequence similarity with any known viral proteins but were remarkably similar to PolAs encoded by two of three families of the bacterial phylum Aquificae and by several apicoplast-targeted PolA-like proteins found in the eukaryotic phylum Apicomplexa, which includes the obligate parasites Plasmodium, Babesia, and Toxoplasma. The viral gene products share signature elements previously associated only with Aquificae and Apicomplexa PolA-like proteins and were similar to proteins encoded by prophage elements of a variety of otherwise unrelated Bacteria, each of which additionally encoded a prototypical bacterial PolA. Unique among known viral DNA polymerases, the viral PolA proteins of this study share with the Apicomplexa proteins large amino-terminal domains with putative helicase/primase elements but low primary sequence similarity. The genomic context and distribution, phylogeny, and biochemistry of these PolA proteins suggest that thermophilic viruses transferred polA genes to the Apicomplexa, likely through secondary endosymbiosis of a virus-infected proto-apicoplast, and to the common ancestor of two of three Aquificae families, where they displaced the orthologous cellular polA gene. On the basis of biochemical activity, gene structure, and sequence similarity, we speculate that the xenologous viral-type polA genes may have functions associated with diversity-generating recombination in both Bacteria and Apicomplexa.
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19
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Boyd ES, Hamilton TL, Wang J, He L, Zhang CL. The role of tetraether lipid composition in the adaptation of thermophilic archaea to acidity. Front Microbiol 2013; 4:62. [PMID: 23565112 PMCID: PMC3615187 DOI: 10.3389/fmicb.2013.00062] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Accepted: 03/04/2013] [Indexed: 01/10/2023] Open
Abstract
Diether and tetraether lipids are fundamental components of the archaeal cell membrane. Archaea adjust the degree of tetraether lipid cyclization in order to maintain functional membranes and cellular homeostasis when confronted with pH and/or thermal stress. Thus, the ability to adjust tetraether lipid composition likely represents a critical phenotypic trait that enabled archaeal diversification into environments characterized by extremes in pH and/or temperature. Here we assess the relationship between geochemical variation, core- and polar-isoprenoid glycerol dibiphytanyl glycerol tetraether (C-iGDGT and P-iGDGT, respectively) lipid composition, and archaeal 16S rRNA gene diversity and abundance in 27 geothermal springs in Yellowstone National Park, Wyoming. The composition and abundance of C-iGDGT and P-iGDGT lipids recovered from geothermal ecosystems were distinct from surrounding soils, indicating that they are synthesized endogenously. With the exception of GDGT-0 (no cyclopentyl rings), the abundances of individual C-iGDGT and P-iGDGT lipids were significantly correlated. The abundance of a number of individual tetraether lipids varied positively with the relative abundance of individual 16S rRNA gene sequences, most notably crenarchaeol in both the core and polar GDGT fraction and sequences closely affiliated with Candidatus Nitrosocaldus yellowstonii. This finding supports the proposal that crenarchaeol is a biomarker for nitrifying archaea. Variation in the degree of cyclization of C- and P-iGDGT lipids recovered from geothermal mats and sediments could best be explained by variation in spring pH, with lipids from acidic environments tending to have, on average, more internal cyclic rings than those from higher pH ecosystems. Likewise, variation in the phylogenetic composition of archaeal 16S rRNA genes could best be explained by spring pH. In turn, the phylogenetic similarity of archaeal 16S rRNA genes was significantly correlated with the similarity in the composition of C- and P-iGDGT lipids. Taken together, these data suggest that the ability to adjust the composition of GDGT lipid membranes played a central role in the diversification of archaea into or out of environments characterized by extremes of low pH and high temperature.
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Affiliation(s)
- Eric S Boyd
- Department of Chemistry and Biochemistry, Montana State University Bozeman, MT, USA
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20
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Peacock JP, Cole JK, Murugapiran SK, Dodsworth JA, Fisher JC, Moser DP, Hedlund BP. Pyrosequencing reveals high-temperature cellulolytic microbial consortia in Great Boiling Spring after in situ lignocellulose enrichment. PLoS One 2013; 8:e59927. [PMID: 23555835 PMCID: PMC3612082 DOI: 10.1371/journal.pone.0059927] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 02/20/2013] [Indexed: 02/01/2023] Open
Abstract
To characterize high-temperature cellulolytic microbial communities, two lignocellulosic substrates, ammonia fiber-explosion-treated corn stover and aspen shavings, were incubated at average temperatures of 77 and 85°C in the sediment and water column of Great Boiling Spring, Nevada. Comparison of 109,941 quality-filtered 16S rRNA gene pyrosequences (pyrotags) from eight enrichments to 37,057 quality-filtered pyrotags from corresponding natural samples revealed distinct enriched communities dominated by phylotypes related to cellulolytic and hemicellulolytic Thermotoga and Dictyoglomus, cellulolytic and sugar-fermenting Desulfurococcales, and sugar-fermenting and hydrogenotrophic Archaeoglobales. Minor enriched populations included close relatives of hydrogenotrophic Thermodesulfobacteria, the candidate bacterial phylum OP9, and candidate archaeal groups C2 and DHVE3. Enrichment temperature was the major factor influencing community composition, with a negative correlation between temperature and richness, followed by lignocellulosic substrate composition. This study establishes the importance of these groups in the natural degradation of lignocellulose at high temperatures and suggests that a substantial portion of the diversity of thermophiles contributing to consortial cellulolysis may be contained within lineages that have representatives in pure culture.
