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Aronson HS, Clark CE, LaRowe DE, Amend JP, Polerecky L, Macalady JL. Sulfur disproportionating microbial communities in a dynamic, microoxic-sulfidic karst system. GEOBIOLOGY 2023; 21:791-803. [PMID: 37721188 DOI: 10.1111/gbi.12574] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 07/24/2023] [Accepted: 08/29/2023] [Indexed: 09/19/2023]
Abstract
Biogeochemical sulfur cycling in sulfidic karst systems is largely driven by abiotic and biological sulfide oxidation, but the fate of elemental sulfur (S0 ) that accumulates in these systems is not well understood. The Frasassi Cave system (Italy) is intersected by a sulfidic aquifer that mixes with small quantities of oxygen-rich meteoric water, creating Proterozoic-like conditions and supporting a prolific ecosystem driven by sulfur-based chemolithoautotrophy. To better understand the cycling of S0 in this environment, we examined the geochemistry and microbiology of sediments underlying widespread sulfide-oxidizing mats dominated by Beggiatoa. Sediment populations were dominated by uncultivated relatives of sulfur cycling chemolithoautotrophs related to Sulfurovum, Halothiobacillus, Thiofaba, Thiovirga, Thiobacillus, and Desulfocapsa, as well as diverse uncultivated anaerobic heterotrophs affiliated with Bacteroidota, Anaerolineaceae, Lentimicrobiaceae, and Prolixibacteraceae. Desulfocapsa and Sulfurovum populations accounted for 12%-26% of sediment 16S rRNA amplicon sequences and were closely related to isolates which carry out autotrophic S0 disproportionation in pure culture. Gibbs energy (∆Gr ) calculations revealed that S0 disproportionation under in situ conditions is energy yielding. Microsensor profiles through the mat-sediment interface showed that Beggiatoa mats consume dissolved sulfide and oxygen, but a net increase in acidity was only observed in the sediments below. Together, these findings suggest that disproportionation is an important sink for S0 generated by microbial sulfide oxidation in this oxygen-limited system and may contribute to the weathering of carbonate rocks and sediments in sulfur-rich environments.
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Affiliation(s)
- Heidi S Aronson
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Christian E Clark
- Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Douglas E LaRowe
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
| | - Jan P Amend
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
| | - Lubos Polerecky
- Department of Earth Sciences, Utrecht University, Utrecht, The Netherlands
| | - Jennifer L Macalady
- Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania, USA
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2
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Dukes HE, Tinker KA, Ottesen EA. Disentangling hindgut metabolism in the American cockroach through single-cell genomics and metatranscriptomics. Front Microbiol 2023; 14:1156809. [PMID: 37323917 PMCID: PMC10266427 DOI: 10.3389/fmicb.2023.1156809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 05/08/2023] [Indexed: 06/17/2023] Open
Abstract
Omnivorous cockroaches host a complex hindgut microbiota comprised of insect-specific lineages related to those found in mammalian omnivores. Many of these organisms have few cultured representatives, thereby limiting our ability to infer the functional capabilities of these microbes. Here we present a unique reference set of 96 high-quality single cell-amplified genomes (SAGs) from bacterial and archaeal cockroach gut symbionts. We additionally generated cockroach hindgut metagenomic and metatranscriptomic sequence libraries and mapped them to our SAGs. By combining these datasets, we are able to perform an in-depth phylogenetic and functional analysis to evaluate the abundance and activities of the taxa in vivo. Recovered lineages include key genera within Bacteroidota, including polysaccharide-degrading taxa from the genera Bacteroides, Dysgonomonas, and Parabacteroides, as well as a group of unclassified insect-associated Bacteroidales. We also recovered a phylogenetically diverse set of Firmicutes exhibiting a wide range of metabolic capabilities, including-but not limited to-polysaccharide and polypeptide degradation. Other functional groups exhibiting high relative activity in the metatranscriptomic dataset include multiple putative sulfate reducers belonging to families in the Desulfobacterota phylum and two groups of methanogenic archaea. Together, this work provides a valuable reference set with new insights into the functional specializations of insect gut symbionts and frames future studies of cockroach hindgut metabolism.
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Affiliation(s)
- Helen E Dukes
- Department of Microbiology, University of Georgia, Athens, GA, United States
| | - Kara A Tinker
- National Energy Technology Laboratory (NETL), Pittsburgh, PA, United States
| | - Elizabeth A Ottesen
- Department of Microbiology, University of Georgia, Athens, GA, United States
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3
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Alonso-Reyes DG, Galván FS, Irazoqui JM, Amadio A, Tschoeke D, Thompson F, Albarracín VH, Farias ME. Dissecting Light Sensing and Metabolic Pathways on the Millimeter Scale in High-Altitude Modern Stromatolites. MICROBIAL ECOLOGY 2022:10.1007/s00248-022-02112-7. [PMID: 36161499 DOI: 10.1007/s00248-022-02112-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
Modern non-lithifying stromatolites on the shore of the volcanic lake Socompa (SST) in the Puna are affected by several extreme conditions. The present study assesses for the first time light utilization and functional metabolic stratification of SST on a millimeter scale through shotgun metagenomics. In addition, a scanning-electron-microscopy approach was used to explore the community. The analysis on SST unveiled the profile of a photosynthetic mat, with cyanobacteria not directly exposed to light, but placed just below a high-UV-resistant community. Calvin-Benson and 3-hydroxypropinate cycles for carbon fixation were abundant in upper, oxic layers, while the Wood-Ljungdahl pathway was dominant in the deeper anoxic strata. The high abundance of genes for UV-screening and oxidant-quenching pigments and CPF (photoreactivation) in the UV-stressed layers could indicate that the zone itself works as a UV shield. There is a remarkable density of sequences associated with photoreceptors in the first two layers. Also, genetic evidence of photosynthesis split in eukaryotic (layer 1) and prokaryotic (layer 2). Photoheterotrophic bacteria, aerobic photoautotrophic bacteria, and anaerobic photoautotrophic bacteria coexist by selectively absorbing different parts of the light spectrum (blue, red, and IR respectively) at different positions of the mat. Genes for oxygen, nitrogen, and sulfur metabolism account for the microelectrode chemical data and pigment measurements performed in previous publications. We also provide here an explanation for the vertical microbial mobility within the SST described previously. Finally, our study points to SST as ideal modern analogues of ancient ST.
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Affiliation(s)
- Daniel Gonzalo Alonso-Reyes
- Laboratorio de Microbiología Ultraestructural Y Molecular, Centro Integral de Microscopía Electrónica (CIME,), CONICET-Universidad Nacional de Tucumán, Camino de Sirga s/n, Finca El Manantial, Yerba Buena (4107), San Miguel de Tucumán, Tucumán, Argentina
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CCT, CONICET, Tucumán, Argentina
| | - Fátima Silvina Galván
- Laboratorio de Microbiología Ultraestructural Y Molecular, Centro Integral de Microscopía Electrónica (CIME,), CONICET-Universidad Nacional de Tucumán, Camino de Sirga s/n, Finca El Manantial, Yerba Buena (4107), San Miguel de Tucumán, Tucumán, Argentina
| | - José Matías Irazoqui
- Instituto de Investigación de La Cadena Láctea (INTA-CONICET), Rafaela, Argentina
| | - Ariel Amadio
- Instituto de Investigación de La Cadena Láctea (INTA-CONICET), Rafaela, Argentina
| | - Diogo Tschoeke
- Institute of Biology and Coppe, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fabiano Thompson
- Institute of Biology and Coppe, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Virginia Helena Albarracín
- Laboratorio de Microbiología Ultraestructural Y Molecular, Centro Integral de Microscopía Electrónica (CIME,), CONICET-Universidad Nacional de Tucumán, Camino de Sirga s/n, Finca El Manantial, Yerba Buena (4107), San Miguel de Tucumán, Tucumán, Argentina.
- Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, Tucumán, Argentina.
| | - María Eugenia Farias
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CCT, CONICET, Tucumán, Argentina
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4
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Wang Y, Wu G, Zheng X, Mao W, Guan Y. Synergistic ammonia and nitrate removal in a novel pyrite-driven autotrophic denitrification biofilter. BIORESOURCE TECHNOLOGY 2022; 355:127223. [PMID: 35483533 DOI: 10.1016/j.biortech.2022.127223] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/20/2022] [Accepted: 04/21/2022] [Indexed: 06/14/2023]
Abstract
Pyrite is one kind of cost-effective electron donors for nitrate denitrification. In this study, a pyrite-driven autotrophic denitrification biofilter was applied for simultaneous removal of NH4+ and NO3- over the 150-day. The influent NH4+/NO3- ratio (0.3-1.7) had less effect on system performance, while for the hydraulic retention times (HRTs, 24-3 h), the removal percentage of both > 90% and removal loading rates of 52.8 and 59.4 mg N/(L·d) for NH4+ and NO3- removal were obtained at the HRT of 6 h. The 16S rRNA genes analysis showed that Ferritrophicum, Thiobacillus, Candidatus_Brocadia, and unidentified_Nitrospiraceae were predominant. Analyses of nitrogen and sulfur metabolism showed that ammonia was removed by complete nitrification, nitrate was reduced to N2, and sulfide was oxidized to sulfate. Dynamics of pollutants within the reactor and microbial activity showed nitrification/Anammox and pyrite-driven autotrophic denitrification were responsible for the synergistic removal of NH4+/NO3- in this system.
