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Qin W, Wei SP, Zheng Y, Choi E, Li X, Johnston J, Wan X, Abrahamson B, Flinkstrom Z, Wang B, Li H, Hou L, Tao Q, Chlouber WW, Sun X, Wells M, Ngo L, Hunt KA, Urakawa H, Tao X, Wang D, Yan X, Wang D, Pan C, Weber PK, Jiang J, Zhou J, Zhang Y, Stahl DA, Ward BB, Mayali X, Martens-Habbena W, Winkler MKH. Ammonia-oxidizing bacteria and archaea exhibit differential nitrogen source preferences. Nat Microbiol 2024; 9:524-536. [PMID: 38297167 DOI: 10.1038/s41564-023-01593-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 12/15/2023] [Indexed: 02/02/2024]
Abstract
Ammonia-oxidizing microorganisms (AOM) contribute to one of the largest nitrogen fluxes in the global nitrogen budget. Four distinct lineages of AOM: ammonia-oxidizing archaea (AOA), beta- and gamma-proteobacterial ammonia-oxidizing bacteria (β-AOB and γ-AOB) and complete ammonia oxidizers (comammox), are thought to compete for ammonia as their primary nitrogen substrate. In addition, many AOM species can utilize urea as an alternative energy and nitrogen source through hydrolysis to ammonia. How the coordination of ammonia and urea metabolism in AOM influences their ecology remains poorly understood. Here we use stable isotope tracing, kinetics and transcriptomics experiments to show that representatives of the AOM lineages employ distinct regulatory strategies for ammonia or urea utilization, thereby minimizing direct substrate competition. The tested AOA and comammox species preferentially used ammonia over urea, while β-AOB favoured urea utilization, repressed ammonia transport in the presence of urea and showed higher affinity for urea than for ammonia. Characterized γ-AOB co-utilized both substrates. These results reveal contrasting niche adaptation and coexistence patterns among the major AOM lineages.
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Affiliation(s)
- Wei Qin
- School of Biological Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA.
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA.
| | - Stephany P Wei
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA
| | - Yue Zheng
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Eunkyung Choi
- Department of Microbiology and Cell Science, Fort Lauderdale Research and Education Center, University of Florida, Davie, FL, USA
| | - Xiangpeng Li
- School of Biological Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | | | - Xianhui Wan
- Department of Geosciences, Princeton University, Princeton, NJ, USA
| | - Britt Abrahamson
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA
| | - Zachary Flinkstrom
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA
| | - Baozhan Wang
- College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Hanyan Li
- School of Biological Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Lei Hou
- School of Biological Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Qing Tao
- School of Biological Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Wyatt W Chlouber
- School of Biological Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Xin Sun
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA
| | - Michael Wells
- School of Biological Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Long Ngo
- School of Biological Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Kristopher A Hunt
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA
| | - Hidetoshi Urakawa
- Department of Ecology and Environmental Studies, Florida Gulf Coast University, Fort Myers, FL, USA
| | - Xuanyu Tao
- School of Biological Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Dongyu Wang
- School of Biological Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Xiaoyuan Yan
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
| | - Dazhi Wang
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Chongle Pan
- School of Biological Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Peter K Weber
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Jiandong Jiang
- College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Jizhong Zhou
- School of Biological Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Yao Zhang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, China
| | - David A Stahl
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA
| | - Bess B Ward
- Department of Geosciences, Princeton University, Princeton, NJ, USA
| | - Xavier Mayali
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Willm Martens-Habbena
- Department of Microbiology and Cell Science, Fort Lauderdale Research and Education Center, University of Florida, Davie, FL, USA.
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Hao Z, Wang Q, Wang J, Deng Y, Yan Z, Tian L, Jiang H. Water Level Fluctuations Modulate the Microbiomes Involved in Biogeochemical Cycling in Floodplains. MICROBIAL ECOLOGY 2023; 87:24. [PMID: 38159125 DOI: 10.1007/s00248-023-02331-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 12/08/2023] [Indexed: 01/03/2024]
Abstract
Drastic changes in hydrological conditions within floodplain ecosystems create distinct microbial habitats. However, there remains a lack of exploration regarding the variations in microbial function potentials across the flooding and drought seasons. In this study, metagenomics and environmental analyses were employed in floodplains that experience hydrological variations across four seasons. Analysis of functional gene composition, encompassing nitrogen, carbon, and sulfur metabolisms, revealed apparent differences between the flooding and drought seasons. The primary environmental drivers identified were water level, overlying water depth, submergence time, and temperature. Specific modules, e.g., the hydrolysis of β-1,4-glucosidic bond, denitrification, and dissimilatory/assimilatory nitrate reduction to ammonium, exhibited higher relative abundance in summer compared to winter. It is suggested that cellulose degradation was potentially coupled with nitrate reduction during the flooding season. Phylogenomic analysis of metagenome-assembled genomes (MAGs) unveiled that the Desulfobacterota lineage possessed abundant nitrogen metabolism genes supported by pathway reconstruction. Variation of relative abundance implied its environmental adaptability to both the wet and dry seasons. Furthermore, a novel order was found within Methylomirabilota, containing nitrogen reduction genes in the MAG. Overall, this study highlights the crucial role of hydrological factors in modulating microbial functional diversity and generating genomes with abundant nitrogen metabolism potentials.
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Affiliation(s)
- Zheng Hao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Qianhong Wang
- Changjiang Nanjing Waterway Engineering Bureau, Nanjing, 210011, China
| | - Jianjun Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
| | - Ye Deng
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Zaisheng Yan
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
| | - Linqi Tian
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
| | - Helong Jiang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China.
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3
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Roveta C, Calcinai B, Girolametti F, Fernandes Couceiro J, Puce S, Annibaldi A, Costa R. The prokaryotic community of Chondrosia reniformis Nardo, 1847: from diversity to mercury detection. ZOOLOGY 2023; 158:126091. [PMID: 37003141 DOI: 10.1016/j.zool.2023.126091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 02/21/2023] [Accepted: 03/16/2023] [Indexed: 03/31/2023]
Abstract
Microbial communities inhabiting sponges are known to take part in many metabolic pathways, including nutrient cycles, and possibly also in the bioaccumulation of trace elements (TEs). Here, we used high-throughput, Illumina sequencing of 16S rRNA genes to characterize the prokaryotic communities present in the cortex and choanosome, respectively the external and internal body region of Chondrosia reniformis, and in the surrounding seawater. Furthermore, we estimated the total mercury content (THg) in these body regions of the sponge and in the corresponding microbial cell pellets. Fifteen prokaryotic phyla were detected in association with C. reniformis, 13 belonging to the domain Bacteria and two to the Archaea. No significant differences between the prokaryotic community composition of the two regions were found. Three lineages of ammonium-oxidizing organisms (Cenarchaeum symbiosum, Nitrosopumilus maritimus, and Nitrosococcus sp.) co-dominated the prokaryotic community, suggesting ammonium oxidation/nitrification as a key metabolic pathway within the microbiome of C. reniformis. In the sponge fractions, higher THg levels were found in the choanosome compared to the cortex. In contrast, comparable THg levels found in the microbial pellets obtained from both regions were significantly lower than those observed in the corresponding sponge fractions. Our work provides new insights into the prokaryotic communities and TEs distribution in different body parts of a model organism relevant for marine conservation and biotechnology. In this sense, this study paves the way for scientists to deepen the possible application of sponges not only as bioindicators, but also as bioremediation tools of metal polluted environments.
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Affiliation(s)
- Camilla Roveta
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy.
| | - Barbara Calcinai
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Federico Girolametti
- Department of Industrial Engineering and Mathematical Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Joana Fernandes Couceiro
- Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal; Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Stefania Puce
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Anna Annibaldi
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Rodrigo Costa
- Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal; Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Centre of Marine Sciences (CCMAR), University of Algarve, Portugal
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Al-Hazmi HE, Hassan GK, Maktabifard M, Grubba D, Majtacz J, Mąkinia J. Integrating conventional nitrogen removal with anammox in wastewater treatment systems: Microbial metabolism, sustainability and challenges. ENVIRONMENTAL RESEARCH 2022; 215:114432. [PMID: 36167115 DOI: 10.1016/j.envres.2022.114432] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/19/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
The various forms of nitrogen (N), including ammonium (NH4+), nitrite (NO2-), and nitrate (NO3-), present in wastewaters can create critical biotic stress and can lead to hazardous phenomena that cause imbalances in biological diversity. Thus, biological nitrogen removal (BNR) from wastewaters is considered to be imperatively urgent. Therefore, anammox-based systems, i.e. partial nitrification and anaerobic ammonium oxidation (PN/anammox) and partial denitrification and anammox (PD/anammox) have been universally acknowledged to consider as alternatives, promising and cost-effective technologies for sustainable N removal from wastewaters compared to nitrification-denitrification processes. This review comprehensively presents and discusses the latest advances in BNR technologies, including traditional nitrification-denitrification and anammox-based systems. To a deep understanding of a better-controlled combining anammox with traditional processes, the microbial community diversity and metabolism, as well as, biomass morphological characteristics were clearly reviewed in the anammox-based systems. Explaining simultaneous microbial competition and control of crucial operation parameters in single-stage anammox-based processes in terms of optimization and economic benefits makes this contribution a different vision from available review papers. The most important sustainability indicators, including global warming potential (GWP), carbon footprint (CF) and energy behaviours were explored to evaluate the sustainability of BNR processes in wastewater treatment. Additionally, the challenges and solutions for BNR processes are extensively discussed. In summary, this review helps facilitate a critical understanding of N removal technologies. It is confirmed that sustainability and saving energy would be achieved by anammox-based systems, thereby could be encouraged future outcomes for a sustainable N removal economy.
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Affiliation(s)
- Hussein E Al-Hazmi
- Department of Sanitary Engineering, Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, Ul. Narutowicza 11/12, Gdańsk, 80-233, Poland.
| | - Gamal K Hassan
- Water Pollution Research Department, National Research Centre, 33 Bohouth St, Giza, Dokki, P.O. Box 12622, Egypt
| | - Mojtaba Maktabifard
- Department of Sanitary Engineering, Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, Ul. Narutowicza 11/12, Gdańsk, 80-233, Poland
| | - Dominika Grubba
- Department of Sanitary Engineering, Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, Ul. Narutowicza 11/12, Gdańsk, 80-233, Poland
| | - Joanna Majtacz
- Department of Sanitary Engineering, Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, Ul. Narutowicza 11/12, Gdańsk, 80-233, Poland
| | - Jacek Mąkinia
- Department of Sanitary Engineering, Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, Ul. Narutowicza 11/12, Gdańsk, 80-233, Poland
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Ecological Aerobic Ammonia and Methane Oxidation Involved Key Metal Compounds, Fe and Cu. Life (Basel) 2022; 12:life12111806. [PMID: 36362966 PMCID: PMC9693385 DOI: 10.3390/life12111806] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 10/25/2022] [Accepted: 11/04/2022] [Indexed: 11/09/2022] Open
Abstract
Interactions between metals and microbes are critical in geomicrobiology and vital in microbial ecophysiological processes. Methane-oxidizing bacteria (MOB) and ammonia-oxidizing microorganisms (AOM) are key members in aerobic environments to start the C and N cycles. Ammonia and methane are firstly oxidized by copper-binding metalloproteins, monooxygenases, and diverse iron and copper-containing enzymes that contribute to electron transportation in the energy gain pathway, which is evolutionally connected between MOB and AOM. In this review, we summarized recently updated insight into the diverse physiological pathway of aerobic ammonia and methane oxidation of different MOB and AOM groups and compared the metabolic diversity mediated by different metalloenzymes. The elevation of iron and copper concentrations in ecosystems would be critical in the activity and growth of MOB and AOM, the outcome of which can eventually influence the global C and N cycles. Therefore, we also described the impact of various concentrations of metal compounds on the physiology of MOB and AOM. This review study could give a fundamental strategy to control MOB and AOM in diverse ecosystems because they are significantly related to climate change, eutrophication, and the remediation of contaminated sites for detoxifying pollutants.
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Waschulin V, Borsetto C, James R, Newsham KK, Donadio S, Corre C, Wellington E. Biosynthetic potential of uncultured Antarctic soil bacteria revealed through long-read metagenomic sequencing. THE ISME JOURNAL 2022; 16:101-111. [PMID: 34253854 PMCID: PMC8692599 DOI: 10.1038/s41396-021-01052-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 06/17/2021] [Accepted: 06/28/2021] [Indexed: 12/31/2022]
Abstract
The growing problem of antibiotic resistance has led to the exploration of uncultured bacteria as potential sources of new antimicrobials. PCR amplicon analyses and short-read sequencing studies of samples from different environments have reported evidence of high biosynthetic gene cluster (BGC) diversity in metagenomes, indicating their potential for producing novel and useful compounds. However, recovering full-length BGC sequences from uncultivated bacteria remains a challenge due to the technological restraints of short-read sequencing, thus making assessment of BGC diversity difficult. Here, long-read sequencing and genome mining were used to recover >1400 mostly full-length BGCs that demonstrate the rich diversity of BGCs from uncultivated lineages present in soil from Mars Oasis, Antarctica. A large number of highly divergent BGCs were not only found in the phyla Acidobacteriota, Verrucomicrobiota and Gemmatimonadota but also in the actinobacterial classes Acidimicrobiia and Thermoleophilia and the gammaproteobacterial order UBA7966. The latter furthermore contained a potential novel family of RiPPs. Our findings underline the biosynthetic potential of underexplored phyla as well as unexplored lineages within seemingly well-studied producer phyla. They also showcase long-read metagenomic sequencing as a promising way to access the untapped genetic reservoir of specialised metabolite gene clusters of the uncultured majority of microbes.