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Affiliation(s)
- Joseph P Peacock
- School of Life Sciences, University of Nevada, Las Vegas, Nevada, United States of America
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21
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Community microrespirometry and molecular analyses reveal a diverse energy economy in Great Boiling Spring and Sandy's Spring West in the U.S. Great Basin. Appl Environ Microbiol 2013; 79:3306-10. [PMID: 23475616 DOI: 10.1128/aem.00139-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microrespirometry showed that several organic and inorganic electron donors stimulated oxygen consumption in two ∼80°C springs. Sediment and planktonic communities were structurally and functionally distinct, and quantitative PCR revealed catabolically distinct subpopulations of Thermocrinis. This study suggests that a variety of chemolithotrophic metabolisms operate simultaneously in these springs.
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22
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Murugapiran SK, Huntemann M, Wei CL, Han J, Detter JC, Han C, Erkkila TH, Teshima H, Chen A, Kyrpides N, Mavrommatis K, Markowitz V, Szeto E, Ivanova N, Pagani I, Pati A, Goodwin L, Peters L, Pitluck S, Lam J, McDonald AI, Dodsworth JA, Woyke T, Hedlund BP. Thermus oshimai JL-2 and T. thermophilus JL-18 genome analysis illuminates pathways for carbon, nitrogen, and sulfur cycling. Stand Genomic Sci 2013; 7:449-68. [PMID: 24019992 PMCID: PMC3764938 DOI: 10.4056/sigs.3667269] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The complete genomes of Thermus oshimai JL-2 and T. thermophilus JL-18 each consist of a circular chromosome, 2.07 Mb and 1.9 Mb, respectively, and two plasmids ranging from 0.27 Mb to 57.2 kb. Comparison of the T. thermophilus JL-18 chromosome with those from other strains of T. thermophilus revealed a high degree of synteny, whereas the megaplasmids from the same strains were highly plastic. The T. oshimai JL-2 chromosome and megaplasmids shared little or no synteny with other sequenced Thermus strains. Phylogenomic analyses using a concatenated set of conserved proteins confirmed the phylogenetic and taxonomic assignments based on 16S rRNA phylogenetics. Both chromosomes encode a complete glycolysis, tricarboxylic acid (TCA) cycle, and pentose phosphate pathway plus glucosidases, glycosidases, proteases, and peptidases, highlighting highly versatile heterotrophic capabilities. Megaplasmids of both strains contained a gene cluster encoding enzymes predicted to catalyze the sequential reduction of nitrate to nitrous oxide; however, the nitrous oxide reductase required for the terminal step in denitrification was absent, consistent with their incomplete denitrification phenotypes. A sox gene cluster was identified in both chromosomes, suggesting a mode of chemolithotrophy. In addition, nrf and psr gene clusters in T. oshmai JL-2 suggest respiratory nitrite ammonification and polysulfide reduction as possible modes of anaerobic respiration.