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Affiliation(s)
- Yanfei Wang
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, International Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, PR China; State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Guangxue Wu
- Civil Engineering, School of Engineering, College of Science and Engineering, National University of Ireland, Galway, Galway H91 TK33, Ireland
| | - Xiaona Zheng
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, International Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, PR China; State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Wei Mao
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, International Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, PR China; State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Yuntao Guan
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, International Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, PR China; State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, School of Environment, Tsinghua University, Beijing 100084, PR China.
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5
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Bidaud CC, Monteil CL, Menguy N, Busigny V, Jézéquel D, Viollier É, Travert C, Skouri-Panet F, Benzerara K, Lefevre CT, Duprat É. Biogeochemical Niche of Magnetotactic Cocci Capable of Sequestering Large Polyphosphate Inclusions in the Anoxic Layer of the Lake Pavin Water Column. Front Microbiol 2022; 12:789134. [PMID: 35082768 PMCID: PMC8786505 DOI: 10.3389/fmicb.2021.789134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 11/19/2021] [Indexed: 11/13/2022] Open
Abstract
Magnetotactic bacteria (MTB) are microorganisms thriving mostly at oxic–anoxic boundaries of aquatic habitats. MTB are efficient in biomineralising or sequestering diverse elements intracellularly, which makes them potentially important actors in biogeochemical cycles. Lake Pavin is a unique aqueous system populated by a wide diversity of MTB with two communities harbouring the capability to sequester not only iron under the form of magnetosomes but also phosphorus and magnesium under the form of polyphosphates, or calcium carbonates, respectively. MTB thrive in the water column of Lake Pavin over a few metres along strong redox and chemical gradients representing a series of different microenvironments. In this study, we investigate the relative abundance and the vertical stratification of the diverse populations of MTB in relation to environmental parameters, by using a new method coupling a precise sampling for geochemical analyses, MTB morphotype description, and in situ measurement of the physicochemical parameters. We assess the ultrastructure of MTB as a function of depth using light and electron microscopy. We evidence the biogeochemical niche of magnetotactic cocci, capable of sequestering large PolyP inclusions below the oxic–anoxic transition zone. Our results suggest a tight link between the S and P metabolisms of these bacteria and pave the way to better understand the implication of MTB for the P cycle in stratified environmental conditions.
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Affiliation(s)
- Cécile C Bidaud
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590 - Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Paris, France.,Aix-Marseille University, CNRS, CEA, UMR 7265 Institute of Biosciences and Biotechnologies of Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, France.,Université de Paris, Centre de Recherches Interdisciplinaires (CRI), Paris, France
| | - Caroline L Monteil
- Aix-Marseille University, CNRS, CEA, UMR 7265 Institute of Biosciences and Biotechnologies of Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, France
| | - Nicolas Menguy
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590 - Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Paris, France
| | - Vincent Busigny
- Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France
| | - Didier Jézéquel
- Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France.,INRAE & Université Savoie Mont Blanc, UMR CARRTEL, Thonon-les-Bains, France
| | - Éric Viollier
- LSCE, CEA/CNRS/UVSQ/IPSL, Université Paris Saclay & Université de Paris France, Gif-sur-Yvette Cedex, France
| | - Cynthia Travert
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590 - Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Paris, France
| | - Fériel Skouri-Panet
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590 - Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Paris, France
| | - Karim Benzerara
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590 - Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Paris, France
| | - Christopher T Lefevre
- Aix-Marseille University, CNRS, CEA, UMR 7265 Institute of Biosciences and Biotechnologies of Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, France
| | - Élodie Duprat
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590 - Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Paris, France
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6
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Patwardhan S, Smedile F, Giovannelli D, Vetriani C. Metaproteogenomic Profiling of Chemosynthetic Microbial Biofilms Reveals Metabolic Flexibility During Colonization of a Shallow-Water Gas Vent. Front Microbiol 2021; 12:638300. [PMID: 33889140 PMCID: PMC8056087 DOI: 10.3389/fmicb.2021.638300] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 03/02/2021] [Indexed: 11/13/2022] Open
Abstract
Tor Caldara is a shallow-water gas vent located in the Mediterranean Sea, with active venting of CO2 and H2S. At Tor Caldara, filamentous microbial biofilms, mainly composed of Epsilon- and Gammaproteobacteria, grow on substrates exposed to the gas venting. In this study, we took a metaproteogenomic approach to identify the metabolic potential and in situ expression of central metabolic pathways at two stages of biofilm maturation. Our findings indicate that inorganic reduced sulfur species are the main electron donors and CO2 the main carbon source for the filamentous biofilms, which conserve energy by oxygen and nitrate respiration, fix dinitrogen gas and detoxify heavy metals. Three metagenome-assembled genomes (MAGs), representative of key members in the biofilm community, were also recovered. Metaproteomic data show that metabolically active chemoautotrophic sulfide-oxidizing members of the Epsilonproteobacteria dominated the young microbial biofilms, while Gammaproteobacteria become prevalent in the established community. The co-expression of different pathways for sulfide oxidation by these two classes of bacteria suggests exposure to different sulfide concentrations within the biofilms, as well as fine-tuned adaptations of the enzymatic complexes. Taken together, our findings demonstrate a shift in the taxonomic composition and associated metabolic activity of these biofilms in the course of the colonization process.
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Affiliation(s)
- Sushmita Patwardhan
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, United States
| | - Francesco Smedile
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, United States.,National Research Council, Institute for Coastal Marine Environment, Messina, Italy
| | - Donato Giovannelli
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, United States.,Department of Biology, University of Naples "Federico II," Naples, Italy.,National Research Council, Institute for Marine Biological and Biotechnological Resources, Ancona, Italy.,Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
| | - Costantino Vetriani
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, United States.,Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, United States
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7
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Wang L, Shao Z. Aerobic Denitrification and Heterotrophic Sulfur Oxidation in the Genus Halomonas Revealed by Six Novel Species Characterizations and Genome-Based Analysis. Front Microbiol 2021; 12:652766. [PMID: 33815342 PMCID: PMC8014003 DOI: 10.3389/fmicb.2021.652766] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/09/2021] [Indexed: 11/16/2022] Open
Abstract
Bacteria of Halomonas are widely distributed in various environments and play a substantial role in the nutrient cycle. In this report, 14 strains capable of aerobic denitrification and heterotrophic sulfur oxidation were isolated from different habitats. Based on the phenotypic, genotypic, and chemotaxonomic analyses, these strains were considered to represent six novel species of the genus Halomonas, for which the names Halomonas zhangzhouensis sp. nov. type strain CXT3-11T ( = MCCC 1A11036T = KCTC 72087T), Halomonas aerodenitrificans sp. nov. CYD-9T ( = MCCC 1A11058T = KCTC 72088T), Halomonas sulfidoxydans sp. nov. CYN-1-2T ( = MCCC 1A11059T = KCTC 72089T), Halomonas ethanolica sp. nov. CYT3-1-1T ( = MCCC 1A11081T = KCTC 72090T), Halomonas sulfidivorans sp. nov. NLG_F1ET ( = MCCC 1A13718T = KCTC 72091T), and Halomonas tianxiuensis sp. nov. BC-M4-5T ( = MCCC 1A14433T = KCTC 72092T) are proposed. Intriguingly, they formed a unique group with 11 other species designated as the "H. desiderata group." To better understand their featured metabolisms, genes involved in denitrification and sulfur oxidation were analyzed, along with 193 other available genomes of the whole genus. Consistently, complete denitrification pathways were confirmed in the "H. desiderata group," in which napA, narG, nirS, norB, and nosZ genes coexist. Their nitrite reductase NirS formed a unique evolutionary lineage, distinguished from other denitrifiers in Halomonas. In addition, diverse occurrence patterns of denitrification genes were also observed in different phylogenetic clades of Halomonas. With respect to sulfur oxidation, fccAB genes involved in sulfide oxidation commonly exist in the "H. desiderata group," while sqr genes are diverse and can be found in more species; sqr genes co-occurred with fccAB in eight strains of this study, contributing to more active sulfide oxidation. Besides, the tsdA gene, which encodes an enzyme that oxidizes thiosulfate to tetrathionate, is ubiquitous in the genus Halomonas. The widespread presence of sqr/fccAB, pdo, and tsdA in Halomonas suggests that many Halomonas spp. can act as heterotrophic sulfur oxidizers. These results provide comprehensive insights into the potential of denitrification and sulfur oxidation in the whole genus of Halomonas. With regard to the global distribution of Halomonas, this report implies their unneglectable role in the biogeochemical cycle.