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Affiliation(s)
| | - Chiara Borsetto
- School of Life Sciences, University of Warwick, Coventry, UK
| | | | | | | | - Christophe Corre
- School of Life Sciences, University of Warwick, Coventry, UK
- Department of Chemistry, University of Warwick, Coventry, UK
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Wang B, Huang J, Yang J, Jiang H, Xiao H, Han J, Zhang X. Bicarbonate uptake rates and diversity of RuBisCO genes in saline lake sediments. FEMS Microbiol Ecol 2021; 97:6149456. [PMID: 33629724 DOI: 10.1093/femsec/fiab037] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 02/23/2021] [Indexed: 11/12/2022] Open
Abstract
There is limited knowledge of microbial carbon fixation rate, and carbon-fixing microbial abundance and diversity in saline lakes. In this study, the inorganic carbon uptake rates and carbon-fixing microbial populations were investigated in the surface sediments of lakes with a full range of salinity from freshwater to salt saturation. The results showed that in the studied lakes light-dependent bicarbonate uptake contributed substantially (>70%) to total bicarbonate uptake, while the contribution of dark bicarbonate uptake (1.35-25.17%) cannot be ignored. The light-dependent bicarbonate uptake rates were significantly correlated with pH and turbidity, while dark bicarbonate uptake rates were significantly influenced by dissolved inorganic carbon, pH, temperature and salinity. Carbon-fixing microbial populations using the Calvin-Benson-Bassham pathway were widespread in the studied lakes, and they were dominated by the cbbL and cbbM gene types affiliated with Cyanobacteria and Proteobacteria, respectively. The cbbL and cbbM gene abundance and population structures were significantly affected by different environmental variables, with the cbbL and cbbM genes being negatively correlated with salinity and organic carbon concentration, respectively. In summary, this study improves our knowledge of the abundance, diversity and function of carbon-fixing microbial populations in the lakes with a full range of salinity.
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Affiliation(s)
- Beichen Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Jianrong Huang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Jian Yang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Hongchen Jiang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.,State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
| | - Haiyi Xiao
- Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Jibin Han
- Key Laboratory of Salt Lake Geology and Environment of Qinghai Province, Qinghai Institute of Salt Lakes, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Xining 81008, China
| | - Xiying Zhang
- Key Laboratory of Salt Lake Geology and Environment of Qinghai Province, Qinghai Institute of Salt Lakes, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Xining 81008, China
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Picone N, Pol A, Mesman R, van Kessel MAHJ, Cremers G, van Gelder AH, van Alen TA, Jetten MSM, Lücker S, Op den Camp HJM. Ammonia oxidation at pH 2.5 by a new gammaproteobacterial ammonia-oxidizing bacterium. THE ISME JOURNAL 2021; 15:1150-1164. [PMID: 33303933 PMCID: PMC8115276 DOI: 10.1038/s41396-020-00840-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 11/03/2020] [Accepted: 11/11/2020] [Indexed: 01/29/2023]
Abstract
Ammonia oxidation was considered impossible under highly acidic conditions, as the protonation of ammonia leads to decreased substrate availability and formation of toxic nitrogenous compounds. Recently, some studies described archaeal and bacterial ammonia oxidizers growing at pH as low as 4, while environmental studies observed nitrification at even lower pH values. In this work, we report on the discovery, cultivation, and physiological, genomic, and transcriptomic characterization of a novel gammaproteobacterial ammonia-oxidizing bacterium enriched via continuous bioreactor cultivation from an acidic air biofilter that was able to grow and oxidize ammonia at pH 2.5. This microorganism has a chemolithoautotrophic lifestyle, using ammonia as energy source. The observed growth rate on ammonia was 0.196 day-1, with a doubling time of 3.5 days. The strain also displayed ureolytic activity and cultivation with urea as ammonia source resulted in a growth rate of 0.104 day-1 and a doubling time of 6.7 days. A high ammonia affinity (Km(app) = 147 ± 14 nM) and high tolerance to toxic nitric oxide could represent an adaptation to acidic environments. Electron microscopic analysis showed coccoid cell morphology with a large amount of intracytoplasmic membrane stacks, typical of gammaproteobacterial ammonia oxidizers. Furthermore, genome and transcriptome analysis showed the presence and expression of diagnostic genes for nitrifiers (amoCAB, hao, nor, ure, cbbLS), but no nirK was identified. Phylogenetic analysis revealed that this strain belonged to a novel bacterial genus, for which we propose the name "Candidatus Nitrosacidococcus tergens" sp. RJ19.
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Affiliation(s)
- Nunzia Picone
- grid.5590.90000000122931605Department of Microbiology, IWWR, Radboud University, Heyendaalseweg 135, NL-6525 AJ Nijmegen, The Netherlands
| | - Arjan Pol
- grid.5590.90000000122931605Department of Microbiology, IWWR, Radboud University, Heyendaalseweg 135, NL-6525 AJ Nijmegen, The Netherlands
| | - Rob Mesman
- grid.5590.90000000122931605Department of Microbiology, IWWR, Radboud University, Heyendaalseweg 135, NL-6525 AJ Nijmegen, The Netherlands
| | - Maartje A. H. J. van Kessel
- grid.5590.90000000122931605Department of Microbiology, IWWR, Radboud University, Heyendaalseweg 135, NL-6525 AJ Nijmegen, The Netherlands
| | - Geert Cremers
- grid.5590.90000000122931605Department of Microbiology, IWWR, Radboud University, Heyendaalseweg 135, NL-6525 AJ Nijmegen, The Netherlands
| | - Antonie H. van Gelder
- grid.4818.50000 0001 0791 5666Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Theo A. van Alen
- grid.5590.90000000122931605Department of Microbiology, IWWR, Radboud University, Heyendaalseweg 135, NL-6525 AJ Nijmegen, The Netherlands
| | - Mike S. M. Jetten
- grid.5590.90000000122931605Department of Microbiology, IWWR, Radboud University, Heyendaalseweg 135, NL-6525 AJ Nijmegen, The Netherlands
| | - Sebastian Lücker
- grid.5590.90000000122931605Department of Microbiology, IWWR, Radboud University, Heyendaalseweg 135, NL-6525 AJ Nijmegen, The Netherlands
| | - Huub J. M. Op den Camp
- grid.5590.90000000122931605Department of Microbiology, IWWR, Radboud University, Heyendaalseweg 135, NL-6525 AJ Nijmegen, The Netherlands
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Shafiee RT, Diver PJ, Snow JT, Zhang Q, Rickaby REM. Marine ammonia-oxidising archaea and bacteria occupy distinct iron and copper niches. ISME COMMUNICATIONS 2021; 1:1. [PMID: 37938628 PMCID: PMC9723733 DOI: 10.1038/s43705-021-00001-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/11/2020] [Accepted: 01/06/2021] [Indexed: 12/22/2022]
Abstract
Ammonia oxidation by archaea and bacteria (AOA and AOB), is the first step of nitrification in the oceans. As AOA have an ammonium affinity 200-fold higher than AOB isolates, the chemical niche allowing AOB to persist in the oligotrophic ocean remains unclear. Here we show that marine isolates, Nitrosopumilus maritimus strain SCM1 (AOA) and Nitrosococcus oceani strain C-107 (AOB) have contrasting physiologies in response to the trace metals iron (Fe) and copper (Cu), holding potential implications for their niche separation in the oceans. A greater affinity for unchelated Fe may allow AOB to inhabit shallower, euphotic waters where ammonium supply is high, but competition for Fe is rife. In contrast to AOB, AOA isolates have a greater affinity and toxicity threshold for unchelated Cu providing additional explanation to the greater success of AOA in the marine environment where Cu availability can be highly variable. Using comparative genomics, we predict that the proteomic and metal transport basis giving rise to contrasting physiologies in isolates is widespread across phylogenetically diverse marine AOA and AOB that are not yet available in pure culture. Our results develop the testable hypothesis that ammonia oxidation may be limited by Cu in large tracts of the open ocean and suggest a relatively earlier emergence of AOB than AOA when considered in the context of evolving trace metal availabilities over geologic time.
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Affiliation(s)
- Roxana T Shafiee
- Department of Earth Sciences, University of Oxford, Oxfordshire, UK.
| | - Poppy J Diver
- Department of Earth Sciences, University of Oxford, Oxfordshire, UK
| | - Joseph T Snow
- Department of Earth Sciences, University of Oxford, Oxfordshire, UK
| | - Qiong Zhang
- Department of Earth Sciences, University of Oxford, Oxfordshire, UK
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10
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Steiner PA, Geijo J, Fadeev E, Obiol A, Sintes E, Rattei T, Herndl GJ. Functional Seasonality of Free-Living and Particle-Associated Prokaryotic Communities in the Coastal Adriatic Sea. Front Microbiol 2020; 11:584222. [PMID: 33304331 PMCID: PMC7701263 DOI: 10.3389/fmicb.2020.584222] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 10/23/2020] [Indexed: 01/04/2023] Open
Abstract
Marine snow is an important habitat for microbes, characterized by chemical and physical properties contrasting those of the ambient water. The higher nutrient concentrations in marine snow lead to compositional differences between the ambient water and the marine snow-associated prokaryotic community. Whether these compositional differences vary due to seasonal environmental changes, however, remains unclear. Thus, we investigated the seasonal patterns of the free-living and marine snow-associated microbial community composition and their functional potential in the northern Adriatic Sea. Our data revealed seasonal patterns in both, the free-living and marine snow-associated prokaryotes. The two assemblages were more similar to each other in spring and fall than in winter and summer. The taxonomic distinctness resulted in a contrasting functional potential. Motility and adaptations to low temperature in winter and partly anaerobic metabolism in summer characterized the marine snow-associated prokaryotes. Free-living prokaryotes were enriched in genes indicative for functions related to phosphorus limitation in winter and in genes tentatively supplementing heterotrophic growth with proteorhodopsins and CO-oxidation in summer. Taken together, the results suggest a strong influence of environmental parameters on both free-living and marine snow-associated prokaryotic communities in spring and fall leading to higher similarity between the communities, while the marine snow habitat in winter and summer leads to a specific prokaryotic community in marine snow in these two seasons.
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Affiliation(s)
- Paul A. Steiner
- Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria
| | - Javier Geijo
- Department of Microbiology and Ecosystem Science, Division of Computational Systems Biology, University of Vienna, Vienna, Austria
| | - Eduard Fadeev
- Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria
| | - Aleix Obiol
- Institut de Ciències del Mar, Institut de Ci ncies del Mar – Consejo Superior de Investigaciones Cient ficas (ICM-CSIC), Barcelona, Spain
| | - Eva Sintes
- Instituto Español de Oceanografia, Centre Oceanogràfic de les Balears, Palma, Spain
| | - Thomas Rattei
- Department of Microbiology and Ecosystem Science, Division of Computational Systems Biology, University of Vienna, Vienna, Austria
| | - Gerhard J. Herndl
- Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria
- Royal Netherlands Institute for Sea Research (NIOZ), Department of Marine Microbiology and Biogeochemistry, Utrecht University, Utrecht, Netherlands
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11
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Wang L, Lim CK, Klotz MG. High Synteny and Sequence Identity between Genomes of Nitrosococcus oceani Strains Isolated from Different Oceanic Gyres Reveals Genome Economization and Autochthonous Clonal Evolution. Microorganisms 2020; 8:E693. [PMID: 32397339 PMCID: PMC7285500 DOI: 10.3390/microorganisms8050693] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/18/2020] [Accepted: 05/04/2020] [Indexed: 12/31/2022] Open
Abstract
The ammonia-oxidizing obligate aerobic chemolithoautotrophic gammaproteobacterium, Nitrosococcus oceani, is omnipresent in the world's oceans and as such important to the global nitrogen cycle. We generated and compared high quality draft genome sequences of N. oceani strains isolated from the Northeast (AFC27) and Southeast (AFC132) Pacific Ocean and the coastal waters near Barbados at the interface between the Caribbean Sea and the North Atlantic Ocean (C-27) with the recently published Draft Genome Sequence of N. oceani Strain NS58 (West Pacific Ocean) and the complete genome sequence of N. oceani C-107, the type strain (ATCC 19707) isolated from the open North Atlantic, with the goal to identify indicators for the evolutionary origin of the species. The genomes of strains C-107, NS58, C-27, and AFC27 were highly conserved in content and synteny, and these four genomes contained one nearly sequence-identical plasmid. The genome of strain AFC132 revealed the presence of genetic inventory unknown from other marine ammonia-oxidizing bacteria such as genes encoding NiFe-hydrogenase and a non-ribosomal peptide synthetase (NRPS)-like siderophore biosynthesis module. Comparative genome analysis in context with the literature suggests that AFC132 represents a metabolically more diverse ancestral lineage to the other strains with C-107 and NS58 potentially being the youngest. The results suggest that the N. oceani species evolved by genome economization characterized by the loss of genes encoding catabolic diversity while acquiring a higher redundancy in inventory dedicated to nitrogen catabolism, both of which could have been facilitated by their rich complements of CRISPR/Cas and Restriction Modification systems.