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Hou W, Wang S, Dong H, Jiang H, Briggs BR, Peacock JP, Huang Q, Huang L, Wu G, Zhi X, Li W, Dodsworth JA, Hedlund BP, Zhang C, Hartnett HE, Dijkstra P, Hungate BA. A comprehensive census of microbial diversity in hot springs of Tengchong, Yunnan Province China using 16S rRNA gene pyrosequencing. PLoS One 2013; 8:e53350. [PMID: 23326417 PMCID: PMC3541193 DOI: 10.1371/journal.pone.0053350] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 11/27/2012] [Indexed: 11/23/2022] Open
Abstract
The Rehai and Ruidian geothermal fields, located in Tengchong County, Yunnan Province, China, host a variety of geochemically distinct hot springs. In this study, we report a comprehensive, cultivation-independent census of microbial communities in 37 samples collected from these geothermal fields, encompassing sites ranging in temperature from 55.1 to 93.6°C, in pH from 2.5 to 9.4, and in mineralogy from silicates in Rehai to carbonates in Ruidian. Richness was low in all samples, with 21–123 species-level OTUs detected. The bacterial phylum Aquificae or archaeal phylum Crenarchaeota were dominant in Rehai samples, yet the dominant taxa within those phyla depended on temperature, pH, and geochemistry. Rehai springs with low pH (2.5–2.6), high temperature (85.1–89.1°C), and high sulfur contents favored the crenarchaeal order Sulfolobales, whereas those with low pH (2.6–4.8) and cooler temperature (55.1–64.5°C) favored the Aquificae genus Hydrogenobaculum. Rehai springs with neutral-alkaline pH (7.2–9.4) and high temperature (>80°C) with high concentrations of silica and salt ions (Na, K, and Cl) favored the Aquificae genus Hydrogenobacter and crenarchaeal orders Desulfurococcales and Thermoproteales. Desulfurococcales and Thermoproteales became predominant in springs with pH much higher than the optimum and even the maximum pH known for these orders. Ruidian water samples harbored a single Aquificae genus Hydrogenobacter, whereas microbial communities in Ruidian sediment samples were more diverse at the phylum level and distinctly different from those in Rehai and Ruidian water samples, with a higher abundance of uncultivated lineages, close relatives of the ammonia-oxidizing archaeon “Candidatus Nitrosocaldus yellowstonii”, and candidate division O1aA90 and OP1. These differences between Ruidian sediments and Rehai samples were likely caused by temperature, pH, and sediment mineralogy. The results of this study significantly expand the current understanding of the microbiology in Tengchong hot springs and provide a basis for comparison with other geothermal systems around the world.
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Affiliation(s)
- Weiguo Hou
- State Key Laboratory of Biogeology and Environmental Geology and Institute of Earth Sciences, China University of Geosciences, Beijing, China
| | - Shang Wang
- State Key Laboratory of Biogeology and Environmental Geology and Institute of Earth Sciences, China University of Geosciences, Beijing, China
| | - Hailiang Dong
- State Key Laboratory of Biogeology and Environmental Geology and Institute of Earth Sciences, China University of Geosciences, Beijing, China
- Department of Geology and Environmental Earth Science, Miami University, Oxford, Ohio, United States of America
- * E-mail:
| | - Hongchen Jiang
- State Key Laboratory of Biogeology and Environmental Geology and Institute of Earth Sciences, China University of Geosciences, Beijing, China
| | - Brandon R. Briggs
- Department of Geology and Environmental Earth Science, Miami University, Oxford, Ohio, United States of America
| | - Joseph P. Peacock
- School of Life Sciences, University of Nevada, Las Vegas, Nevada, United States of America
| | - Qiuyuan Huang
- Department of Geology and Environmental Earth Science, Miami University, Oxford, Ohio, United States of America
| | - Liuqin Huang
- State Key Laboratory of Biogeology and Environmental Geology and Institute of Earth Sciences, China University of Geosciences, Beijing, China
| | - Geng Wu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, Hubei Province, China
| | - Xiaoyang Zhi
- Key Laboratory of Microbial Diversity in Southwest China of Ministry of Education and Laboratory for Conservation and Utilization of Bio-resources of Yunnan Institute of Microbiology, Yunnan University, Kunming, Yunnan Province, China
| | - Wenjun Li
- Key Laboratory of Microbial Diversity in Southwest China of Ministry of Education and Laboratory for Conservation and Utilization of Bio-resources of Yunnan Institute of Microbiology, Yunnan University, Kunming, Yunnan Province, China
| | - Jeremy A. Dodsworth
- School of Life Sciences, University of Nevada, Las Vegas, Nevada, United States of America
| | - Brian P. Hedlund
- School of Life Sciences, University of Nevada, Las Vegas, Nevada, United States of America
| | - Chuanlun Zhang
- State Key Laboratory of Marine Geology, School of Ocean of Earth Sciences, Tongji University, Shanghai, China
- Department of Marine Sciences, the University of Georgia, Athens, Georgia, United States of America
| | - Hilairy E. Hartnett
- School of Earth and Space Exploration and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, United States of America
| | - Paul Dijkstra
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Bruce A. Hungate
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, United States of America
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Diversity, physiology, and niche differentiation of ammonia-oxidizing archaea. Appl Environ Microbiol 2012; 78:7501-10. [PMID: 22923400 DOI: 10.1128/aem.01960-12] [Citation(s) in RCA: 247] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Nitrification, the aerobic oxidation of ammonia to nitrate via nitrite, has been suggested to have been a central part of the global biogeochemical nitrogen cycle since the oxygenation of Earth. The cultivation of several ammonia-oxidizing archaea (AOA) as well as the discovery that archaeal ammonia monooxygenase (amo)-like gene sequences are nearly ubiquitously distributed in the environment and outnumber their bacterial counterparts in many habitats fundamentally revised our understanding of nitrification. Surprising insights into the physiological distinctiveness of AOA are mirrored by the recognition of the phylogenetic uniqueness of these microbes, which fall within a novel archaeal phylum now known as Thaumarchaeota. The relative importance of AOA in nitrification, compared to ammonia-oxidizing bacteria (AOB), is still under debate. This minireview provides a synopsis of our current knowledge of the diversity and physiology of AOA, the factors controlling their ecology, and their role in carbon cycling as well as their potential involvement in the production of the greenhouse gas nitrous oxide. It emphasizes the importance of activity-based analyses in AOA studies and formulates priorities for future research.