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Affiliation(s)
- Liping Wang
- School of Environment, Harbin Institute of Technology, Harbin, China
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen, China
| | - Zongze Shao
- School of Environment, Harbin Institute of Technology, Harbin, China
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
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8
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Ionescu D, Zoccarato L, Zaduryan A, Schorn S, Bizic M, Pinnow S, Cypionka H, Grossart HP. Heterozygous, Polyploid, Giant Bacterium, Achromatium, Possesses an Identical Functional Inventory Worldwide across Drastically Different Ecosystems. Mol Biol Evol 2021; 38:1040-1059. [PMID: 33169788 PMCID: PMC7947748 DOI: 10.1093/molbev/msaa273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Achromatium is large, hyperpolyploid and the only known heterozygous bacterium. Single cells contain approximately 300 different chromosomes with allelic diversity far exceeding that typically harbored by single bacteria genera. Surveying all publicly available sediment sequence archives, we show that Achromatium is common worldwide, spanning temperature, salinity, pH, and depth ranges normally resulting in bacterial speciation. Although saline and freshwater Achromatium spp. appear phylogenetically separated, the genus Achromatium contains a globally identical, complete functional inventory regardless of habitat. Achromatium spp. cells from differing ecosystems (e.g., from freshwater to saline) are, unexpectedly, equally functionally equipped but differ in gene expression patterns by transcribing only relevant genes. We suggest that environmental adaptation occurs by increasing the copy number of relevant genes across the cell's hundreds of chromosomes, without losing irrelevant ones, thus maintaining the ability to survive in any ecosystem type. The functional versatility of Achromatium and its genomic features reveal alternative genetic and evolutionary mechanisms, expanding our understanding of the role and evolution of polyploidy in bacteria while challenging the bacterial species concept and drivers of bacterial speciation.
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Affiliation(s)
- Danny Ionescu
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Neuglobsow, Germany
- Berlin Brandenburg Institute of Biodiversity, Berlin, Germany
| | - Luca Zoccarato
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Neuglobsow, Germany
| | - Artur Zaduryan
- Department of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Sina Schorn
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Mina Bizic
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Neuglobsow, Germany
- Berlin Brandenburg Institute of Biodiversity, Berlin, Germany
| | - Solvig Pinnow
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Neuglobsow, Germany
| | - Heribert Cypionka
- Institute for Chemistry and Biology of the Marine Environment, Oldenburg, Germany
| | - Hans-Peter Grossart
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Neuglobsow, Germany
- Berlin Brandenburg Institute of Biodiversity, Berlin, Germany
- Institute of Biochemistry and Biology, Potsdam University, Potsdam, Germany
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9
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Merz E, Dick GJ, de Beer D, Grim S, Hübener T, Littmann S, Olsen K, Stuart D, Lavik G, Marchant HK, Klatt JM. Nitrate respiration and diel migration patterns of diatoms are linked in sediments underneath a microbial mat. Environ Microbiol 2020; 23:1422-1435. [PMID: 33264477 DOI: 10.1111/1462-2920.15345] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/23/2020] [Accepted: 11/30/2020] [Indexed: 12/12/2022]
Abstract
Diatoms are among the few eukaryotes known to store nitrate (NO3 - ) and to use it as an electron acceptor for respiration in the absence of light and O2 . Using microscopy and 15 N stable isotope incubations, we studied the relationship between dissimilatory nitrate/nitrite reduction to ammonium (DNRA) and diel vertical migration of diatoms in phototrophic microbial mats and the underlying sediment of a sinkhole in Lake Huron (USA). We found that the diatoms rapidly accumulated NO3 - at the mat-water interface in the afternoon and 40% of the population migrated deep into the sediment, where they were exposed to dark and anoxic conditions for ~75% of the day. The vertical distribution of DNRA rates and diatom abundance maxima coincided, suggesting that DNRA was the main energy generating metabolism of the diatom population. We conclude that the illuminated redox-dynamic ecosystem selects for migratory diatoms that can store nitrate for respiration in the absence of light. A major implication of this study is that the dominance of DNRA over denitrification is not explained by kinetics or thermodynamics. Rather, the dynamic conditions select for migratory diatoms that perform DNRA and can outcompete sessile denitrifiers.
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Affiliation(s)
- Elisa Merz
- Max Planck Institute for Marine Microbiology, Celsiusstr. 1, Bremen, Germany
| | - Gregory J Dick
- Geomicrobiology Lab, Department of Earth & Environmental Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Dirk de Beer
- Max Planck Institute for Marine Microbiology, Celsiusstr. 1, Bremen, Germany
| | - Sharon Grim
- Geomicrobiology Lab, Department of Earth & Environmental Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Thomas Hübener
- Department of Botany and Botanical Garden, University of Rostock, Institute of Biosciences, Germany
| | - Sten Littmann
- Max Planck Institute for Marine Microbiology, Celsiusstr. 1, Bremen, Germany
| | - Kirk Olsen
- Geomicrobiology Lab, Department of Earth & Environmental Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Dack Stuart
- University of Michigan, Cooperative Institute for Great Lakes Research, Ann Arbor, Michigan, USA
| | - Gaute Lavik
- Max Planck Institute for Marine Microbiology, Celsiusstr. 1, Bremen, Germany
| | - Hannah K Marchant
- Max Planck Institute for Marine Microbiology, Celsiusstr. 1, Bremen, Germany
| | - Judith M Klatt
- Max Planck Institute for Marine Microbiology, Celsiusstr. 1, Bremen, Germany.,Geomicrobiology Lab, Department of Earth & Environmental Sciences, University of Michigan, Ann Arbor, Michigan, USA
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10
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Tan JY, Wang S, Dick GJ, Young VB, Sherman DH, Burns MA, Lin XN. Co-cultivation of microbial sub-communities in microfluidic droplets facilitates high-resolution genomic dissection of microbial 'dark matter'. Integr Biol (Camb) 2020; 12:263-274. [PMID: 33089329 PMCID: PMC7671993 DOI: 10.1093/intbio/zyaa021] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 08/05/2020] [Accepted: 09/22/2020] [Indexed: 12/19/2022]
Abstract
While the 'unculturable' majority of the bacterial world is accessible with culture-independent tools, the inability to study these bacteria using culture-dependent approaches has severely limited our understanding of their ecological roles and interactions. To circumvent cultivation barriers, we utilize microfluidic droplets as localized, nanoliter-size bioreactors to co-cultivate subsets of microbial communities. This co-localization can support ecological interactions between a reduced number of encapsulated cells. We demonstrated the utility of this approach in the encapsulation and co-cultivation of droplet sub-communities from a fecal sample collected from a healthy human subject. With the whole genome amplification and metagenomic shotgun sequencing of co-cultivated sub-communities from 22 droplets, we observed that this approach provides accessibility to uncharacterized gut commensals for study. The recovery of metagenome-assembled genomes from one droplet sub-community demonstrated the capability to dissect the sub-communities with high-genomic resolution. In particular, genomic characterization of one novel member of the family Neisseriaceae revealed implications regarding its participation in fatty acid degradation and production of atherogenic intermediates in the human gut. The demonstrated genomic resolution and accessibility to the microbial 'dark matter' with this methodology can be applied to study the interactions of rare or previously uncultivated members of microbial communities.
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Affiliation(s)
- James Y Tan
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Sida Wang
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Gregory J Dick
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Vincent B Young
- Deparment of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
- Infectious Diseases Division, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - David H Sherman
- Deparment of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI, USA
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Mark A Burns
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Xiaoxia N Lin
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
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11
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Pandey CB, Kumar U, Kaviraj M, Minick KJ, Mishra AK, Singh JS. DNRA: A short-circuit in biological N-cycling to conserve nitrogen in terrestrial ecosystems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 738:139710. [PMID: 32544704 DOI: 10.1016/j.scitotenv.2020.139710] [Citation(s) in RCA: 106] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 05/21/2020] [Accepted: 05/23/2020] [Indexed: 06/11/2023]
Abstract
This paper reviews dissimilatory nitrate reduction to ammonium (DNRA) in soils - a newly appreciated pathway of nitrogen (N) cycling in the terrestrial ecosystems. The reduction of NO3- occurs in two steps; in the first step, NO3- is reduced to NO2-; and in the second, unlike denitrification, NO2- is reduced to NH4+ without intermediates. There are two sets of NO3-/NO2- reductase enzymes, i.e., Nap/Nrf and Nar/Nir; the former occurs on the periplasmic-membrane and energy conservation is respiratory via electron-transport-chain, whereas the latter is cytoplasmic and energy conservation is both respiratory and fermentative (Nir, substrate-phosphorylation). Since, Nir catalyzes both assimilatory- and dissimilatory-nitrate reduction, the nrfA gene, which transcribes the NrfA protein, is treated as a molecular-marker of DNRA; and a high nrfA/nosZ (N2O-reductase) ratio favours DNRA. Recently, several crystal structures of NrfA have been presumed to producee N2O as a byproduct of DNRA via the NO (nitric-oxide) pathway. Meta-analyses of about 200 publications have revealed that DNRA is regulated by oxidation state of soils and sediments, carbon (C)/N and NO2-/NO3- ratio, and concentrations of ferrous iron (Fe2+) and sulfide (S2-). Under low-redox conditions, a high C/NO3- ratio selects for DNRA while a low ratio selects for denitrification. When the proportion of both C and NO3- are equal, the NO2-/NO3- ratio modulates partitioning of NO3-, and a high NO2-/NO3- ratio favours DNRA. A high S2-/NO3- ratio also promotes DNRA in coastal-ecosystems and saline sediments. Soil pH, temperature, and fine soil particles are other factors known to influence DNRA. Since, DNRA reduces NO3- to NH4+, it is essential for protecting NO3- from leaching and gaseous (N2O) losses and enriches soils with readily available NH4+-N to primary producers and heterotrophic microorganisms. Therefore, DNRA may be treated as a tool to reduce ground-water NO3- pollution, enhance soil health and improve environmental quality.