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Affiliation(s)
- Lin Wang
- Department of Biological Sciences, University of North Carolina, 9201 University City Boulevard, Charlotte, NC 28223, USA; (L.W.); (C.K.L.)
| | - Chee Kent Lim
- Department of Biological Sciences, University of North Carolina, 9201 University City Boulevard, Charlotte, NC 28223, USA; (L.W.); (C.K.L.)
| | - Martin G. Klotz
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, 2710 Crimson Way, Richland, WA 99354, USA
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12
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Taylor HB, Kurtz HD. Composition, diversity, and activity of aerobic ammonia-oxidizing Bacteria and Archaea in the intertidal sands of a grand strand South Carolina beach. Microbiologyopen 2020; 9:e1011. [PMID: 32126588 PMCID: PMC7221436 DOI: 10.1002/mbo3.1011] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 01/21/2020] [Accepted: 01/22/2020] [Indexed: 01/22/2023] Open
Abstract
Aerobic ammonia oxidation to nitrite has been established as an important ecosystem process in regulating the level of nitrogen in marine ecosystems. This process is carried out by ammonia-oxidizing bacteria (AOB) within the classes Betaproteobacteria and Gammaproteobacteria and ammonia-oxidizing Archaea (AOA) from the phylum Thaumarchaeota, and the latter of which has been established as more prevalent in marine systems. This study investigated the presence, abundance, and activity of these groups of microbes at a beach near Springmaid Pier in Myrtle Beach, South Carolina, through the implementation of next generation sequencing, quantitative PCR (qPCR), and microcosm experiments to monitor activity. Sequencing analysis revealed a diverse community of ammonia-oxidizing microbes dominated by AOA classified within the family Nitrosopumilaceae, and qPCR revealed the abundance of AOA amoA genes over AOB by at least an order of magnitude in most samples. Microcosm studies indicate that the rates of potential ammonia oxidation in these communities satisfy Michaelis-Menten substrate kinetics and this process is more active at temperatures corresponding to summer months than winter. Potential rates in AOA medium were higher than that of AOB medium, indicating a potentially greater contribution of AOA to this process in this environment. In conclusion, this study provides further evidence of the dominance of AOA in these environments compared with AOB and highlights the overall efficiency of this process at turning over excess ammonium that may be present in these environments.
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Affiliation(s)
- Harrison B Taylor
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, United States
| | - Harry D Kurtz
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, United States
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13
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Zhao MM, Chen YP, Xue LG, Fan TT. Three kinds of ammonia oxidizing microorganisms play an important role in ammonia nitrogen self-purification in the Yellow River. CHEMOSPHERE 2020; 243:125405. [PMID: 31995872 DOI: 10.1016/j.chemosphere.2019.125405] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 10/29/2019] [Accepted: 11/18/2019] [Indexed: 06/10/2023]
Abstract
To develop the microbial resources of the Yellow River, seven water samples were collected along the Lanzhou region of the river from upstream to downstream for testing. Analysis of various physico-chemical indexes was conducted, and key parameters influencing the water quality were selected through principal component analysis, after which the decisive factors impacting water quality were determined by correlation and regression analysis. The results indicated that (1) DO, NH3-N, NO2--N, TN, TC, As, Cr6+ and Pb were the main physico-chemical factors influencing water quality in the Lanzhou region, with NH3-N having the greatest effect. (2) Ammonia-oxidizing microorganisms [ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB), and anaerobic ammonia-oxidizing bacteria (AMX)] were found to mediate the transformation of NH3-N in the studied section. AOA was the primary microbe community among the two aerobic ammonia-oxidizing microorganisms (AOA and AOB) in the Yellow River. (3) Phylogenetic analysis showed that there were some known groups, and there were still many unknown species in the water of the studied section, especially within the AMX population. (4) Correlation analysis revealed that AOA has strong adaptability to unhealthy environments, and that some environmental factors (higher concentrations of carbon, nitrogen and some heavy metals) could increase the AOA gene abundance. Overall, these results suggested there are rich ammonia-oxidizing microbial resources, especially AOA, in the Lanzhou section of the Yellow River, which have the potential for application in nitrogen sewage treatment.
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Affiliation(s)
- Meng M Zhao
- School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou, 730070, China
| | - Yi-Ping Chen
- SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China.
| | - Lin-Gui Xue
- School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou, 730070, China
| | - Tao T Fan
- School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou, 730070, China
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14
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Huan R, Huang J, Liu D, Wang M, Liu C, Zhang Y, Yi C, Xiao D, He H. Genome Sequencing of Mesonia algae K4-1 Reveals Its Adaptation to the Arctic Ocean. Front Microbiol 2019; 10:2812. [PMID: 31866978 PMCID: PMC6905171 DOI: 10.3389/fmicb.2019.02812] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 11/20/2019] [Indexed: 12/27/2022] Open
Abstract
The special ecological environment of the Arctic has brought about a large number of salt-tolerant and psychrotolerant microorganisms. We isolated two culturable bacterial strains of the genus Mesonia; one from the Arctic ocean, Mesonia algae K4-1, and one from the tropical sea, Mesonia sp. HuA40. Our genome analysis and phenotypic experiments indicated that Mesonia algae K4-1 is a moderately halophilic and psychrophilic bacterium. Mesonia algae K4-1 can tolerate 3–14% NaCl and grow at a wide range of temperatures from 4 to 50°C. Mesonia sp. HuA40 is a mesophilic bacterium that can only grow with 3–9% NaCl. In addition, the salt adaptation strategy of Mesonia algae K4-1 accumulates organic osmolytes in the cell. RNA helicases, glutathione and organic compatible solutes may play important roles in maintaining the metabolism and physiological function of Mesonia algae K4-1 under cold stress. Moreover, the ability of Mesonia algae K4-1 to adapt to an oligotrophic marine environment is likely due to the synthesis of a large number of extracellular polysaccharides and the secretion of various families of extracellular proteases. This study systematically analyzed the relationship between genomic differentiation and environmental factors of the Mesonia genus and revealed the possible adaptation mechanism of Mesonia algae K4-1 in the extreme Arctic marine environment at the genomic level.
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Affiliation(s)
- Ran Huan
- School of Life Sciences, Central South University, Changsha, China
| | - JiaFeng Huang
- School of Life Sciences, Central South University, Changsha, China
| | - Dan Liu
- School of Life Sciences, Central South University, Changsha, China
| | - Meng Wang
- School of Life Sciences, Central South University, Changsha, China
| | - CongLing Liu
- School of Life Sciences, Central South University, Changsha, China
| | - YunQian Zhang
- School of Life Sciences, Central South University, Changsha, China
| | - CuiPing Yi
- School of Chemistry and Biological Engineering, Changsha University of Science and Technology, Changsha, China
| | - Dong Xiao
- State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Xuzhou, China
| | - HaiLun He
- School of Life Sciences, Central South University, Changsha, China
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15
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Sedlacek CJ, McGowan B, Suwa Y, Sayavedra-Soto L, Laanbroek HJ, Stein LY, Norton JM, Klotz MG, Bollmann A. A Physiological and Genomic Comparison of Nitrosomonas Cluster 6a and 7 Ammonia-Oxidizing Bacteria. MICROBIAL ECOLOGY 2019; 78:985-994. [PMID: 30976841 DOI: 10.1007/s00248-019-01378-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Accepted: 04/03/2019] [Indexed: 06/09/2023]
Abstract
Ammonia-oxidizing bacteria (AOB) within the genus Nitrosomonas perform the first step in nitrification, ammonia oxidation, and are found in diverse aquatic and terrestrial environments. Nitrosomonas AOB were grouped into six defined clusters, which correlate with physiological characteristics that contribute to adaptations to a variety of abiotic environmental factors. A fundamental physiological trait differentiating Nitrosomonas AOB is the adaptation to either low (cluster 6a) or high (cluster 7) ammonium concentrations. Here, we present physiological growth studies and genome analysis of Nitrosomonas cluster 6a and 7 AOB. Cluster 6a AOB displayed maximum growth rates at ≤ 1 mM ammonium, while cluster 7 AOB had maximum growth rates at ≥ 5 mM ammonium. In addition, cluster 7 AOB were more tolerant of high initial ammonium and nitrite concentrations than cluster 6a AOB. Cluster 6a AOB were completely inhibited by an initial nitrite concentration of 5 mM. Genomic comparisons were used to link genomic traits to observed physiological adaptations. Cluster 7 AOB encode a suite of genes related to nitrogen oxide detoxification and multiple terminal oxidases, which are absent in cluster 6a AOB. Cluster 6a AOB possess two distinct forms of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) and select species encode genes for hydrogen or urea utilization. Several, but not all, cluster 6a AOB can utilize urea as a source of ammonium. Hence, although Nitrosomonas cluster 6a and 7 AOB have the capacity to fulfill the same functional role in microbial communities, i.e., ammonia oxidation, differentiating species-specific and cluster-conserved adaptations is crucial in understanding how AOB community succession can affect overall ecosystem function.
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Affiliation(s)
- Christopher J Sedlacek
- Department of Microbiology, Miami University, 501 East High St, Oxford, OH, 45056, USA
- Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Brian McGowan
- Department of Microbiology, Miami University, 501 East High St, Oxford, OH, 45056, USA
| | - Yuichi Suwa
- Department of Biological Sciences, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo, 112-8551, Japan
| | - Luis Sayavedra-Soto
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97331, USA
| | - Hendrikus J Laanbroek
- Department of Microbial Ecology, Netherlands Institute of Ecology, Droevendaalsesteeg 10, 6708 PB, Wageningen, The Netherlands
| | - Lisa Y Stein
- Department of Biological Sciences, University of Alberta, 116 St. and 85 Ave, Edmonton, AB, T6G 2R3, Canada
| | - Jeanette M Norton
- Department of Plants, Soil and Climate, Utah State University, Logan, UT, 84322-4820, USA
| | - Martin G Klotz
- School of Molecular Biosciences, Washington State University, Richland, WA, 99354, USA
| | - Annette Bollmann
- Department of Microbiology, Miami University, 501 East High St, Oxford, OH, 45056, USA.
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16
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Ben Salem F, Ben Said O, Cravo-Laureau C, Mahmoudi E, Bru N, Monperrus M, Duran R. Bacterial community assemblages in sediments under high anthropogenic pressure at Ichkeul Lake/Bizerte Lagoon hydrological system, Tunisia. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 252:644-656. [PMID: 31185353 DOI: 10.1016/j.envpol.2019.05.146] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 05/27/2019] [Accepted: 05/28/2019] [Indexed: 06/09/2023]
Abstract
Bacterial communities inhabiting sediments in coastal areas endure the effect of strong anthropogenic pressure characterized by the presence of multiple contaminants. Understanding the effect of pollutants on the organization of bacterial communities is of paramount importance in order to unravel bacterial assemblages colonizing specific ecological niches. Here, chemical and molecular approaches were combined to investigate the bacterial communities inhabiting the sediments of the Ichkeul Lake/Bizerte Lagoon, a hydrological system under anthropogenic pressure. Although the microbial community of the Ichkeul Lake sediment was different to that of the Bizerte Lagoon, common bacterial genera were identified suggesting a lake-lagoon continuum probably due to the hydrology of the system exchanging waters according to the season. These genera represent bacterial "generalists" maintaining probably general biogeochemical functions. Linear discriminant analysis effect size (LEfSe) showed significant differential abundance distribution of bacterial genera according to the habitat, the pollution type and level. Further, correlation analyses identified specific bacterial genera which abundance was linked with pesticides concentrations in the lake, while in the lagoon the abundance of specific bacterial genera was found linked with the concentrations of PAHs (Polycyclic aromatic hydrocarbons) and organic forms of Sn. As well, bacterial genera which abundance was not correlated with the concentrations of pollutants were identified in both lake and lagoon. These findings represent valuable information, pointing out specific bacterial genera associated with pollutants, which represent assets for developing bacterial tools for the implementation, the management, and monitoring of bioremediation processes to mitigate the effect of pollutants in aquatic ecosystems.