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Hedlund BP, McDonald AI, Lam J, Dodsworth JA, Brown JR, Hungate BA. Potential role of Thermus thermophilus and T. oshimai in high rates of nitrous oxide (N2O) production in ∼80 °C hot springs in the US Great Basin. GEOBIOLOGY 2011; 9:471-480. [PMID: 21951553 DOI: 10.1111/j.1472-4669.2011.00295.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Ambient nitrous oxide (N(2)O) emissions from Great Boiling Spring (GBS) in the US Great Basin depended on temperature, with the highest flux, 67.8 ± 2.6 μmol N(2)O-N m(-2) day(-1) , occurring in the large source pool at 82 °C. This rate of N(2)O production contrasted with negligible production from nearby soils and was similar to rates from soils and sediments impacted with agricultural fertilizers. To investigate the source of N(2)O, a variety of approaches were used to enrich and isolate heterotrophic micro-organisms, and isolates were screened for nitrate reduction ability. Nitrate-respiring isolates were identified by 16S rRNA gene sequencing as Thermus thermophilus (31 isolates) and T. oshimai (three isolates). All isolates reduced nitrate to N(2)O but not to dinitrogen and were unable to grow with N(2)O as a terminal electron acceptor. Representative T. thermophilus and T. oshimai strains contained genes with 96-98% and 93% DNA identity, respectively, to the nitrate reductase catalytic subunit gene (narG) of T. thermophilus HB8. These data implicate T. thermophilus and T. oshimai in high flux of N(2)O in GBS and raise questions about the genetic basis of the incomplete denitrification pathway in these organisms and on the fate of biogenic N(2)O in geothermal environments.
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Affiliation(s)
- B P Hedlund
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, USA.
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Dodsworth JA, Hungate BA, Hedlund BP. Ammonia oxidation, denitrification and dissimilatory nitrate reduction to ammonium in two US Great Basin hot springs with abundant ammonia-oxidizing archaea. Environ Microbiol 2011; 13:2371-86. [PMID: 21631688 DOI: 10.1111/j.1462-2920.2011.02508.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Many thermophiles catalyse free energy-yielding redox reactions involving nitrogenous compounds; however, little is known about these processes in natural thermal environments. Rates of ammonia oxidation, denitrification and dissimilatory nitrate reduction to ammonium (DNRA) were measured in source water and sediments of two ≈ 80°C springs in the US Great Basin. Ammonia oxidation and denitrification occurred mainly in sediments. Ammonia oxidation rates measured using (15)N-NO(3)(-) pool dilution ranged from 5.5 ± 0.8 to 8.6 ± 0.9 nmol N g(-1) h(-1) and were unaffected or only mildly stimulated by amendment with NH(4) Cl. Denitrification rates measured using acetylene block ranged from 15.8 ± 0.7 to 51 ± 12 nmol N g(-1) h(-1) and were stimulated by amendment with NO(3)(-) and complex organic compounds. The DNRA rate in one spring sediment measured using an (15)N-NO(3)(-) tracer was 315 ± 48 nmol N g(-1) h(-1). Both springs harboured distinct planktonic and sediment microbial communities. Close relatives of the autotrophic, ammonia-oxidizing archaeon 'Candidatus Nitrosocaldus yellowstonii' represented the most abundant OTU in both spring sediments by 16S rRNA gene pyrotag analysis. Quantitative PCR (qPCR) indicated that 'Ca. N. yellowstonii'amoA and 16S rRNA genes were present at 3.5-3.9 × 10(8) and 6.4-9.0 × 10(8) copies g(-1) sediment. Potential denitrifiers included members of the Aquificales and Thermales. Thermus spp. comprised <1% of 16S rRNA gene pyrotags in both sediments and qPCR for T. thermophilus narG revealed sediment populations of 1.3-1.7 × 10(6) copies g(-1) sediment. These data indicate a highly active nitrogen cycle (N-cycle) in these springs and suggest that ammonia oxidation may be a major source of energy fuelling primary production.
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Affiliation(s)
- Jeremy A Dodsworth
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA
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