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Affiliation(s)
- C B Pandey
- ICAR-Central Arid Zone Research Institute, Jodhpur 342003, Rajasthan, India.
| | - Upendra Kumar
- ICAR-National Rice Research Institute, Cuttack 753006, Odisha, India.
| | - Megha Kaviraj
- ICAR-National Rice Research Institute, Cuttack 753006, Odisha, India
| | - K J Minick
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27695, USA
| | - A K Mishra
- International Rice Research Institute, New Delhi 110012, India
| | - J S Singh
- Ecosystem Analysis Lab, Centre of Advanced Study in Botany, Banaras Hindu University (BHU), Varanasi 221005, India
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12
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Schorn S, Salman-Carvalho V, Littmann S, Ionescu D, Grossart HP, Cypionka H. Cell Architecture of the Giant Sulfur Bacterium Achromatium oxaliferum: Extra-cytoplasmic Localization of Calcium Carbonate Bodies. FEMS Microbiol Ecol 2020; 96:5686722. [PMID: 31873729 PMCID: PMC6995342 DOI: 10.1093/femsec/fiz200] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 12/16/2019] [Indexed: 11/19/2022] Open
Abstract
Achromatium oxaliferum is a large sulfur bacterium easily recognized by large intracellular calcium carbonate bodies. Although these bodies often fill major parts of the cells’ volume, their role and specific intracellular location are unclear. In this study, we used various microscopy and staining techniques to identify the cell compartment harboring the calcium carbonate bodies. We observed that Achromatium cells often lost their calcium carbonate bodies, either naturally or induced by treatments with diluted acids, ethanol, sodium bicarbonate and UV radiation which did not visibly affect the overall shape and motility of the cells (except for UV radiation). The water-soluble fluorescent dye fluorescein easily diffused into empty cavities remaining after calcium carbonate loss. Membranes (stained with Nile Red) formed a network stretching throughout the cell and surrounding empty or filled calcium carbonate cavities. The cytoplasm (stained with FITC and SYBR Green for nucleic acids) appeared highly condensed and showed spots of dissolved Ca2+ (stained with Fura-2). From our observations, we conclude that the calcium carbonate bodies are located in the periplasm, in extra-cytoplasmic pockets of the cytoplasmic membrane and are thus kept separate from the cell's cytoplasm. This periplasmic localization of the carbonate bodies might explain their dynamic formation and release upon environmental changes.
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Affiliation(s)
- Sina Schorn
- Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359 Bremen, Bremen, Germany.,Institute for Chemistry and Biology of the Marine Environment, Carl-von-Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 911, 26133 Oldenburg, Oldenburg, Germany
| | - Verena Salman-Carvalho
- Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359 Bremen, Bremen, Germany
| | - Sten Littmann
- Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359 Bremen, Bremen, Germany
| | - Danny Ionescu
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Alte Fischerhütte 2, 16775 Stechlin, Berlin, Germany
| | - Hans-Peter Grossart
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Alte Fischerhütte 2, 16775 Stechlin, Berlin, Germany.,Institute of Biochemistry and Biology, Potsdam University, Karl-Liebknecht Straße 24-25, 14476 Potsdam, Potsdam, Germany
| | - Heribert Cypionka
- Institute for Chemistry and Biology of the Marine Environment, Carl-von-Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 911, 26133 Oldenburg, Oldenburg, Germany
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13
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Zhang J, Liu R, Xi S, Cai R, Zhang X, Sun C. A novel bacterial thiosulfate oxidation pathway provides a new clue about the formation of zero-valent sulfur in deep sea. ISME JOURNAL 2020; 14:2261-2274. [PMID: 32457501 PMCID: PMC7608252 DOI: 10.1038/s41396-020-0684-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 05/06/2020] [Accepted: 05/12/2020] [Indexed: 11/09/2022]
Abstract
Zero-valent sulfur (ZVS) has been shown to be a major sulfur intermediate in the deep-sea cold seep of the South China Sea based on our previous work, however, the microbial contribution to the formation of ZVS in cold seep has remained unclear. Here, we describe a novel thiosulfate oxidation pathway discovered in the deep-sea cold seep bacterium Erythrobacter flavus 21–3, which provides a new clue about the formation of ZVS. Electronic microscopy, energy-dispersive, and Raman spectra were used to confirm that E. flavus 21–3 effectively converts thiosulfate to ZVS. We next used a combined proteomic and genetic method to identify thiosulfate dehydrogenase (TsdA) and thiosulfohydrolase (SoxB) playing key roles in the conversion of thiosulfate to ZVS. Stoichiometric results of different sulfur intermediates further clarify the function of TsdA in converting thiosulfate to tetrathionate (−O3S–S–S–SO3−), SoxB in liberating sulfone from tetrathionate to form ZVS and sulfur dioxygenases (SdoA/SdoB) in oxidizing ZVS to sulfite under some conditions. Notably, homologs of TsdA, SoxB, and SdoA/SdoB widely exist across the bacteria including in Erythrobacter species derived from different environments. This strongly indicates that this novel thiosulfate oxidation pathway might be frequently used by microbes and plays an important role in the biogeochemical sulfur cycle in nature.
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Affiliation(s)
- Jing Zhang
- CAS Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,College of Earth Science, University of Chinese Academy of Sciences, Beijing, China.,Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Rui Liu
- CAS Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Shichuan Xi
- College of Earth Science, University of Chinese Academy of Sciences, Beijing, China.,Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China.,CAS Key Laboratory of Marine Geology and Environment & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Ruining Cai
- CAS Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,College of Earth Science, University of Chinese Academy of Sciences, Beijing, China.,Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Xin Zhang
- Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China.,CAS Key Laboratory of Marine Geology and Environment & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Chaomin Sun
- CAS Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China. .,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China. .,Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China.
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14
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Dorofeev AG, Nikolaev YA, Mardanov AV, Pimenov NV. Cyclic Metabolism as a Mode of Microbial Existence. Microbiology (Reading) 2019. [DOI: 10.1134/s0026261719040052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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15
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Sam Kamaleson A, Gonsalves MJ, Nazareth DR. Interactions of sulfur and methane-oxidizing bacteria in tropical estuarine sediments. ENVIRONMENTAL MONITORING AND ASSESSMENT 2019; 191:496. [PMID: 31312943 DOI: 10.1007/s10661-019-7616-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 06/24/2019] [Indexed: 06/10/2023]
Abstract
The bacterial oxidation of sulfur and methane is central to the biogeochemical processes in sediments such as the tropical mangrove sediments. However, there is a lacuna of information on the seasonal interactions including the influence of monsoons which is a major driver of seasonal change, on sulfur-oxidizing bacteria (SOB) and methane-oxidizing bacteria (MOB), their activity and the environmental variables. To understand these interactions, the analysis was carried out on sediment samples that were sampled monthly for a year from Chorao mangrove, Goa, southwest coast of India. SOB (3.8×105CFU g-1) and MOB (0.90×105CFU g-1) had maximum average abundance in the surface sediments in the post-monsoon and monsoon season, respectively. The mean sulfur-oxidation activity (SOA) of 2.63 mM day-1 and methane-oxidation activity (MOA) of 110.94 mM day-1 were highest in surface sediments during the post-monsoon season. Generally, the activity of SOB and MOB in surface sediments of post-monsoon was 2.2 times(×) and 2.8× respectively higher than that in the monsoon season. Among the environmental parameters analyzed, protein and sulfide concentrations significantly (p < 0.001) influenced SOA and MOA, respectively. There was a significant difference in SOA (p < 0.003) and MOA (p < 0.036) in surface sediments between the monsoon and the post-monsoon season. During the monsoon season, when the system is a sink of terrestrial/anthropogenic material, the interrelationship of SOB with MOA (r = 0.617, p < 0.001) and SOB with SOA (r = 0.489, p < 0.05) aids in maintaining the homeostasis of the system.
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Affiliation(s)
- A Sam Kamaleson
- CSIR-National Institute of Oceanography, Dona Paula, Goa, 403004, India
- Bharathidasan University, Tiruchirappalli, Tamil Nadu, India
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16
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Watanabe M, Kojima H, Umezawa K, Fukui M. Genomic Characteristics of Desulfonema ishimotonii Tokyo 01 T Implying Horizontal Gene Transfer Among Phylogenetically Dispersed Filamentous Gliding Bacteria. Front Microbiol 2019; 10:227. [PMID: 30837965 PMCID: PMC6390638 DOI: 10.3389/fmicb.2019.00227] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 01/28/2019] [Indexed: 11/13/2022] Open
Abstract
Desulfonema ishimotonii strain Tokyo 01T is a filamentous sulfate-reducing bacterium isolated from a marine sediment. In this study, the genome of this strain was sequenced and analyzed with a focus on gene transfer from phylogenetically distant organisms. While the strain belongs to the class Deltaproteobacteria, hundreds of proteins encoded in the genome showed the highest sequence similarities to those of organisms outside of the class Deltaproteobacteria, suggesting that more than 20% of the genome is putatively of foreign origins. Many of these proteins had the highest sequence identities with proteins encoded in the genomes of filamentous bacteria, including giant sulfur oxidizers of the orders Thiotrichales, cyanobacteria of various genera, and uncultured bacteria of the candidate phylum KSB3. As mobile genetic elements transferred from phylogenetically distant organisms, putative inteins were identified in the GyrB and DnaE proteins encoded in the genome of strain Tokyo 01T. Genes involved in DNA recombination and repair were enriched in comparison to the closest relatives in the same family. Some of these genes were also related to those of organisms outside of the class Deltaproteobacteria, suggesting that they were acquired by horizontal gene transfer from diverse bacteria. The genomic data suggested significant genetic transfer among filamentous gliding bacteria in phylogenetically dispersed lineages including filamentous sulfate reducers. This study provides insights into the genomic evolution of filamentous bacteria belonging to diverse lineages, characterized by various physiological functions and different ecological roles.