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Affiliation(s)
- Fida Ben Salem
- Laboratoire de Biosurveillance de l'Environment, Faculté des Sciences de Bizerte, Tunisia; MELODY Group, Université de Pau et des Pays de l'Adour, E2S-UPPA, IPREM UMR CNRS 5254, BP 1155, Pau Cedex, 64013, France; Fédération de recherche MIRA, Université de Pau et des Pays de l'Adour, E2S-UPPA, France
| | - Olfa Ben Said
- Laboratoire de Biosurveillance de l'Environment, Faculté des Sciences de Bizerte, Tunisia; MELODY Group, Université de Pau et des Pays de l'Adour, E2S-UPPA, IPREM UMR CNRS 5254, BP 1155, Pau Cedex, 64013, France; Fédération de recherche MIRA, Université de Pau et des Pays de l'Adour, E2S-UPPA, France
| | - Cristiana Cravo-Laureau
- MELODY Group, Université de Pau et des Pays de l'Adour, E2S-UPPA, IPREM UMR CNRS 5254, BP 1155, Pau Cedex, 64013, France; Fédération de recherche MIRA, Université de Pau et des Pays de l'Adour, E2S-UPPA, France
| | - Ezzeddine Mahmoudi
- Laboratoire de Biosurveillance de l'Environment, Faculté des Sciences de Bizerte, Tunisia
| | - Noëlle Bru
- Laboratoire de Mathématiques et de leurs Applications, PAU UMR CNRS 5142, Université de Pau et des Pays de l'Adour, E2S-UPPA, France; Fédération de recherche MIRA, Université de Pau et des Pays de l'Adour, E2S-UPPA, France
| | - Mathilde Monperrus
- MELODY Group, Université de Pau et des Pays de l'Adour, E2S-UPPA, IPREM UMR CNRS 5254, BP 1155, Pau Cedex, 64013, France; Fédération de recherche MIRA, Université de Pau et des Pays de l'Adour, E2S-UPPA, France
| | - Robert Duran
- MELODY Group, Université de Pau et des Pays de l'Adour, E2S-UPPA, IPREM UMR CNRS 5254, BP 1155, Pau Cedex, 64013, France; Fédération de recherche MIRA, Université de Pau et des Pays de l'Adour, E2S-UPPA, France.
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17
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Draft Genome Sequence of Nitrosococcus oceani Strain NS58, a Marine Ammonia-Oxidizing Gammaproteobacterium Isolated from Tokyo Bay Sediment. Microbiol Resour Announc 2019; 8:8/35/e00923-19. [PMID: 31467109 PMCID: PMC6715879 DOI: 10.1128/mra.00923-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
We report a draft genome sequence of Nitrosococcus oceani strain NS58, isolated from Tokyo Bay sediment. The genome sequence of strain NS58 was nearly identical (>99.99%) to those of other strains of N. oceani isolated from different ocean regions. Only nine single-nucleotide polymorphisms were identified between N. oceani ATCC 19707T and NS58. We report a draft genome sequence of Nitrosococcus oceani strain NS58, isolated from Tokyo Bay sediment. The genome sequence of strain NS58 was nearly identical (>99.99%) to those of other strains of N. oceani isolated from different ocean regions. Only nine single-nucleotide polymorphisms were identified between N. oceani ATCC 19707T and NS58.
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18
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Widner B, Fuchsman CA, Chang BX, Rocap G, Mulholland MR. Utilization of urea and cyanate in waters overlying and within the eastern tropical north Pacific oxygen deficient zone. FEMS Microbiol Ecol 2019; 94:5055141. [PMID: 30016420 DOI: 10.1093/femsec/fiy138] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 07/16/2018] [Indexed: 11/15/2022] Open
Abstract
In marine oxygen deficient zones (ODZs), which contribute up to half of marine N loss, microbes use nitrogen (N) for assimilatory and dissimilatory processes. Here, we examine N utilization above and within the ODZ of the Eastern Tropical North Pacific Ocean, focusing on distribution, uptake and genes for the utilization of two simple organic N compounds, urea and cyanate. Ammonium, urea and cyanate concentrations generally peaked in the oxycline while uptake rates were highest in the surface. Within the ODZ, concentrations were lower, but urea N and C and cyanate C were taken up. All identified autotrophs had an N assimilation pathway that did not require external ammonium: ODZ Prochlorococcus possessed genes to assimilate nitrate, nitrite and urea; nitrite oxidizers (Nitrospina) possessed genes to assimilate nitrite, urea and cyanate; anammox bacteria (Scalindua) possessed genes to utilize cyanate; and ammonia-oxidizing Thaumarchaeota possessed genes to utilize urea. Urease genes were present in 20% of microbes, including SAR11, suggesting the urea utilization capacity was widespread. In the ODZ core, cyanate genes were largely (∼95%) associated with Scalindua, suggesting that, within this ODZ, cyanate N is primarily used for N loss via anammox (cyanammox), and that anammox does not require ammonium for N loss.
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Affiliation(s)
- Brittany Widner
- Department of Ocean, Earth and Atmospheric Sciences, Old Dominion University, Norfolk, USA
| | - Clara A Fuchsman
- University of Washington, School of Oceanography, Seattle, USA.,Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, USA
| | - Bonnie X Chang
- Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, Seattle, USA.,Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, Seattle, USA
| | - Gabrielle Rocap
- University of Washington, School of Oceanography, Seattle, USA
| | - Margaret R Mulholland
- Department of Ocean, Earth and Atmospheric Sciences, Old Dominion University, Norfolk, USA
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19
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Van der Heyden C, De Mulder T, Volcke EIP, Demeyer P, Heyndrickx M, Rasschaert G. Long-term microbial community dynamics at two full-scale biotrickling filters treating pig house exhaust air. Microb Biotechnol 2019; 12:775-786. [PMID: 31106964 PMCID: PMC6559015 DOI: 10.1111/1751-7915.13417] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 03/23/2019] [Accepted: 04/06/2019] [Indexed: 11/30/2022] Open
Abstract
In this study, the microbial community structure of two full‐scale biotrickling filters treating exhaust air from a pig housing facility were evaluated using 16S metabarcoding. The effect of inoculation with activated sludge of a nearby domestic waste water treatment plant was investigated, which is a cheap procedure and easy to apply in practice. The study was performed at a three‐stage and a two‐stage full‐scale biotrickling filter; of which, only the latter was inoculated. Both biotrickling filters evolved towards a rather similar community over time, which differed from the one in the activated sludge used for inoculation. However, the bacterial population at both biotrickling filters showed small differences on the family level. A large population of heterotrophic bacteria, including denitrifying bacteria, was present in both biotrickling filters. In the non‐inoculated biotrickling filter, nitrite‐oxidizing bacteria (NOB) could not be detected, which corresponded with the incomplete nitrification leading to high nitrite accumulation observed in this system. Inoculation with the wide spectrum inoculum activated sludge had in this study a positive effect on the biotrickling filter performance (higher ammonia removal and lower nitrous oxide production). It could thus be beneficial to inoculate biotrickling filters in order to enrich NOB at the start‐up, making it easier to keep the free nitrous acid concentration low enough to not be inhibited by it.
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Affiliation(s)
- Caroline Van der Heyden
- Department of Biosystems Engineering, Ghent University, Coupure links 653, 9000, Gent, Belgium.,Technology and Food Science Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Burgemeester Van Gansberghelaan 115, bus 1, 9820, Merelbeke, Belgium.,Technology and Food Science Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Brusselsesteenweg 370, 9090, Melle, Belgium
| | - Thijs De Mulder
- Technology and Food Science Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Brusselsesteenweg 370, 9090, Melle, Belgium
| | - Eveline I P Volcke
- Department of Biosystems Engineering, Ghent University, Coupure links 653, 9000, Gent, Belgium
| | - Peter Demeyer
- Technology and Food Science Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Burgemeester Van Gansberghelaan 115, bus 1, 9820, Merelbeke, Belgium
| | - Marc Heyndrickx
- Technology and Food Science Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Brusselsesteenweg 370, 9090, Melle, Belgium.,Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Geertui Rasschaert
- Technology and Food Science Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Brusselsesteenweg 370, 9090, Melle, Belgium
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20
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Holmes DE, Dang Y, Smith JA. Nitrogen cycling during wastewater treatment. ADVANCES IN APPLIED MICROBIOLOGY 2019; 106:113-192. [PMID: 30798802 DOI: 10.1016/bs.aambs.2018.10.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Many wastewater treatment plants in the world do not remove reactive nitrogen from wastewater prior to release into the environment. Excess reactive nitrogen not only has a negative impact on human health, it also contributes to air and water pollution, and can cause complex ecosystems to collapse. In order to avoid the deleterious effects of excess reactive nitrogen in the environment, tertiary wastewater treatment practices that ensure the removal of reactive nitrogen species need to be implemented. Many wastewater treatment facilities rely on chemicals for tertiary treatment, however, biological nitrogen removal practices are much more environmentally friendly and cost effective. Therefore, interest in biological treatment is increasing. Biological approaches take advantage of specific groups of microorganisms involved in nitrogen cycling to remove reactive nitrogen from reactor systems by converting ammonia to nitrogen gas. Organisms known to be involved in this process include autotrophic ammonia-oxidizing bacteria, heterotrophic ammonia-oxidizing bacteria, ammonia-oxidizing archaea, anaerobic ammonia oxidizing bacteria (anammox), nitrite-oxidizing bacteria, complete ammonia oxidizers, and dissimilatory nitrate reducing microorganisms. For example, in nitrifying-denitrifying reactors, ammonia- and nitrite-oxidizing bacteria convert ammonia to nitrate and then denitrifying microorganisms reduce nitrate to nonreactive dinitrogen gas. Other nitrogen removal systems (anammox reactors) take advantage of anammox bacteria to convert ammonia to nitrogen gas using NO as an oxidant. A number of promising new biological treatment technologies are emerging and it is hoped that as the cost of these practices goes down more wastewater treatment plants will start to include a tertiary treatment step.
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Ilgrande C, Leroy B, Wattiez R, Vlaeminck SE, Boon N, Clauwaert P. Metabolic and Proteomic Responses to Salinity in Synthetic Nitrifying Communities of Nitrosomonas spp. and Nitrobacter spp. Front Microbiol 2018; 9:2914. [PMID: 30555445 PMCID: PMC6284046 DOI: 10.3389/fmicb.2018.02914] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 11/13/2018] [Indexed: 01/08/2023] Open
Abstract
Typically, nitrification is a two-stage microbial process and is key in wastewater treatment and nutrient recovery from waste streams. Changes in salinity represent a major stress factor that can trigger response mechanisms, impacting the activity and the physiology of bacteria. Despite its pivotal biotechnological role, little information is available on the specific response of nitrifying bacteria to varying levels of salinity. In this study, synthetic communities of ammonia-oxidizing bacteria (AOB Nitrosomonas europaea and/or Nitrosomonas ureae) and nitrite-oxidizing bacteria (NOB Nitrobacter winogradskyi and/or Nitrobacter vulgaris) were tested at 5, 10, and 30 mS cm-1 by adding sodium chloride to the mineral medium (0, 40, and 200 mM NaCl, respectively). Ammonia oxidation activity was less affected by salinity than nitrite oxidation. AOB, on their own or in combination with NOB, showed no significant difference in the ammonia oxidation rate among the three conditions. However, N. winogradskyi improved the absolute ammonia oxidation rate of both N. europaea and N. ureae. N. winogradskyi’s nitrite oxidation rate decreased to 42% residual activity upon exposure to 30 mS cm-1, also showing a similar behavior when tested with Nitrosomonas spp. The nitrite oxidation rate of N. vulgaris, as a single species, was not affected when adding sodium chloride up to 30 mS cm-1, however, its activity was completely inhibited when combined with Nitrosomonas spp. in the presence of ammonium/ammonia. The proteomic analysis of a co-culture of N. europaea and N. winogradskyi revealed the production of osmolytes, regulation of cell permeability and an oxidative stress response in N. europaea and an oxidative stress response in N. winogradskyi, as a result of increasing the salt concentration from 5 to 30 mS cm-1. A specific metabolic response observed in N. europaea suggests the role of carbon metabolism in the production of reducing power, possibly to meet the energy demands of the stress response mechanisms, induced by high salinity. For the first time, metabolic modifications and response mechanisms caused by the exposure to salinity were described, serving as a tool toward controllability and predictability of nitrifying systems exposed to salt fluctuations.
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Affiliation(s)
- Chiara Ilgrande
- Center for Microbial Ecology and Technology, Ghent University, Ghent, Belgium
| | - Baptiste Leroy
- Department of Proteomics and Microbiology, Research institute for Biosciences, University of Mons, Mons, Belgium
| | - Ruddy Wattiez
- Department of Proteomics and Microbiology, Research institute for Biosciences, University of Mons, Mons, Belgium
| | - Siegfried Elias Vlaeminck
- Center for Microbial Ecology and Technology, Ghent University, Ghent, Belgium.,Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Antwerp, Belgium
| | - Nico Boon
- Center for Microbial Ecology and Technology, Ghent University, Ghent, Belgium
| | - Peter Clauwaert
- Center for Microbial Ecology and Technology, Ghent University, Ghent, Belgium
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22
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Osborne CD, Haritos VS. Horizontal gene transfer of three co-inherited methane monooxygenase systems gave rise to methanotrophy in the Proteobacteria. Mol Phylogenet Evol 2018; 129:171-181. [PMID: 30149053 DOI: 10.1016/j.ympev.2018.08.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 08/01/2018] [Accepted: 08/19/2018] [Indexed: 12/22/2022]
Abstract
The critical role that bacterial methanotrophs have in regulating the environmental concentrations of the potent greenhouse gas, methane, under aerobic conditions is dependent on monooxygenase enzymes which oxidise the substrate as both a carbon and energy source. Despite the importance of these organisms, the evolutionary origins of aerobic methane oxidation capability and its relationship to proteobacterial evolution is not well understood. Here we investigated the phylogenetic relationship of proteobacterial methanotrophs with related, non-methanotrophic bacteria using 16S rRNA and the evolution of two forms of methane monooxygenase: membrane bound (pMMO and pXMO) and cytoplasmic (sMMO). Through analysis we have concluded that extant proteobacterial methanotrophs evolved from up to five ancestral species, and that all three methane monooxygenase systems, pMMO, pXMO and sMMO, were likely present in the ancestral species (although pXMO and sMMO are not present in most of the present day methanotrophs). Here we propose that the three monooxygenase systems entered the ancestral species by horizontal gene transfer, with these likely to have pre-existing physiological and metabolic attributes that supported conversion to methanotrophy. Further, we suggest that prior to these enzyme systems developing methane oxidation capabilities, the membrane-bound and cytoplasmic monooxygenases were already both functionally and phylogenetically associated. These results not only suggest that sMMO and pXMO have a far greater role in methanotrophic evolution than previously understood but also implies that the co-inheritance of membrane bound and cytoplasmic monooxygenases have roles additional to that of supporting methanotrophy.