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Affiliation(s)
- Miho Watanabe
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan.,Japan Society for the Promotion of Science, Tokyo, Japan
| | - Hisaya Kojima
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
| | - Kazuhiro Umezawa
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
| | - Manabu Fukui
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
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17
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Filamentous Giant Beggiatoaceae from the Guaymas Basin Are Capable of both Denitrification and Dissimilatory Nitrate Reduction to Ammonium. Appl Environ Microbiol 2018; 84:AEM.02860-17. [PMID: 29802192 PMCID: PMC6052272 DOI: 10.1128/aem.02860-17] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Accepted: 05/14/2018] [Indexed: 01/31/2023] Open
Abstract
Whether large sulfur bacteria of the family Beggiatoaceae reduce NO3− to N2 via denitrification or to NH4+ via DNRA has been debated in the literature for more than 25 years. We resolve this debate by showing that certain members of the Beggiatoaceae use both metabolic pathways. This is important for the ecological role of these bacteria, as N2 production removes bioavailable nitrogen from the ecosystem, whereas NH4+ production retains it. For this reason, the topic of environmental controls on the competition for NO3− between N2-producing and NH4+-producing bacteria is of great scientific interest. Recent experiments on the competition between these two types of microorganisms have demonstrated that the balance between electron donor and electron acceptor availability strongly influences the end product of NO3− reduction. Our results suggest that this is also the case at the even more fundamental level of enzyme system regulation within a single organism. Filamentous large sulfur-oxidizing bacteria (FLSB) of the family Beggiatoaceae are globally distributed aquatic bacteria that can control geochemical fluxes from the sediment to the water column through their metabolic activity. FLSB mats from hydrothermal sediments of Guaymas Basin, Mexico, typically have a “fried-egg” appearance, with orange filaments dominating near the center and wider white filaments at the periphery, likely reflecting areas of higher and lower sulfide fluxes, respectively. These FLSB store large quantities of intracellular nitrate that they use to oxidize sulfide. By applying a combination of 15N-labeling techniques and genome sequence analysis, we demonstrate that the white FLSB filaments were capable of reducing their intracellular nitrate stores to both nitrogen gas and ammonium by denitrification and dissimilatory nitrate reduction to ammonium (DNRA), respectively. On the other hand, our combined results show that the orange filaments were primarily capable of DNRA. Microsensor profiles through a laboratory-incubated white FLSB mat revealed a 2- to 3-mm vertical separation between the oxic and sulfidic zones. Denitrification was most intense just below the oxic zone, as shown by the production of nitrous oxide following exposure to acetylene, which blocks nitrous oxide reduction to nitrogen gas. Below this zone, a local pH maximum coincided with sulfide oxidation, consistent with nitrate reduction by DNRA. The balance between internally and externally available electron acceptors (nitrate) and electron donors (reduced sulfur) likely controlled the end product of nitrate reduction both between orange and white FLSB mats and between different spatial and geochemical niches within the white FLSB mat. IMPORTANCE Whether large sulfur bacteria of the family Beggiatoaceae reduce NO3− to N2 via denitrification or to NH4+ via DNRA has been debated in the literature for more than 25 years. We resolve this debate by showing that certain members of the Beggiatoaceae use both metabolic pathways. This is important for the ecological role of these bacteria, as N2 production removes bioavailable nitrogen from the ecosystem, whereas NH4+ production retains it. For this reason, the topic of environmental controls on the competition for NO3− between N2-producing and NH4+-producing bacteria is of great scientific interest. Recent experiments on the competition between these two types of microorganisms have demonstrated that the balance between electron donor and electron acceptor availability strongly influences the end product of NO3− reduction. Our results suggest that this is also the case at the even more fundamental level of enzyme system regulation within a single organism.
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18
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Fonseca A, Ishoey T, Espinoza C, Pérez-Pantoja D, Manghisi A, Morabito M, Salas-Burgos A, Gallardo VA. Genomic features of "Candidatus Venteria ishoeyi", a new sulfur-oxidizing macrobacterium from the Humboldt Sulfuretum off Chile. PLoS One 2017; 12:e0188371. [PMID: 29236755 PMCID: PMC5728499 DOI: 10.1371/journal.pone.0188371] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Accepted: 11/06/2017] [Indexed: 12/13/2022] Open
Abstract
The Humboldt Sulfuretum (HS), in the productive Humboldt Eastern Boundary Current Upwelling Ecosystem, extends under the hypoxic waters of the Peru-Chile Undercurrent (ca. 6°S and ca. 36°S). Studies show that primeval sulfuretums held diverse prokaryotic life, and, while rare today, still sustain species-rich giant sulfur-oxidizing bacterial communities. We here present the genomic features of a new bacteria of the HS, "Candidatus Venteria ishoeyi" ("Ca. V. ishoeyi") in the family Thiotrichaceae.Three identical filaments were micro-manipulated from reduced sediments collected off central Chile; their DNA was extracted, amplified, and sequenced by a Roche 454 GS FLX platform. Using three sequenced libraries and through de novo genome assembly, a draft genome of 5.7 Mbp, 495 scaffolds, and a N50 of 70 kbp, was obtained. The 16S rRNA gene phylogenetic analysis showed that "Ca. V. ishoeyi" is related to non-vacuolate forms presently known as Beggiatoa or Beggiatoa-like forms. The complete set of genes involved in respiratory nitrate-reduction to dinitrogen was identified in "Ca. V. ishoeyi"; including genes likely leading to ammonification. As expected, the sulfur-oxidation pathway reported for other sulfur-oxidizing bacteria were deduced and also, key inorganic and organic carbon acquisition related genes were identified. Unexpectedly, the genome of "Ca. V. ishoeyi" contained numerous CRISPR repeats and an I-F CRISPR-Cas type system gene coding array. Findings further show that, as a member of an eons-old marine ecosystem, "Ca. V. ishoeyi" contains the needed metabolic plasticity for life in an increasingly oxygenated and variable ocean.
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Affiliation(s)
- Alexis Fonseca
- Department of Pharmacology, University of Concepcion, Concepcion, Chile
- Department of Oceanography, University of Concepcion, Concepcion, Chile
| | - Thomas Ishoey
- Independent consultant, Encinitas, California, United States of America
| | - Carola Espinoza
- Department of Oceanography, University of Concepcion, Concepcion, Chile
- College of Ocean Science and Resources, Institute Marine Affairs and Resource Management, National Taiwan Ocean University, Keelung, Taiwan
| | - Danilo Pérez-Pantoja
- Programa Institucional de Fomento a la Investigación, Desarrollo e Innovación, Universidad Tecnológica Metropolitana, San Joaquin, Santiago, Chile
| | - Antonio Manghisi
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Marina Morabito
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | | | - Víctor A. Gallardo
- Department of Oceanography, University of Concepcion, Concepcion, Chile
- College of Ocean Science and Resources, Institute Marine Affairs and Resource Management, National Taiwan Ocean University, Keelung, Taiwan
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19
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Abstract
The largest known bacteria, Thiomargarita spp., have yet to be isolated in pure culture, but their large size allows for individual cells to be monitored in time course experiments or to be individually sorted for omics-based investigations. Here we investigated the metabolism of individual cells of Thiomargarita spp. by using a novel application of a tetrazolium-based dye that measures oxidoreductase activity. When coupled with microscopy, staining of the cells with a tetrazolium-formazan dye allows metabolic responses in Thiomargarita spp. to be to be tracked in the absence of observable cell division. Additionally, the metabolic activity of Thiomargarita sp. cells can be differentiated from the metabolism of other microbes in specimens that contain adherent bacteria. The results of our redox dye-based assay suggest that Thiomargarita is the most metabolically versatile under anoxic conditions, where it appears to express cellular oxidoreductase activity in response to the electron donors succinate, acetate, citrate, formate, thiosulfate, H2, and H2S. Under hypoxic conditions, formazan staining results suggest the metabolism of succinate and likely acetate, citrate, and H2S. Cells incubated under oxic conditions showed the weakest formazan staining response, and then only to H2S, citrate, and perhaps succinate. These results provide experimental validation of recent genomic studies of Candidatus Thiomargarita nelsonii that suggest metabolic plasticity and mixotrophic metabolism. The cellular oxidoreductase response of bacteria attached to the exterior of Thiomargarita also supports the possibility of trophic interactions between these largest of known bacteria and attached epibionts. The metabolic potential of many microorganisms that cannot be grown in the laboratory is known only from genomic data. Genomes of Thiomargarita spp. suggest that these largest of known bacteria are mixotrophs, combining lithotrophic metabolism with organic carbon degradation. Our use of a redox-sensitive tetrazolium dye to query the metabolism of these bacteria provides an independent line of evidence that corroborates the apparent metabolic plasticity of Thiomargarita observed in recently produced genomes. Finding new cultivation-independent means of testing genomic results is critical to testing genome-derived hypotheses on the metabolic potentials of uncultivated microorganisms.
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20
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Sharrar AM, Flood BE, Bailey JV, Jones DS, Biddanda BA, Ruberg SA, Marcus DN, Dick GJ. Novel Large Sulfur Bacteria in the Metagenomes of Groundwater-Fed Chemosynthetic Microbial Mats in the Lake Huron Basin. Front Microbiol 2017; 8:791. [PMID: 28533768 PMCID: PMC5421297 DOI: 10.3389/fmicb.2017.00791] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 04/18/2017] [Indexed: 11/25/2022] Open
Abstract
Little is known about large sulfur bacteria (LSB) that inhabit sulfidic groundwater seeps in large lakes. To examine how geochemically relevant microbial metabolisms are partitioned among community members, we conducted metagenomic analysis of a chemosynthetic microbial mat in the Isolated Sinkhole, which is in a deep, aphotic environment of Lake Huron. For comparison, we also analyzed a white mat in an artesian fountain that is fed by groundwater similar to Isolated Sinkhole, but that sits in shallow water and is exposed to sunlight. De novo assembly and binning of metagenomic data from these two communities yielded near complete genomes and revealed representatives of two families of LSB. The Isolated Sinkhole community was dominated by novel members of the Beggiatoaceae that are phylogenetically intermediate between known freshwater and marine groups. Several of these Beggiatoaceae had 16S rRNA genes that contained introns previously observed only in marine taxa. The Alpena fountain was dominated by populations closely related to Thiothrix lacustris and an SM1 euryarchaeon known to live symbiotically with Thiothrix spp. The SM1 genomic bin contained evidence of H2-based lithoautotrophy. Genomic bins of both the Thiothrix and Beggiatoaceae contained genes for sulfur oxidation via the rDsr pathway, H2 oxidation via Ni-Fe hydrogenases, and the use of O2 and nitrate as electron acceptors. Mats at both sites also contained Deltaproteobacteria with genes for dissimilatory sulfate reduction (sat, apr, and dsr) and hydrogen oxidation (Ni-Fe hydrogenases). Overall, the microbial mats at the two sites held low-diversity microbial communities, displayed evidence of coupled sulfur cycling, and did not differ largely in their metabolic potentials, despite the environmental differences. These results show that groundwater-fed communities in an artesian fountain and in submerged sinkholes of Lake Huron are a rich source of novel LSB, associated heterotrophic and sulfate-reducing bacteria, and archaea.
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Affiliation(s)
- Allison M Sharrar
- Department of Earth and Environmental Sciences, University of Michigan, Ann ArborMI, USA
| | - Beverly E Flood
- Department of Earth Sciences, University of Minnesota, MinneapolisMN, USA
| | - Jake V Bailey
- Department of Earth Sciences, University of Minnesota, MinneapolisMN, USA
| | - Daniel S Jones
- Department of Earth Sciences, University of Minnesota, MinneapolisMN, USA.,BioTechnology Institute, University of Minnesota, MinneapolisMN, USA
| | - Bopaiah A Biddanda
- Annis Water Resources Institute, Grand Valley State University, MuskegonMI, USA
| | - Steven A Ruberg
- NOAA-Great Lakes Environmental Research Laboratory, Ann ArborMI, USA
| | - Daniel N Marcus
- Department of Earth and Environmental Sciences, University of Michigan, Ann ArborMI, USA
| | - Gregory J Dick
- Department of Earth and Environmental Sciences, University of Michigan, Ann ArborMI, USA
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21
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Reyes C, Schneider D, Lipka M, Thürmer A, Böttcher ME, Friedrich MW. Nitrogen Metabolism Genes from Temperate Marine Sediments. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2017; 19:175-190. [PMID: 28283802 PMCID: PMC5405112 DOI: 10.1007/s10126-017-9741-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 02/05/2017] [Indexed: 05/26/2023]
Abstract
In this study, we analysed metagenomes along with biogeochemical profiles from Skagerrak (SK) and Bothnian Bay (BB) sediments, to trace the prevailing nitrogen pathways. NO3- was present in the top 5 cm below the sediment-water interface at both sites. NH4+ increased with depth below 5 cm where it overlapped with the NO3- zone. Steady-state modelling of NO3- and NH4+ porewater profiles indicates zones of net nitrogen species transformations. Bacterial protease and hydratase genes appeared to make up the bulk of total ammonification genes. Genes involved in ammonia oxidation (amo, hao), denitrification (nir, nor), dissimilatory NO3- reduction to NH4+ (nfr and otr) and in both of the latter two pathways (nar, nap) were also present. Results show ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) are similarly abundant in both sediments. Also, denitrification genes appeared more abundant than DNRA genes. 16S rRNA gene analysis showed that the relative abundance of the nitrifying group Nitrosopumilales and other groups involved in nitrification and denitrification (Nitrobacter, Nitrosomonas, Nitrospira, Nitrosococcus and Nitrosomonas) appeared less abundant in SK sediments compared to BB sediments. Beggiatoa and Thiothrix 16S rRNA genes were also present, suggesting chemolithoautotrophic NO3- reduction to NO2- or NH4+ as a possible pathway. Our results show the metabolic potential for ammonification, nitrification, DNRA and denitrification activities in North Sea and Baltic Sea sediments.
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Affiliation(s)
- Carolina Reyes
- Microbial Ecophysiology, University of Bremen, Leobener Strasse, D-28359, Bremen, Germany.
- Department of Environmental Geosciences, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria.
| | - Dominik Schneider
- Department of Genomic and Applied Microbiology, University of Göttingen, Grisebachstrasse 8, D-37077, Göttingen, Germany
| | - Marko Lipka
- Geochemistry and Stable Isotope Biogeochemistry Group, Leibniz Institute for Baltic Sea Research (IOW), Seestrasse 15, D-18119, Warnemünde, Germany
| | - Andrea Thürmer
- Department of Genomic and Applied Microbiology, University of Göttingen, Grisebachstrasse 8, D-37077, Göttingen, Germany
| | - Michael E Böttcher
- Geochemistry and Stable Isotope Biogeochemistry Group, Leibniz Institute for Baltic Sea Research (IOW), Seestrasse 15, D-18119, Warnemünde, Germany
| | - Michael W Friedrich
- Microbial Ecophysiology, University of Bremen, Leobener Strasse, D-28359, Bremen, Germany
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22
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Wang J, Song Y. Single cell sequencing: a distinct new field. Clin Transl Med 2017; 6:10. [PMID: 28220395 PMCID: PMC5318355 DOI: 10.1186/s40169-017-0139-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 02/11/2017] [Indexed: 12/12/2022] Open
Abstract
Single cell sequencing (SCS) has become a new approach to study biological heterogeneity. The advancement in technologies for single cell isolation, amplification of genome/transcriptome and next-generation sequencing enables SCS to reveal the inherent properties of a single cell from the large scale of the genome, transcriptome or epigenome at high resolution. Recently, SCS has been widely applied in various clinical and research fields, such as cancer biology and oncology, immunology, microbiology, neurobiology and prenatal diagnosis. In this review, we will discuss the development of SCS methods and focus on the latest clinical and research applications of SCS.
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Affiliation(s)
- Jian Wang
- Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai, 200030, China
| | - Yuanlin Song
- Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai, 200030, China.
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23
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MacGregor BJ. Visualizing Evolutionary Relationships of Multidomain Proteins: An Example from Receiver (REC) Domains of Sensor Histidine Kinases in the Candidatus Maribeggiatoa str. Orange Guaymas Draft Genome. Front Microbiol 2016; 7:1780. [PMID: 27895624 PMCID: PMC5108060 DOI: 10.3389/fmicb.2016.01780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 10/24/2016] [Indexed: 11/20/2022] Open
Abstract
For multidomain proteins, evolutionary changes may occur at the domain as well as the whole-protein level. An example is presented here, with suggestions for how such complicated relationships might be visualized. Earlier analysis of the Candidatus Maribeggiatoa str. Orange Guaymas (BOGUAY; Gammaproteobacteria) single-filament draft genome found evidence of gene exchange with the phylogenetically distant Cyanobacteria, particularly for sensory and signal transduction proteins. Because these are modular proteins, known to undergo frequent duplication, domain swapping, and horizontal gene transfer, a single domain was chosen for analysis. Recognition (REC) domains are short (~125 amino acids) and well conserved, simplifying sequence alignments and phylogenetic calculations. Over 100 of these were identified in the BOGUAY genome and found to have a wide range of inferred phylogenetic relationships. Two sets were chosen here for detailed study. One set of four BOGUAY ORFs has closest relatives among other Beggiatoaceae and Cyanobacteria. A second set of four has REC domains with more mixed affiliations, including other Beggiatoaceae, several sulfate-reducing Deltaproteobacteria and Firmicutes, magnetotactic Nitrospirae, one Shewanella and one Ferrimonas strain (both Gammaproteobacteria), and numerous Vibrio vulnificus and V. navarrensis strains (also Gammaproteobacteria). For an overview of the possible origins of the whole proteins and the surrounding genomic regions, color-coded BLASTP results were produced and displayed against cartoons showing protein domain structure of predicted genes. This is suggested as a visualization method for investigation of possible horizontally transferred regions, giving more detail than scans of DNA composition and codon usage but much faster than carrying out full phylogenetic analyses for multiple proteins. As expected, most of the predicted sensor histidine kinases investigated have two or more segments with distinct BLASTP affiliations. For the first set of BOGUAY ORFs, the flanking regions were also examined, and the results suggest they are embedded in genomic stretches with complex histories. An automated method of creating such visualizations could be generally useful; a wish list for its features is given.