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Affiliation(s)
- Craig D Osborne
- Department of Chemical Engineering, Monash University, Wellington Road, Clayton 3800, Australia
| | - Victoria S Haritos
- Department of Chemical Engineering, Monash University, Wellington Road, Clayton 3800, Australia.
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23
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Heal KR, Qin W, Amin SA, Devol AH, Moffett JW, Armbrust EV, Stahl DA, Ingalls AE. Accumulation of NO 2 -cobalamin in nutrient-stressed ammonia-oxidizing archaea and in the oxygen deficient zone of the eastern tropical North Pacific. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:453-457. [PMID: 30022612 DOI: 10.1111/1758-2229.12664] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 05/22/2018] [Accepted: 05/27/2018] [Indexed: 06/08/2023]
Abstract
Cobalamin (vitamin B12 ) is a precious resource in natural systems that is produced by select prokaryotes and required by a broad range of organisms. In this way, the production of cobalamin reinforces numerous microbial interdependencies. Here we report the accumulation of an unusual form of cobalamin, nitrocobalamin (NO2 -cobalamin), in a marine oxygen deficient zone (ODZ), isolates of ammonia-oxidizing archaea (AOA), and an anaerobic ammonium-oxidizing (anammox) bacteria enriched bioreactor. Low oxygen waters were enriched in NO2 -cobalamin, and AOA isolates experiencing ammonia or copper stress produced more NO2 -cobalamin, though there is wide strain-to-strain and batch-to-batch variability. NO2 -cobalamin has no known biochemical role. We hypothesize that AOA and anammox bacteria are a source of marine NO2 -cobalamin in the environment via a reactive nitrogen intermediate. These findings suggest connections between cobalamin forms and nitrogen transformations, physiological stress and ocean deoxygenation.
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Affiliation(s)
- Katherine R Heal
- School of Oceanography, University of Washington, Seattle, WA, USA
| | - Wei Qin
- School of Oceanography, University of Washington, Seattle, WA, USA
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA
| | - Shady A Amin
- Biology Division, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Allan H Devol
- School of Oceanography, University of Washington, Seattle, WA, USA
| | - James W Moffett
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | | | - David A Stahl
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA
| | - Anitra E Ingalls
- School of Oceanography, University of Washington, Seattle, WA, USA
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24
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Aminoacyl-tRNA synthetases: Structure, function, and drug discovery. Int J Biol Macromol 2018; 111:400-414. [PMID: 29305884 DOI: 10.1016/j.ijbiomac.2017.12.157] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 12/27/2017] [Accepted: 12/29/2017] [Indexed: 01/02/2023]
Abstract
Aminoacyl-tRNA synthetases (AARSs) are the enzymes that catalyze the aminoacylation reaction by covalently linking an amino acid to its cognate tRNA in the first step of protein translation. Beyond this classical function, these enzymes are also known to have a role in several metabolic and signaling pathways that are important for cell viability. Study of these enzymes is of great interest to the researchers due to its pivotal role in the growth and survival of an organism. Further, unfolding the interesting structural and functional aspects of these enzymes in the last few years has qualified them as a potential drug target against various diseases. Here we review the classification, function, and the conserved as well the appended structural architecture of these enzymes in detail, including its association with multi-synthetase complexes. We also considered their role in human diseases in terms of mutations and autoantibodies against AARSs. Finally, we have discussed the available inhibitors against AARSs. This review offers comprehensive information on AARSs under a single canopy that would be a good inventory for researchers working in this area.
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Yasuda T, Waki M, Fukumoto Y, Hanajima D, Kuroda K, Suzuki K, Matsumoto T, Uenishi H. Community structure of denitrifying and total bacteria during nitrogen accumulation in an ammonia‐loaded biofilter. J Appl Microbiol 2017; 123:1498-1511. [DOI: 10.1111/jam.13603] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 09/26/2017] [Accepted: 09/30/2017] [Indexed: 11/29/2022]
Affiliation(s)
- T. Yasuda
- Institute of Livestock and Grassland Science National Agriculture and Food Research Organization Tsukuba Ibaraki Japan
| | - M. Waki
- Institute of Livestock and Grassland Science National Agriculture and Food Research Organization Tsukuba Ibaraki Japan
| | - Y. Fukumoto
- Institute of Livestock and Grassland Science National Agriculture and Food Research Organization Tsukuba Ibaraki Japan
| | - D. Hanajima
- Hokkaido Agricultural Research Center National Agriculture and Food Research Organization Sapporo Hokkaido Japan
| | - K. Kuroda
- Kyushu Okinawa Agricultural Research Center National Agriculture and Food Research Organization Koshi Kumamoto Japan
| | - K. Suzuki
- Institute of Livestock and Grassland Science National Agriculture and Food Research Organization Tsukuba Ibaraki Japan
| | - T. Matsumoto
- Institute of Crop Science National Agricultural and Food Research Organization Tsukuba Ibaraki Japan
| | - H. Uenishi
- Institute of Agrobiological Sciences National Agriculture and Food Research Organization Tsukuba Ibaraki Japan
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26
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Acyl-Homoserine Lactone Production in Nitrifying Bacteria of the Genera Nitrosospira, Nitrobacter, and Nitrospira Identified via a Survey of Putative Quorum-Sensing Genes. Appl Environ Microbiol 2017; 83:AEM.01540-17. [PMID: 28887424 DOI: 10.1128/aem.01540-17] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 08/31/2017] [Indexed: 11/20/2022] Open
Abstract
The genomes of many bacteria that participate in nitrogen cycling through the process of nitrification contain putative genes associated with acyl-homoserine lactone (AHL) quorum sensing (QS). AHL QS or bacterial cell-cell signaling is a method of bacterial communication and gene regulation and may be involved in nitrogen oxide fluxes or other important phenotypes in nitrifying bacteria. Here, we carried out a broad survey of AHL production in nitrifying bacteria in three steps. First, we analyzed the evolutionary history of AHL synthase and AHL receptor homologs in sequenced genomes and metagenomes of nitrifying bacteria to identify AHL synthase homologs in ammonia-oxidizing bacteria (AOB) of the genus Nitrosospira and nitrite-oxidizing bacteria (NOB) of the genera Nitrococcus, Nitrobacter, and Nitrospira Next, we screened cultures of both AOB and NOB with uncharacterized AHL synthase genes and AHL synthase-negative nitrifiers by a bioassay. Our results suggest that an AHL synthase gene is required for, but does not guarantee, cell density-dependent AHL production under the conditions tested. Finally, we utilized mass spectrometry to identify the AHLs produced by the AOB Nitrosospira multiformis and Nitrosospira briensis and the NOB Nitrobacter vulgaris and Nitrospira moscoviensis as N-decanoyl-l-homoserine lactone (C10-HSL), N-3-hydroxy-tetradecanoyl-l-homoserine lactone (3-OH-C14-HSL), a monounsaturated AHL (C10:1-HSL), and N-octanoyl-l-homoserine lactone (C8-HSL), respectively. Our survey expands the list of AHL-producing nitrifiers to include a representative of Nitrospira lineage II and suggests that AHL production is widespread in nitrifying bacteria.IMPORTANCE Nitrification, the aerobic oxidation of ammonia to nitrate via nitrite by nitrifying microorganisms, plays an important role in environmental nitrogen cycling from agricultural fertilization to wastewater treatment. The genomes of many nitrifying bacteria contain genes associated with bacterial cell-cell signaling or quorum sensing (QS). QS is a method of bacterial communication and gene regulation that is well studied in bacterial pathogens, but less is known about QS in environmental systems. Our previous work suggested that QS might be involved in the regulation of nitrogen oxide gas production during nitrite metabolism. This study characterized putative QS signals produced by different genera and species of nitrifiers. Our work lays the foundation for future experiments investigating communication between nitrifying bacteria, the purpose of QS in these microorganisms, and the manipulation of QS during nitrification.
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27
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Distinct taxonomic and functional composition of soil microbiomes along the gradient forest-restinga-mangrove in southeastern Brazil. Antonie van Leeuwenhoek 2017; 111:101-114. [PMID: 28831604 DOI: 10.1007/s10482-017-0931-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 08/17/2017] [Indexed: 02/06/2023]
Abstract
Soil microorganisms play crucial roles in ecosystem functioning, and the central goal in microbial ecology studies is to elucidate which factors shape community structure. A better understanding of the relationship between microbial diversity, functions and environmental parameters would increase our ability to set conservation priorities. Here, the bacterial and archaeal community structure in Atlantic Forest, restinga and mangrove soils was described and compared based on shotgun metagenomics. We hypothesized that each distinct site would harbor a distinct taxonomic and functional soil community, which is influenced by environmental parameters. Our data showed that the microbiome is shaped by soil properties, with pH, base saturation, boron and iron content significantly correlated to overall community structure. When data of specific phyla were correlated to specific soil properties, we demonstrated that parameters such as boron, copper, sulfur, potassium and aluminum presented significant correlation with the most number of bacterial groups. Mangrove soil was the most distinct site and presented the highest taxonomic and functional diversity in comparison with forest and restinga soils. From the total 34 microbial phyla identified, 14 were overrepresented in mangrove soils, including several archaeal groups. Mangrove soils hosted a high abundance of sequences related to replication, survival and adaptation; forest soils included high numbers of sequences related to the metabolism of nutrients and other composts; while restinga soils included abundant genes related to the metabolism of carbohydrates. Overall, our finds show that the microbial community structure and functional potential were clearly different across the environmental gradient, followed by functional adaptation and both were related to the soil properties.
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28
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Dang H, Chen CTA. Ecological Energetic Perspectives on Responses of Nitrogen-Transforming Chemolithoautotrophic Microbiota to Changes in the Marine Environment. Front Microbiol 2017; 8:1246. [PMID: 28769878 PMCID: PMC5509916 DOI: 10.3389/fmicb.2017.01246] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 06/20/2017] [Indexed: 11/15/2022] Open
Abstract
Transformation and mobilization of bioessential elements in the biosphere, lithosphere, atmosphere, and hydrosphere constitute the Earth’s biogeochemical cycles, which are driven mainly by microorganisms through their energy and material metabolic processes. Without microbial energy harvesting from sources of light and inorganic chemical bonds for autotrophic fixation of inorganic carbon, there would not be sustainable ecosystems in the vast ocean. Although ecological energetics (eco-energetics) has been emphasized as a core aspect of ecosystem analyses and microorganisms largely control the flow of matter and energy in marine ecosystems, marine microbial communities are rarely studied from the eco-energetic perspective. The diverse bioenergetic pathways and eco-energetic strategies of the microorganisms are essentially the outcome of biosphere-geosphere interactions over evolutionary times. The biogeochemical cycles are intimately interconnected with energy fluxes across the biosphere and the capacity of the ocean to fix inorganic carbon is generally constrained by the availability of nutrients and energy. The understanding of how microbial eco-energetic processes influence the structure and function of marine ecosystems and how they interact with the changing environment is thus fundamental to a mechanistic and predictive understanding of the marine carbon and nitrogen cycles and the trends in global change. By using major groups of chemolithoautotrophic microorganisms that participate in the marine nitrogen cycle as examples, this article examines their eco-energetic strategies, contributions to carbon cycling, and putative responses to and impacts on the various global change processes associated with global warming, ocean acidification, eutrophication, deoxygenation, and pollution. We conclude that knowledge gaps remain despite decades of tremendous research efforts. The advent of new techniques may bring the dawn to scientific breakthroughs that necessitate the multidisciplinary combination of eco-energetic, biogeochemical and “omics” studies in this field.
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Affiliation(s)
- Hongyue Dang
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, College of Ocean and Earth Sciences, Xiamen UniversityXiamen, China
| | - Chen-Tung A Chen
- Department of Oceanography, National Sun Yat-sen UniversityKaohsiung, Taiwan
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29
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Crenothrix are major methane consumers in stratified lakes. ISME JOURNAL 2017; 11:2124-2140. [PMID: 28585934 PMCID: PMC5563964 DOI: 10.1038/ismej.2017.77] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 04/13/2017] [Accepted: 04/21/2017] [Indexed: 01/29/2023]
Abstract
Methane-oxidizing bacteria represent a major biological sink for methane and are thus Earth’s natural protection against this potent greenhouse gas. Here we show that in two stratified freshwater lakes a substantial part of upward-diffusing methane was oxidized by filamentous gamma-proteobacteria related to Crenothrix polyspora. These filamentous bacteria have been known as contaminants of drinking water supplies since 1870, but their role in the environmental methane removal has remained unclear. While oxidizing methane, these organisms were assigned an ‘unusual’ methane monooxygenase (MMO), which was only distantly related to ‘classical’ MMO of gamma-proteobacterial methanotrophs. We now correct this assignment and show that Crenothrix encode a typical gamma-proteobacterial PmoA. Stable isotope labeling in combination swith single-cell imaging mass spectrometry revealed methane-dependent growth of the lacustrine Crenothrix with oxygen as well as under oxygen-deficient conditions. Crenothrix genomes encoded pathways for the respiration of oxygen as well as for the reduction of nitrate to N2O. The observed abundance and planktonic growth of Crenothrix suggest that these methanotrophs can act as a relevant biological sink for methane in stratified lakes and should be considered in the context of environmental removal of methane.