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Affiliation(s)
- Barbara J MacGregor
- Department of Marine Sciences, University of North Carolina-Chapel Hill Chapel Hill, NC, USA
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24
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Rudkjøbing VB, Thomsen TR, Xu Y, Melton-Kreft R, Ahmed A, Eickhardt S, Bjarnsholt T, Poulsen SS, Nielsen PH, Earl JP, Ehrlich GD, Moser C. Comparing culture and molecular methods for the identification of microorganisms involved in necrotizing soft tissue infections. BMC Infect Dis 2016; 16:652. [PMID: 27821087 PMCID: PMC5100109 DOI: 10.1186/s12879-016-1976-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/26/2016] [Indexed: 12/26/2022] Open
Abstract
Background Necrotizing soft tissue infections (NSTIs) are a group of infections affecting all soft tissues. NSTI involves necrosis of the afflicted tissue and is potentially life threatening due to major and rapid destruction of tissue, which often leads to septic shock and organ failure. The gold standard for identification of pathogens is culture; however molecular methods for identification of microorganisms may provide a more rapid result and may be able to identify additional microorganisms that are not detected by culture. Methods In this study, tissue samples (n = 20) obtained after debridement of 10 patients with NSTI were analyzed by standard culture, fluorescence in situ hybridization (FISH) and multiple molecular methods. The molecular methods included analysis of microbial diversity by 1) direct 16S and D2LSU rRNA gene Microseq 2) construction of near full-length 16S rRNA gene clone libraries with subsequent Sanger sequencing for most samples, 3) the Ibis T5000 biosensor and 4) 454-based pyrosequencing. Furthermore, quantitative PCR (qPCR) was used to verify and determine the relative abundance of Streptococcus pyogenes in samples. Results For 70 % of the surgical samples it was possible to identify microorganisms by culture. Some samples did not result in growth (presumably due to administration of antimicrobial therapy prior to sampling). The molecular methods identified microorganisms in 90 % of the samples, and frequently detected additional microorganisms when compared to culture. Although the molecular methods generally gave concordant results, our results indicate that Microseq may misidentify or overlook microorganisms that can be detected by other molecular methods. Half of the patients were found to be infected with S. pyogenes, but several atypical findings were also made including infection by a) Acinetobacter baumannii, b) Streptococcus pneumoniae, and c) fungi, mycoplasma and Fusobacterium necrophorum. Conclusion The study emphasizes that many pathogens can be involved in NSTIs, and that no specific “NSTI causing” combination of species exists. This means that clinicians should be prepared to diagnose and treat any combination of microbial pathogens. Some of the tested molecular methods offer a faster turnaround time combined with a high specificity, which makes supplemental use of such methods attractive for identification of microorganisms, especially for fulminant life-threatening infections such as NSTI.
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Affiliation(s)
- Vibeke Børsholt Rudkjøbing
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Trine Rolighed Thomsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark.,Life Science Division, The Danish Technological Institute, Taastrup, Denmark
| | - Yijuan Xu
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark.,Life Science Division, The Danish Technological Institute, Taastrup, Denmark
| | - Rachael Melton-Kreft
- Center for Genomic Sciences, Allegheny-Singer Research Institute, Pittsburgh, USA
| | - Azad Ahmed
- Center for Genomic Sciences, Allegheny-Singer Research Institute, Pittsburgh, USA
| | - Steffen Eickhardt
- Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Bjarnsholt
- Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Denmark
| | - Steen Seier Poulsen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Per Halkjær Nielsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Joshua P Earl
- Center for Genomic Sciences, Philadelphia, PA, USA.,Departments of Microbiology and Immunology, Center for Advanced Microbial Processing, Institute for Molecular Medicine and Infectious Disease, Philadelphia, PA, USA.,Departments of Microbiology and Immunology, Philadelphia, PA, USA
| | - Garth D Ehrlich
- Center for Genomic Sciences, Philadelphia, PA, USA.,Departments of Microbiology and Immunology, Center for Advanced Microbial Processing, Institute for Molecular Medicine and Infectious Disease, Philadelphia, PA, USA.,Departments of Microbiology and Immunology, Philadelphia, PA, USA.,Otolaryngology-Head and Neck Surgery, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Claus Moser
- Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Denmark.
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25
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Lipsewers YA, Hopmans EC, Meysman FJR, Sinninghe Damsté JS, Villanueva L. Abundance and Diversity of Denitrifying and Anammox Bacteria in Seasonally Hypoxic and Sulfidic Sediments of the Saline Lake Grevelingen. Front Microbiol 2016; 7:1661. [PMID: 27812355 PMCID: PMC5071380 DOI: 10.3389/fmicb.2016.01661] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 10/05/2016] [Indexed: 11/13/2022] Open
Abstract
Denitrifying and anammox bacteria are involved in the nitrogen cycling in marine sediments but the environmental factors that regulate the relative importance of these processes are not well constrained. Here, we evaluated the abundance, diversity, and potential activity of denitrifying, anammox, and sulfide-dependent denitrifying bacteria in the sediments of the seasonally hypoxic saline Lake Grevelingen, known to harbor an active microbial community involved in sulfur oxidation pathways. Depth distributions of 16S rRNA gene, nirS gene of denitrifying and anammox bacteria, aprA gene of sulfur-oxidizing and sulfate-reducing bacteria, and ladderane lipids of anammox bacteria were studied in sediments impacted by seasonally hypoxic bottom waters. Samples were collected down to 5 cm depth (1 cm resolution) at three different locations before (March) and during summer hypoxia (August). The abundance of denitrifying bacteria did not vary despite of differences in oxygen and sulfide availability in the sediments, whereas anammox bacteria were more abundant in the summer hypoxia but in those sediments with lower sulfide concentrations. The potential activity of denitrifying and anammox bacteria as well as of sulfur-oxidizing, including sulfide-dependent denitrifiers and sulfate-reducing bacteria, was potentially inhibited by the competition for nitrate and nitrite with cable and/or Beggiatoa-like bacteria in March and by the accumulation of sulfide in the summer hypoxia. The simultaneous presence and activity of organoheterotrophic denitrifying bacteria, sulfide-dependent denitrifiers, and anammox bacteria suggests a tight network of bacteria coupling carbon-, nitrogen-, and sulfur cycling in Lake Grevelingen sediments.
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Affiliation(s)
- Yvonne A Lipsewers
- Department of Marine Microbiology and Biogeochemistry, Royal Netherlands Institute for Sea Research, Utrecht University Den Burg, Netherlands
| | - Ellen C Hopmans
- Department of Marine Microbiology and Biogeochemistry, Royal Netherlands Institute for Sea Research, Utrecht University Den Burg, Netherlands
| | - Filip J R Meysman
- Department of Estuarine and Delta Systems, Royal Netherlands Institute for Sea Research, Utrecht University Den Burg, Netherlands
| | - Jaap S Sinninghe Damsté
- Department of Marine Microbiology and Biogeochemistry, Royal Netherlands Institute for Sea Research, Utrecht UniversityDen Burg, Netherlands; Faculty of Geosciences, Department of Earth Sciences, Utrecht UniversityUtrecht, Netherlands
| | - Laura Villanueva
- Department of Marine Microbiology and Biogeochemistry, Royal Netherlands Institute for Sea Research, Utrecht University Den Burg, Netherlands
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26
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Valentine DL, Fisher GB, Pizarro O, Kaiser CL, Yoerger D, Breier JA, Tarn J. Autonomous Marine Robotic Technology Reveals an Expansive Benthic Bacterial Community Relevant to Regional Nitrogen Biogeochemistry. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:11057-11065. [PMID: 27706934 DOI: 10.1021/acs.est.6b03584] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Benthic accumulations of filamentous, mat-forming bacteria occur throughout the oceans where bisulfide mingles with oxygen or nitrate, providing key but poorly quantified linkages between elemental cycles of carbon, nitrogen and sulfur. Here we used the autonomous underwater vehicle Sentry to conduct a contiguous, 12.5 km photoimaging survey of sea-floor colonies of filamentous bacteria between 80 and 579 m water depth, spanning the continental shelf to the deep suboxic waters of the Santa Barbara Basin (SBB). The survey provided >31 000 images and revealed contiguous, white-colored bacterial colonization coating > ∼80% of the ocean floor and spanning over 1.6 km, between 487 and 523 m water depth. Based on their localization within the stratified waters of the SBB we hypothesize a dynamic and annular biogeochemical zonation by which the bacteria capitalize on periodic flushing events to accumulate and utilize nitrate. Oceanographic time series data bracket the imaging survey and indicate rapid and contemporaneous nitrate loss, while autonomous capture of microbial communities from the benthic boundary layer concurrent with imaging provides possible identities for the responsible bacteria. Based on these observations we explore the ecological context of such mats and their possible importance in the nitrogen cycle of the SBB.