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30
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Corteselli EM, Aitken MD, Singleton DR. Description of Immundisolibacter cernigliae gen. nov., sp. nov., a high-molecular-weight polycyclic aromatic hydrocarbon-degrading bacterium within the class Gammaproteobacteria, and proposal of Immundisolibacterales ord. nov. and Immundisolibacteraceae fam. nov. Int J Syst Evol Microbiol 2017; 67:925-931. [PMID: 27926817 DOI: 10.1099/ijsem.0.001714] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The bacterial strain TR3.2T was isolated from aerobic bioreactor-treated soil from a polycyclic aromatic hydrocarbon (PAH)-contaminated site in Salisbury, NC, USA. Strain TR3.2T was identified as a member of 'Pyrene Group 2' or 'PG2', a previously uncultivated cluster of organisms associated with the degradation of high-molecular-weight PAHs by stable-isotope probing. Based on its 16S rRNA gene sequence, the strain was classified as a member of the class Gammaproteobacteria but possessed only 90.5 % gene identity to its closest described relative, Methylococcus capsulatus strain Bath. Strain TR3.2T grew on the PAHs pyrene, phenanthrene, anthracene, benz[a]anthracene and fluorene, as well as the azaarene carbazole, and could additionally metabolize a limited number of organic acids. Optimal growth occurred aerobically under mesophilic temperature, neutral pH and low salinity conditions. Strain TR3.2T was catalase and oxidase positive. Predominant fatty acids were C17 : 0 cyclo and C16 : 0. Genomic G+C content of the single chromosome was 67.79 mol% as determined by complete genome sequencing. Due to the high sequence divergence from any cultivated species and its unique physiological properties compared to its closest relatives, strain TR3.2T is proposed as a representative of a novel order, family, genus and species within the class Gammaproteobacteria, for which the name Immundisolibacter cernigliae gen. nov., sp. nov. is proposed. The associated order and family are therefore proposed as Immundisolibacteralesord. nov. and Immundisolibacteraceaefam. nov. The type strain of the species is TR3.2T (=ATCC TSD-58T=DSM 103040T).
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Affiliation(s)
- Elizabeth M Corteselli
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599-7431, USA
| | - Michael D Aitken
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599-7431, USA
| | - David R Singleton
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599-7431, USA
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Hayatsu M, Tago K, Uchiyama I, Toyoda A, Wang Y, Shimomura Y, Okubo T, Kurisu F, Hirono Y, Nonaka K, Akiyama H, Itoh T, Takami H. An acid-tolerant ammonia-oxidizing γ-proteobacterium from soil. ISME JOURNAL 2017; 11:1130-1141. [PMID: 28072419 DOI: 10.1038/ismej.2016.191] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 11/16/2016] [Accepted: 11/19/2016] [Indexed: 12/22/2022]
Abstract
Nitrification, the microbial oxidation of ammonia to nitrate via nitrite, occurs in a wide range of acidic soils. However, the ammonia-oxidizing bacteria (AOB) that have been isolated from soil to date are acid-sensitive. Here we report the isolation and characterization of an acid-adapted AOB from an acidic agricultural soil. The isolated AOB, strain TAO100, is classified within the Gammaproteobacteria based on phylogenetic characteristics. TAO100 can grow in the pH range of 5-7.5 and survive in highly acidic conditions until pH 2 by forming cell aggregates. Whereas all known gammaproteobacterial AOB (γ-AOB) species, which have been isolated from marine and saline aquatic environments, are halophiles, TAO100 is not phenotypically halophilic. Thus, TAO100 represents the first soil-originated and non-halophilic γ-AOB. The TAO100 genome is considerably smaller than those of other γ-AOB and lacks several genes associated with salt tolerance which are unnecessary for survival in soil. The ammonia monooxygenase subunit A gene of TAO100 and its transcript are higher in abundance than those of ammonia-oxidizing archaea and betaproteobacterial AOB in the strongly acidic soil. These results indicate that TAO100 plays an important role in the nitrification of acidic soils. Based on these results, we propose TAO100 as a novel species of a new genus, Candidatus Nitrosoglobus terrae.
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Affiliation(s)
- Masahito Hayatsu
- Institute of Agro-Environmental Science, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Kanako Tago
- Institute of Agro-Environmental Science, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Ikuo Uchiyama
- National Institute for Basic Biology, Okazaki, Aichi, Japan
| | - Atsushi Toyoda
- Center for Information Biology, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Yong Wang
- Institute of Agro-Environmental Science, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Yumi Shimomura
- Institute of Agro-Environmental Science, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Takashi Okubo
- Institute of Agro-Environmental Science, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Futoshi Kurisu
- Research Center for Water Environment Technology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Yuhei Hirono
- Institute of Fruit Tree and Tea Science, NARO, Shimada, Shizuoka, Japan
| | - Kunihiko Nonaka
- Institute of Fruit Tree and Tea Science, NARO, Shimada, Shizuoka, Japan
| | - Hiroko Akiyama
- Institute of Agro-Environmental Science, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Takehiko Itoh
- Graduate School of Bioscience and Biotechnology,Tokyo Institute of Technology, Meguro-ku, Tokyo, Japan
| | - Hideto Takami
- Yokohama Institute, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama, Kanagawa, Japan
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32
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Chistoserdova L. Wide Distribution of Genes for Tetrahydromethanopterin/Methanofuran-Linked C1 Transfer Reactions Argues for Their Presence in the Common Ancestor of Bacteria and Archaea. Front Microbiol 2016; 7:1425. [PMID: 27679616 PMCID: PMC5020050 DOI: 10.3389/fmicb.2016.01425] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 08/29/2016] [Indexed: 12/14/2022] Open
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33
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Kozlowski JA, Kits KD, Stein LY. Comparison of Nitrogen Oxide Metabolism among Diverse Ammonia-Oxidizing Bacteria. Front Microbiol 2016; 7:1090. [PMID: 27462312 PMCID: PMC4940428 DOI: 10.3389/fmicb.2016.01090] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 06/29/2016] [Indexed: 01/05/2023] Open
Abstract
Ammonia-oxidizing bacteria (AOB) have well characterized genes that encode and express nitrite reductases (NIR) and nitric oxide reductases (NOR). However, the connection between presence or absence of these and other genes for nitrogen transformations with the physiological production of nitric oxide (NO) and nitrous oxide (N2O) has not been tested across AOB isolated from various trophic states, with diverse phylogeny, and with closed genomes. It is therefore unclear if genomic content for nitrogen oxide metabolism is predictive of net N2O production. Instantaneous microrespirometry experiments were utilized to measure NO and N2O emitted by AOB during active oxidation of ammonia (NH3) or hydroxylamine (NH2OH) and through a period of anoxia. This data was used in concert with genomic content and phylogeny to assess whether taxonomic factors were predictive of nitrogen oxide metabolism. Results showed that two oligotrophic AOB strains lacking annotated NOR-encoding genes released large quantities of NO and produced N2O abiologically at the onset of anoxia following NH3-oxidation. Furthermore, high concentrations of N2O were measured during active O2-dependent NH2OH oxidation by the two oligotrophic AOB in contrast to non-oligotrophic strains that only produced N2O at the onset of anoxia. Therefore, complete nitrifier denitrification did not occur in the two oligotrophic strains, but did occur in meso- and eutrophic strains, even in Nitrosomonas communis Nm2 that lacks an annotated NIR-encoding gene. Regardless of mechanism, all AOB strains produced measureable N2O under tested conditions. This work further confirms that AOB require NOR activity to enzymatically reduce NO to N2O in the nitrifier denitrification pathway, and also that abiotic reactions play an important role in N2O formation, in oligotrophic AOB lacking NOR activity.
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Affiliation(s)
- Jessica A Kozlowski
- Department of Biological Sciences, Biological Sciences Building, University of Alberta, Edmonton, AB Canada
| | - K Dimitri Kits
- Department of Biological Sciences, Biological Sciences Building, University of Alberta, Edmonton, AB Canada
| | - Lisa Y Stein
- Department of Biological Sciences, Biological Sciences Building, University of Alberta, Edmonton, AB Canada
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Hydrogen peroxide detoxification is a key mechanism for growth of ammonia-oxidizing archaea. Proc Natl Acad Sci U S A 2016; 113:7888-93. [PMID: 27339136 DOI: 10.1073/pnas.1605501113] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Ammonia-oxidizing archaea (AOA), that is, members of the Thaumarchaeota phylum, occur ubiquitously in the environment and are of major significance for global nitrogen cycling. However, controls on cell growth and organic carbon assimilation by AOA are poorly understood. We isolated an ammonia-oxidizing archaeon (designated strain DDS1) from seawater and used this organism to study the physiology of ammonia oxidation. These findings were confirmed using four additional Thaumarchaeota strains from both marine and terrestrial habitats. Ammonia oxidation by strain DDS1 was enhanced in coculture with other bacteria, as well as in artificial seawater media supplemented with α-keto acids (e.g., pyruvate, oxaloacetate). α-Keto acid-enhanced activity of AOA has previously been interpreted as evidence of mixotrophy. However, assays for heterotrophic growth indicated that incorporation of pyruvate into archaeal membrane lipids was negligible. Lipid carbon atoms were, instead, derived from dissolved inorganic carbon, indicating strict autotrophic growth. α-Keto acids spontaneously detoxify H2O2 via a nonenzymatic decarboxylation reaction, suggesting a role of α-keto acids as H2O2 scavengers. Indeed, agents that also scavenge H2O2, such as dimethylthiourea and catalase, replaced the α-keto acid requirement, enhancing growth of strain DDS1. In fact, in the absence of α-keto acids, strain DDS1 and other AOA isolates were shown to endogenously produce H2O2 (up to ∼4.5 μM), which was inhibitory to growth. Genomic analyses indicated catalase genes are largely absent in the AOA. Our results indicate that AOA broadly feature strict autotrophic nutrition and implicate H2O2 as an important factor determining the activity, evolution, and community ecology of AOA ecotypes.
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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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Different Functions of Phylogenetically Distinct Bacterial Complex I Isozymes. J Bacteriol 2016; 198:1268-80. [PMID: 26833419 PMCID: PMC4859585 DOI: 10.1128/jb.01025-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 01/28/2016] [Indexed: 12/12/2022] Open
Abstract
UNLABELLED NADH:quinone oxidoreductase (complex I) is a bioenergetic enzyme that transfers electrons from NADH to quinone, conserving the energy of this reaction by contributing to the proton motive force. While the importance of NADH oxidation to mitochondrial aerobic respiration is well documented, the contribution of complex I to bacterial electron transport chains has been tested in only a few species. Here, we analyze the function of two phylogenetically distinct complex I isozymes in Rhodobacter sphaeroides, an alphaproteobacterium that contains well-characterized electron transport chains. We found that R. sphaeroides complex I activity is important for aerobic respiration and required for anaerobic dimethyl sulfoxide (DMSO) respiration (in the absence of light), photoautotrophic growth, and photoheterotrophic growth (in the absence of an external electron acceptor). Our data also provide insight into the functions of the phylogenetically distinct R. sphaeroidescomplex I enzymes (complex IA and complex IE) in maintaining a cellular redox state during photoheterotrophic growth. We propose that the function of each isozyme during photoheterotrophic growth is either NADH synthesis (complex IA) or NADH oxidation (complex IE). The canonical alphaproteobacterial complex I isozyme (complex IA) was also shown to be important for routing electrons to nitrogenase-mediated H2 production, while the horizontally acquired enzyme (complex IE) was dispensable in this process. Unlike the singular role of complex I in mitochondria, we predict that the phylogenetically distinct complex I enzymes found across bacterial species have evolved to enhance the functions of their respective electron transport chains. IMPORTANCE Cells use a proton motive force (PMF), NADH, and ATP to support numerous processes. In mitochondria, complex I uses NADH oxidation to generate a PMF, which can drive ATP synthesis. This study analyzed the function of complex I in bacteria, which contain more-diverse and more-flexible electron transport chains than mitochondria. We tested complex I function in Rhodobacter sphaeroides, a bacterium predicted to encode two phylogenetically distinct complex I isozymes. R. sphaeroides cells lacking both isozymes had growth defects during all tested modes of growth, illustrating the important function of this enzyme under diverse conditions. We conclude that the two isozymes are not functionally redundant and predict that phylogenetically distinct complex I enzymes have evolved to support the diverse lifestyles of bacteria.
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Liang H, Ye D, Li P, Su T, Wu J, Luo L. Evolution of bacterial consortia in an integrated tannery wastewater treatment process. RSC Adv 2016. [DOI: 10.1039/c6ra19603a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
PCR-DGGE and Illumina HiSeq revealed the composition of bacterial communities in tannery sewage treatment and their linkages with the physicochemical characteristics of wastewater.
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Affiliation(s)
- Hebin Liang
- School of Bioscience and Bioengineering
- South China University of Technology
- Guangzhou
- China
| | - Dongdong Ye
- School of Bioscience and Bioengineering
- South China University of Technology
- Guangzhou
- China
| | - Pan Li
- School of Bioscience and Bioengineering
- South China University of Technology
- Guangzhou
- China
| | - Tingting Su
- School of Bioscience and Bioengineering
- South China University of Technology
- Guangzhou
- China
| | - Jiegen Wu
- School of Bioscience and Bioengineering
- South China University of Technology
- Guangzhou
- China
| | - Lixin Luo
- School of Bioscience and Bioengineering
- South China University of Technology
- Guangzhou
- China
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Daims H, Lebedeva EV, Pjevac P, Han P, Herbold C, Albertsen M, Jehmlich N, Palatinszky M, Vierheilig J, Bulaev A, Kirkegaard RH, von Bergen M, Rattei T, Bendinger B, Nielsen PH, Wagner M. Complete nitrification by Nitrospira bacteria. Nature 2015; 528:504-9. [PMID: 26610024 PMCID: PMC5152751 DOI: 10.1038/nature16461] [Citation(s) in RCA: 1132] [Impact Index Per Article: 125.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 11/19/2015] [Indexed: 11/11/2022]
Abstract
Nitrification, the oxidation of ammonia via nitrite to nitrate, has always been considered to be a two-step process catalysed by chemolithoautotrophic microorganisms oxidizing either ammonia or nitrite. No known nitrifier carries out both steps, although complete nitrification should be energetically advantageous. This functional separation has puzzled microbiologists for a century. Here we report on the discovery and cultivation of a completely nitrifying bacterium from the genus Nitrospira, a globally distributed group of nitrite oxidizers. The genome of this chemolithoautotrophic organism encodes the pathways both for ammonia and nitrite oxidation, which are concomitantly activated during growth by ammonia oxidation to nitrate. Genes affiliated with the phylogenetically distinct ammonia monooxygenase and hydroxylamine dehydrogenase genes of Nitrospira are present in many environments and were retrieved on Nitrospira-contigs in new metagenomes from engineered systems. These findings fundamentally change our picture of nitrification and point to completely nitrifying Nitrospira as key components of nitrogen-cycling microbial communities.
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Affiliation(s)
- Holger Daims
- Department of Microbiology and Ecosystem Science, Division of
Microbial Ecology, University of Vienna, Althanstrasse 14, 1090 Vienna,
Austria
| | - Elena V. Lebedeva
- Winogradsky Institute of Microbiology, Research Center of
Biotechnology of the Russian Academy of Sciences, Leninsky Ave. 33, bld. 2, 119071
Moscow, Russia
| | - Petra Pjevac
- Department of Microbiology and Ecosystem Science, Division of
Microbial Ecology, University of Vienna, Althanstrasse 14, 1090 Vienna,
Austria
| | - Ping Han
- Department of Microbiology and Ecosystem Science, Division of
Microbial Ecology, University of Vienna, Althanstrasse 14, 1090 Vienna,
Austria
| | - Craig Herbold
- Department of Microbiology and Ecosystem Science, Division of
Microbial Ecology, University of Vienna, Althanstrasse 14, 1090 Vienna,
Austria
| | - Mads Albertsen
- Center for Microbial Communities, Department of Chemistry and
Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark
| | - Nico Jehmlich
- Helmholtz-Centre for Environmental Research - UFZ, Department of
Proteomics, Permoserstr. 15, 04318 Leipzig, Germany
| | - Marton Palatinszky
- Department of Microbiology and Ecosystem Science, Division of
Microbial Ecology, University of Vienna, Althanstrasse 14, 1090 Vienna,
Austria
| | - Julia Vierheilig
- Department of Microbiology and Ecosystem Science, Division of
Microbial Ecology, University of Vienna, Althanstrasse 14, 1090 Vienna,
Austria
| | - Alexandr Bulaev
- Winogradsky Institute of Microbiology, Research Center of
Biotechnology of the Russian Academy of Sciences, Leninsky Ave. 33, bld. 2, 119071
Moscow, Russia
| | - Rasmus H. Kirkegaard
- Center for Microbial Communities, Department of Chemistry and
Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark
| | - Martin von Bergen
- Helmholtz-Centre for Environmental Research - UFZ, Department of
Proteomics, Permoserstr. 15, 04318 Leipzig, Germany
- Helmholtz-Centre for Environmental Research - UFZ, Department of
Metabolomics, Permoserstr. 15, 04318 Leipzig, Germany
| | - Thomas Rattei
- Department of Microbiology and Ecosystem Science, Division of
Computational Systems Biology, University of Vienna, Althanstrasse 14, 1090 Vienna,
Austria
| | - Bernd Bendinger
- DVGW-Forschungsstelle TUHH, Hamburg University of Technology, 21073
Hamburg, Germany
| | - Per H. Nielsen
- Center for Microbial Communities, Department of Chemistry and
Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark
| | - Michael Wagner
- Department of Microbiology and Ecosystem Science, Division of
Microbial Ecology, University of Vienna, Althanstrasse 14, 1090 Vienna,
Austria
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Perez-Garcia O, Chandran K, Villas-Boas SG, Singhal N. Assessment of nitric oxide (NO) redox reactions contribution to nitrous oxide (N2 O) formation during nitrification using a multispecies metabolic network model. Biotechnol Bioeng 2015; 113:1124-36. [PMID: 26551878 DOI: 10.1002/bit.25880] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Revised: 09/29/2015] [Accepted: 11/01/2015] [Indexed: 12/20/2022]
Abstract
Over the coming decades nitrous oxide (N2O) is expected to become a dominant greenhouse gas and atmospheric ozone depleting substance. In wastewater treatment systems, N2O is majorly produced by nitrifying microbes through biochemical reduction of nitrite (NO2(-)) and nitric oxide (NO). However it is unknown if the amount of N2O formed is affected by alternative NO redox reactions catalyzed by oxidative nitrite oxidoreductase (NirK), cytochromes (i.e., P460 [CytP460] and 554 [Cyt554 ]) and flavohemoglobins (Hmp) in ammonia- and nitrite-oxidizing bacteria (AOB and NOB, respectively). In this study, a mathematical model is developed to assess how N2O formation is affected by such alternative nitrogen redox transformations. The developed multispecies metabolic network model captures the nitrogen respiratory pathways inferred from genomes of eight AOB and NOB species. The performance of model variants, obtained as different combinations of active NO redox reactions, was assessed against nine experimental datasets for nitrifying cultures producing N2O at different concentration of electron donor and acceptor. Model predicted metabolic fluxes show that only variants that included NO oxidation to NO2(-) by CytP460 and Hmp in AOB gave statistically similar estimates to observed production rates of N2O, NO, NO2(-) and nitrate (NO3(-)), together with fractions of AOB and NOB species in biomass. Simulations showed that NO oxidation to NO2(-) decreased N2O formation by 60% without changing culture's NO2(-) production rate. Model variants including NO reduction to N2O by Cyt554 and cNor in NOB did not improve the accuracy of experimental datasets estimates, suggesting null N2O production by NOB during nitrification. Finally, the analysis shows that in nitrifying cultures transitioning from dissolved oxygen levels above 3.8 ± 0.38 to <1.5 ± 0.8 mg/L, NOB cells can oxidize the NO produced by AOB through reactions catalyzed by oxidative NirK.
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Affiliation(s)
- Octavio Perez-Garcia
- Department of Civil and Environmental Engineering, University of Auckland, 20 Symonds Street, Auckland, New Zealand.
| | - Kartik Chandran
- Department of Earth and Environmental Engineering, Columbia University, New York, New York
| | - Silas G Villas-Boas
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Naresh Singhal
- Department of Civil and Environmental Engineering, University of Auckland, 20 Symonds Street, Auckland, New Zealand.
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40
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Berg C, Listmann L, Vandieken V, Vogts A, Jürgens K. Chemoautotrophic growth of ammonia-oxidizing Thaumarchaeota enriched from a pelagic redox gradient in the Baltic Sea. Front Microbiol 2015; 5:786. [PMID: 25642221 PMCID: PMC4295551 DOI: 10.3389/fmicb.2014.00786] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 12/21/2014] [Indexed: 11/15/2022] Open
Abstract
Ammonia-oxidizing archaea (AOA) are an important component of the planktonic community in aquatic habitats, linking nitrogen and carbon cycles through nitrification and carbon fixation. Therefore, measurements of these processes in culture-based experiments can provide insights into their contributions to energy conservation and biomass production by specific AOA. In this study, by enriching AOA from a brackish, oxygen-depleted water-column in the Landsort Deep, central Baltic Sea, we were able to investigate ammonium oxidation, chemoautotrophy, and growth in seawater batch experiments. The highly enriched culture consisted of up to 97% archaea, with maximal archaeal numbers of 2.9 × 107 cells mL−1. Phylogenetic analysis of the 16S rRNA and ammonia monooxygenase subunit A (amoA) gene sequences revealed an affiliation with assemblages from low-salinity and freshwater habitats, with Candidatus Nitrosoarchaeum limnia as the closest relative. Growth correlated significantly with nitrite production, ammonium consumption, and CO2 fixation, which occurred at a ratio of 10 atoms N oxidized per 1 atom C fixed. According to the carbon balance, AOA biomass production can be entirely explained by chemoautotrophy. The cellular carbon content was estimated to be 9 fg C per cell. Single-cell-based 13C and 15N labeling experiments and analysis by nano-scale secondary ion mass spectrometry provided further evidence that cellular carbon was derived from bicarbonate and that ammonium was taken up by the cells. Our study therefore revealed that growth by an AOA belonging to the genus Nitrosoarchaeum can be sustained largely by chemoautotrophy.
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Affiliation(s)
- Carlo Berg
- Biological Oceanography, Leibniz Institute for Baltic Sea Research Warnemünde (IOW) Rostock, Germany
| | - Luisa Listmann
- Biological Oceanography, Leibniz Institute for Baltic Sea Research Warnemünde (IOW) Rostock, Germany
| | - Verona Vandieken
- Biological Oceanography, Leibniz Institute for Baltic Sea Research Warnemünde (IOW) Rostock, Germany ; Paleomicrobiology Group, Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University of Oldenburg Oldenburg, Germany
| | - Angela Vogts
- Biological Oceanography, Leibniz Institute for Baltic Sea Research Warnemünde (IOW) Rostock, Germany
| | - Klaus Jürgens
- Biological Oceanography, Leibniz Institute for Baltic Sea Research Warnemünde (IOW) Rostock, Germany
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41
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Offre P, Kerou M, Spang A, Schleper C. Variability of the transporter gene complement in ammonia-oxidizing archaea. Trends Microbiol 2014; 22:665-75. [PMID: 25169021 DOI: 10.1016/j.tim.2014.07.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 07/17/2014] [Accepted: 07/30/2014] [Indexed: 12/19/2022]
Abstract
Ammonia-oxidizing archaea (AOA) are a widespread and abundant component of microbial communities in many different ecosystems. The extent of physiological differences between individual AOA is, however, unknown. Here, we compare the transporter gene complements of six AOA, from four different environments and two major clades, to assess their potential for substrate uptake and efflux. Each of the corresponding AOA genomes encode a unique set of transporters and although the composition of AOA transporter complements follows a phylogenetic pattern, few transporter families are conserved in all investigated genomes. A comparison of ammonia transporters encoded by archaeal and bacterial ammonia oxidizers highlights the variance among AOA lineages as well as their distinction from the ammonia-oxidizing bacteria, and suggests differential ecological adaptations.
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Affiliation(s)
- Pierre Offre
- University of Vienna, Department of Ecogenomics and Systems Biology, Archaea Biology and Ecogenomics Division, Althanstrasse 14, A-1090 Wien, Austria.
| | - Melina Kerou
- University of Vienna, Department of Ecogenomics and Systems Biology, Archaea Biology and Ecogenomics Division, Althanstrasse 14, A-1090 Wien, Austria
| | - Anja Spang
- Uppsala University, Department of Cell and Molecular Biology, Science for Life Laboratory, Box 596, SE-75123, Uppsala, Sweden
| | - Christa Schleper
- University of Vienna, Department of Ecogenomics and Systems Biology, Archaea Biology and Ecogenomics Division, Althanstrasse 14, A-1090 Wien, Austria.
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Subramanian M, Srinivasan T, Sudarsanam D. Examining the Gm18 and m(1)G Modification Positions in tRNA Sequences. Genomics Inform 2014; 12:71-5. [PMID: 25031570 PMCID: PMC4099351 DOI: 10.5808/gi.2014.12.2.71] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 03/20/2014] [Accepted: 03/26/2014] [Indexed: 12/30/2022] Open
Abstract
The tRNA structure contains conserved modifications that are responsible for its stability and are involved in the initiation and accuracy of the translation process. tRNA modification enzymes are prevalent in bacteria, archaea, and eukaryotes. tRNA Gm18 methyltransferase (TrmH) and tRNA m1G37 methyltransferase (TrmD) are prevalent and essential enzymes in bacterial populations. TrmH involves itself in methylation process at the 2'-OH group of ribose at the 18th position of guanosine (G) in tRNAs. TrmD methylates the G residue next to the anticodon in selected tRNA subsets. Initially, m1G37 modification was reported to take place on three conserved tRNA subsets (tRNAArg, tRNALeu, tRNAPro); later on, few archaea and eukaryotes organisms revealed that other tRNAs also have the m1G37 modification. The present study reveals Gm18, m1G37 modification, and positions of m1G that take place next to the anticodon in tRNA sequences. We selected extremophile organisms and attempted to retrieve the m1G and Gm18 modification bases in tRNA sequences. Results showed that the Gm18 modification G residue occurs in all tRNA subsets except three tRNAs (tRNAMet, tRNAPro, tRNAVal). Whereas the m1G37 modification base G is formed only on tRNAArg, tRNALeu, tRNAPro, and tRNAHis, the rest of the tRNAs contain adenine (A) next to the anticodon. Thus, we hypothesize that Gm18 modification and m1G modification occur irrespective of a G residue in tRNAs.
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Affiliation(s)
- Mayavan Subramanian
- Synthetic Biology and Biofuel Group, International Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi 110 067, India
| | - Thangavelu Srinivasan
- DST-FIST Bioinformatics and Principal Investigator, School of Genomics and Bioinformatics, Department of Advanced Zoology and Biotechnology, Loyola College, Chennai 600 034, India
| | - Dorairaj Sudarsanam
- DST-FIST Bioinformatics and Principal Investigator, School of Genomics and Bioinformatics, Department of Advanced Zoology and Biotechnology, Loyola College, Chennai 600 034, India
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43
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Keluskar R, Nerurkar A, Desai A. Mutualism between autotrophic ammonia-oxidizing bacteria (AOB) and heterotrophs present in an ammonia-oxidizing colony. Arch Microbiol 2013; 195:737-47. [DOI: 10.1007/s00203-013-0926-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 09/01/2013] [Accepted: 09/05/2013] [Indexed: 10/26/2022]
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Stein LY, Campbell MA, Klotz MG. Energy-mediated vs. ammonium-regulated gene expression in the obligate ammonia-oxidizing bacterium, Nitrosococcus oceani. Front Microbiol 2013; 4:277. [PMID: 24062734 PMCID: PMC3772326 DOI: 10.3389/fmicb.2013.00277] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Accepted: 08/26/2013] [Indexed: 12/04/2022] Open
Abstract
Ammonia serves as the source of energy and reductant and as a signaling molecule that regulates gene expression in obligate ammonia-oxidizing chemolithotrophic microorganisms. The gammaproteobacterium, Nitrosococcus oceani, was the first obligate ammonia-oxidizer isolated from seawater and is one of the model systems for ammonia chemolithotrophy. We compared global transcriptional responses to ammonium and the catabolic intermediate, hydroxylamine, in ammonium-starved and non-starved cultures of N. oceani to discriminate transcriptional effects of ammonium from a change in overall energy and redox status upon catabolite availability. The most highly expressed genes from ammonium- or hydroxylamine-treated relative to starved cells are implicated in catabolic electron flow, carbon fixation, nitrogen assimilation, ribosome structure and stress tolerance. Catabolic inventory-encoding genes, including electron flow-terminating Complexes IV, FoF1 ATPase, transporters, and transcriptional regulators were among the most highly expressed genes in cells exposed only to ammonium relative to starved cells, although the differences compared to steady-state transcript levels were less pronounced. Reduction in steady-state mRNA levels from hydroxylamine-treated relative to starved-cells were less than five-fold. In contrast, several transcripts from ammonium-treated relative to starved cells were significantly less abundant including those for forward Complex I and a gene cluster of cytochrome c encoding proteins. Identified uneven steady-state transcript levels of co-expressed clustered genes support previously reported differential regulation at the levels of transcription and transcript stability. Our results differentiated between rapid regulation of core genes upon a change in cellular redox status vs. those responsive to ammonium as a signaling molecule in N. oceani, both confirming and extending our knowledge of metabolic modules involved in ammonia chemolithotrophy.
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Affiliation(s)
- Lisa Y Stein
- Department of Biological Sciences, University of Alberta Edmonton, AB, Canada
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45
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The (d)evolution of methanotrophy in the Beijerinckiaceae--a comparative genomics analysis. ISME JOURNAL 2013; 8:369-82. [PMID: 23985741 DOI: 10.1038/ismej.2013.145] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 07/17/2013] [Accepted: 07/24/2013] [Indexed: 01/26/2023]
Abstract
The alphaproteobacterial family Beijerinckiaceae contains generalists that grow on a wide range of substrates, and specialists that grow only on methane and methanol. We investigated the evolution of this family by comparing the genomes of the generalist organotroph Beijerinckia indica, the facultative methanotroph Methylocella silvestris and the obligate methanotroph Methylocapsa acidiphila. Highly resolved phylogenetic construction based on universally conserved genes demonstrated that the Beijerinckiaceae forms a monophyletic cluster with the Methylocystaceae, the only other family of alphaproteobacterial methanotrophs. Phylogenetic analyses also demonstrated a vertical inheritance pattern of methanotrophy and methylotrophy genes within these families. Conversely, many lateral gene transfer (LGT) events were detected for genes encoding carbohydrate transport and metabolism, energy production and conversion, and transcriptional regulation in the genome of B. indica, suggesting that it has recently acquired these genes. A key difference between the generalist B. indica and its specialist methanotrophic relatives was an abundance of transporter elements, particularly periplasmic-binding proteins and major facilitator transporters. The most parsimonious scenario for the evolution of methanotrophy in the Alphaproteobacteria is that it occurred only once, when a methylotroph acquired methane monooxygenases (MMOs) via LGT. This was supported by a compositional analysis suggesting that all MMOs in Alphaproteobacteria methanotrophs are foreign in origin. Some members of the Beijerinckiaceae subsequently lost methanotrophic functions and regained the ability to grow on multicarbon energy substrates. We conclude that B. indica is a recidivist multitroph, the only known example of a bacterium having completely abandoned an evolved lifestyle of specialized methanotrophy.
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Hanson TE, Campbell BJ, Kalis KM, Campbell MA, Klotz MG. Nitrate ammonification by Nautilia profundicola AmH: experimental evidence consistent with a free hydroxylamine intermediate. Front Microbiol 2013; 4:180. [PMID: 23847604 PMCID: PMC3701875 DOI: 10.3389/fmicb.2013.00180] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 06/15/2013] [Indexed: 11/13/2022] Open
Abstract
The process of nitrate reduction via nitrite controls the fate and bioavailability of mineral nitrogen within ecosystems; i.e., whether it is retained as ammonium (ammonification) or lost as nitrous oxide or dinitrogen (denitrification). Here, we present experimental evidence for a novel pathway of microbial nitrate reduction, the reverse hydroxylamine:ubiquinone reductase module (reverse-HURM) pathway. Instead of a classical ammonia-forming nitrite reductase that performs a 6 electron-transfer process, the pathway is thought to employ two catalytic redox modules operating in sequence: the reverse-HURM reducing nitrite to hydroxylamine followed by a hydroxylamine reductase that converts hydroxylamine to ammonium. Experiments were performed on Nautilia profundicola strain AmH, whose genome sequence led to the reverse-HURM pathway proposal. N. profundicola produced ammonium from nitrate, which was assimilated into biomass. Furthermore, genes encoding the catalysts of the reverse-HURM pathway were preferentially expressed during growth of N. profundicola on nitrate as an electron acceptor relative to cultures grown on polysulfide as an electron acceptor. Finally, nitrate-grown cells of N. profundicola were able to rapidly and stoichiometrically convert high concentrations of hydroxylamine to ammonium in resting cell assays. These experiments are consistent with the reverse-HURM pathway and a free hydroxylamine intermediate, but could not definitively exclude direct nitrite reduction to ammonium by the reverse-HURM with hydroxylamine as an off-pathway product. N. profundicola and related organisms are models for a new pathway of nitrate ammonification that may have global impact due to the wide distribution of these organisms in hypoxic environments and symbiotic or pathogenic associations with animal hosts.
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Affiliation(s)
- Thomas E Hanson
- School of Marine Science and Policy, University of Delaware Newark, DE, USA ; Delaware Biotechnology Institute, University of Delaware Newark, DE, USA
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Defining the functional potential and active community members of a sediment microbial community in a high-arctic hypersaline subzero spring. Appl Environ Microbiol 2013; 79:3637-48. [PMID: 23563939 DOI: 10.1128/aem.00153-13] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Lost Hammer (LH) Spring is the coldest and saltiest terrestrial spring discovered to date and is characterized by perennial discharges at subzero temperatures (-5°C), hypersalinity (salinity, 24%), and reducing (≈-165 mV), microoxic, and oligotrophic conditions. It is rich in sulfates (10.0%, wt/wt), dissolved H2S/sulfides (up to 25 ppm), ammonia (≈381 μM), and methane (11.1 g day(-1)). To determine its total functional and genetic potential and to identify its active microbial components, we performed metagenomic analyses of the LH Spring outlet microbial community and pyrosequencing analyses of the cDNA of its 16S rRNA genes. Reads related to Cyanobacteria (19.7%), Bacteroidetes (13.3%), and Proteobacteria (6.6%) represented the dominant phyla identified among the classified sequences. Reconstruction of the enzyme pathways responsible for bacterial nitrification/denitrification/ammonification and sulfate reduction appeared nearly complete in the metagenomic data set. In the cDNA profile of the LH Spring active community, ammonia oxidizers (Thaumarchaeota), denitrifiers (Pseudomonas spp.), sulfate reducers (Desulfobulbus spp.), and other sulfur oxidizers (Thermoprotei) were present, highlighting their involvement in nitrogen and sulfur cycling. Stress response genes for adapting to cold, osmotic stress, and oxidative stress were also abundant in the metagenome. Comparison of the composition of the functional community of the LH Spring to metagenomes from other saline/subzero environments revealed a close association between the LH Spring and another Canadian high-Arctic permafrost environment, particularly in genes related to sulfur metabolism and dormancy. Overall, this study provides insights into the metabolic potential and the active microbial populations that exist in this hypersaline cryoenvironment and contributes to our understanding of microbial ecology in extreme environments.
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Abstract
The aminoacyl-tRNA synthetases (aaRSs) are essential components of the protein synthesis machinery responsible for defining the genetic code by pairing the correct amino acids to their cognate tRNAs. The aaRSs are an ancient enzyme family believed to have origins that may predate the last common ancestor and as such they provide insights into the evolution and development of the extant genetic code. Although the aaRSs have long been viewed as a highly conserved group of enzymes, findings within the last couple of decades have started to demonstrate how diverse and versatile these enzymes really are. Beyond their central role in translation, aaRSs and their numerous homologs have evolved a wide array of alternative functions both inside and outside translation. Current understanding of the emergence of the aaRSs, and their subsequent evolution into a functionally diverse enzyme family, are discussed in this chapter.
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French E, Kozlowski JA, Mukherjee M, Bullerjahn G, Bollmann A. Ecophysiological characterization of ammonia-oxidizing archaea and bacteria from freshwater. Appl Environ Microbiol 2012; 78:5773-80. [PMID: 22685142 PMCID: PMC3406153 DOI: 10.1128/aem.00432-12] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 05/30/2012] [Indexed: 11/20/2022] Open
Abstract
Aerobic biological ammonia oxidation is carried out by two groups of microorganisms, ammonia-oxidizing bacteria (AOB) and the recently discovered ammonia-oxidizing archaea (AOA). Here we present a study using cultivation-based methods to investigate the differences in growth of three AOA cultures and one AOB culture enriched from freshwater environments. The strain in the enriched AOA culture belong to thaumarchaeal group I.1a, with the strain in one enrichment culture having the highest identity with "Candidatus Nitrosoarchaeum koreensis" and the strains in the other two representing a new genus of AOA. The AOB strain in the enrichment culture was also obtained from freshwater and had the highest identity to AOB from the Nitrosomonas oligotropha group (Nitrosomonas cluster 6a). We investigated the influence of ammonium, oxygen, pH, and light on the growth of AOA and AOB. The growth rates of the AOB increased with increasing ammonium concentrations, while the growth rates of the AOA decreased slightly. Increasing oxygen concentrations led to an increase in the growth rate of the AOB, while the growth rates of AOA were almost oxygen insensitive. Light exposure (white and blue wavelengths) inhibited the growth of AOA completely, and the AOA did not recover when transferred to the dark. AOB were also inhibited by blue light; however, growth recovered immediately after transfer to the dark. Our results show that the tested AOB have a competitive advantage over the tested AOA under most conditions investigated. Further experiments will elucidate the niches of AOA and AOB in more detail.
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Affiliation(s)
| | | | - Maitreyee Mukherjee
- Bowling Green State University, Department of Biological Sciences, Bowling Green, Ohio, USA
| | - George Bullerjahn
- Bowling Green State University, Department of Biological Sciences, Bowling Green, Ohio, USA
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