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Affiliation(s)
| | - G Burch Fisher
- Jackson School of Geosciences, University of Texas , Austin, Texas 78712, United States
| | - Oscar Pizarro
- Australian Center for Field Robotics, University of Sydney , Sydney, Australia
| | - Carl L Kaiser
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution , Woods Hole, Massachusetts 02543, United States
| | - Dana Yoerger
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution , Woods Hole, Massachusetts 02543, United States
| | - John A Breier
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution , Woods Hole, Massachusetts 02543, United States
| | - Jonathan Tarn
- Interdepartmental Graduate Program in Marine Science, University of California , Santa Barbara, California 93106, United States
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27
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Salman-Carvalho V, Fadeev E, Joye SB, Teske A. How Clonal Is Clonal? Genome Plasticity across Multicellular Segments of a "Candidatus Marithrix sp." Filament from Sulfidic, Briny Seafloor Sediments in the Gulf of Mexico. Front Microbiol 2016; 7:1173. [PMID: 27536274 PMCID: PMC4971068 DOI: 10.3389/fmicb.2016.01173] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 07/15/2016] [Indexed: 11/13/2022] Open
Abstract
“Candidatus Marithrix” is a recently described lineage within the group of large sulfur bacteria (Beggiatoaceae, Gammaproteobacteria). This genus of bacteria comprises vacuolated, attached-living filaments that inhabit the sediment surface around vent and seep sites in the marine environment. A single filament is ca. 100 μm in diameter, several millimeters long, and consists of hundreds of clonal cells, which are considered highly polyploid. Based on these characteristics, “Candidatus Marithrix” was used as a model organism for the assessment of genomic plasticity along segments of a single filament using next generation sequencing to possibly identify hotspots of microevolution. Using six consecutive segments of a single filament sampled from a mud volcano in the Gulf of Mexico, we recovered ca. 90% of the “Candidatus Marithrix” genome in each segment. There was a high level of genome conservation along the filament with average nucleotide identities between 99.98 and 100%. Different approaches to assemble all reads into a complete consensus genome could not fill the gaps. Each of the six segment datasets encoded merely a few hundred unique nucleotides and 5 or less unique genes—the residual content was redundant in all datasets. Besides the overall high genomic identity, we identified a similar number of single nucleotide polymorphisms (SNPs) between the clonal segments, which are comparable to numbers reported for other clonal organisms. An increase of SNPs with greater distance of filament segments was not observed. The polyploidy of the cells was apparent when analyzing the heterogeneity of reads within a segment. Here, a strong increase in single nucleotide variants, or “intrasegmental sequence heterogeneity” (ISH) events, was observed. These sites may represent hotspots for genome plasticity, and possibly microevolution, since two thirds of these variants were not co-localized across the genome copies of the multicellular filament.
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Affiliation(s)
- Verena Salman-Carvalho
- HGF MPG Joint Research Group for Deep-Sea Ecology and Technology, Max Planck Institute for Marine Microbiology Bremen, Germany
| | - Eduard Fadeev
- HGF MPG Joint Research Group for Deep-Sea Ecology and Technology, Max Planck Institute for Marine Microbiology Bremen, Germany
| | - Samantha B Joye
- Department of Marine Sciences, University of Georgia Athens, GA, USA
| | - Andreas Teske
- Department of Marine Sciences, University of North Carolina at Chapel Hill Chapel Hill, NC, USA
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28
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Jessen GL, Lichtschlag A, Struck U, Boetius A. Distribution and Composition of Thiotrophic Mats in the Hypoxic Zone of the Black Sea (150-170 m Water Depth, Crimea Margin). Front Microbiol 2016; 7:1011. [PMID: 27446049 PMCID: PMC4925705 DOI: 10.3389/fmicb.2016.01011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 06/14/2016] [Indexed: 01/28/2023] Open
Abstract
At the Black Sea chemocline, oxygen- and sulfide-rich waters meet and form a niche for thiotrophic pelagic bacteria. Here we investigated an area of the Northwestern Black Sea off Crimea close to the shelf break, where the chemocline reaches the seafloor at around 150-170 m water depth, to assess whether thiotrophic bacteria are favored in this zone. Seafloor video transects were carried out with the submersible JAGO covering 20 km(2) on the region between 110 and 200 m depth. Around the chemocline we observed irregular seafloor depressions, covered with whitish mats of large filamentous bacteria. These comprised 25-55% of the seafloor, forming a belt of 3 km width around the chemocline. Cores from the mats obtained with JAGO showed higher accumulations of organic matter under the mats compared to mat-free sediments. The mat-forming bacteria were related to Beggiatoa-like large filamentous sulfur bacteria based on 16S rRNA sequences from the mat, and visual characteristics. The microbial community under the mats was significantly different from the surrounding sediments and enriched with taxa affiliated with polymer degrading, fermenting and sulfate reducing microorganisms. Under the mats, higher organic matter accumulation, as well as higher remineralization and radiotracer-based sulfate reduction rates were measured compared to outside the mat. Mat-covered and mat-free sediments showed similar degradability of the bulk organic matter pool, suggesting that the higher sulfide fluxes and subsequent development of the thiotrophic mats in the patches are consequences of the accumulation of organic matter rather than its qualitative composition. Our observations suggest that the key factors for the distribution of thiotrophic mat-forming communities near to the Crimean shelf break are hypoxic conditions that (i) repress grazers, (ii) enhance the accumulation and degradation of labile organic matter by sulfate-reducers, and (iii) favor thiotrophic filamentous bacteria which are adapted to exploit steep gradients in oxygen and sulfide availability; in addition to a specific seafloor topography which may relate to internal waves at the shelf break.
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Affiliation(s)
- Gerdhard L Jessen
- HGF-MPG Group for Deep Sea Ecology and Technology, Max Planck Institute for Marine Microbiology Bremen, Germany
| | - Anna Lichtschlag
- HGF-MPG Group for Deep Sea Ecology and Technology, Max Planck Institute for Marine Microbiology Bremen, Germany
| | - Ulrich Struck
- Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung Berlin, Germany
| | - Antje Boetius
- HGF-MPG Group for Deep Sea Ecology and Technology, Max Planck Institute for Marine MicrobiologyBremen, Germany; Alfred Wegener Institute, Helmholtz Center for Polar and Marine ResearchBremerhaven, Germany
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29
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Winkel M, Salman-Carvalho V, Woyke T, Richter M, Schulz-Vogt HN, Flood BE, Bailey JV, Mußmann M. Single-cell Sequencing of Thiomargarita Reveals Genomic Flexibility for Adaptation to Dynamic Redox Conditions. Front Microbiol 2016; 7:964. [PMID: 27446006 PMCID: PMC4914600 DOI: 10.3389/fmicb.2016.00964] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 06/03/2016] [Indexed: 11/25/2022] Open
Abstract
Large, colorless sulfur-oxidizing bacteria (LSB) of the family Beggiatoaceae form thick mats at sulfidic sediment surfaces, where they efficiently detoxify sulfide before it enters the water column. The genus Thiomargarita harbors the largest known free-living bacteria with cell sizes of up to 750 μm in diameter. In addition to their ability to oxidize reduced sulfur compounds, some Thiomargarita spp. are known to store large amounts of nitrate, phosphate and elemental sulfur internally. To date little is known about their energy yielding metabolic pathways, and how these pathways compare to other Beggiatoaceae. Here, we present a draft single-cell genome of a chain-forming “Candidatus Thiomargarita nelsonii Thio36”, and conduct a comparative analysis to five draft and one full genome of other members of the Beggiatoaceae. “Ca. T. nelsonii Thio36” is able to respire nitrate to both ammonium and dinitrogen, which allows them to flexibly respond to environmental changes. Genes for sulfur oxidation and inorganic carbon fixation confirmed that “Ca. T. nelsonii Thio36” can function as a chemolithoautotroph. Carbon can be fixed via the Calvin–Benson–Bassham cycle, which is common among the Beggiatoaceae. In addition we found key genes of the reductive tricarboxylic acid cycle that point toward an alternative CO2 fixation pathway. Surprisingly, “Ca. T. nelsonii Thio36” also encodes key genes of the C2-cycle that convert 2-phosphoglycolate to 3-phosphoglycerate during photorespiration in higher plants and cyanobacteria. Moreover, we identified a novel trait of a flavin-based energy bifurcation pathway coupled to a Na+-translocating membrane complex (Rnf). The coupling of these pathways may be key to surviving long periods of anoxia. As other Beggiatoaceae “Ca. T. nelsonii Thio36” encodes many genes similar to those of (filamentous) cyanobacteria. In summary, the genome of “Ca. T. nelsonii Thio36” provides additional insight into the ecology of giant sulfur-oxidizing bacteria, and reveals unique genomic features for the Thiomargarita lineage within the Beggiatoaceae.
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Affiliation(s)
- Matthias Winkel
- Molecular Ecology Group, Department of Molecular Ecology, Max Planck Institute for Marine MicrobiologyBremen, Germany; Section Geomicrobiology, GFZ German Research Centre for Geoscience, Helmholtz Centre PotsdamPotsdam, Germany
| | - Verena Salman-Carvalho
- HGF MPG Joint Research Group for Deep-sea Ecology and Technology, Max Planck Institute for Marine Microbiology Bremen, Germany
| | - Tanja Woyke
- Department of Energy Joint Genome Institute, Walnut Creek CA, USA
| | - Michael Richter
- Microbial Genomics and Bioinformatics Group, Department of Molecular Ecology, Max Planck Institute for Marine Microbiology Bremen, Germany
| | | | - Beverly E Flood
- Department of Earth Sciences, University of Minnesota, Minneapolis MN, USA
| | - Jake V Bailey
- Department of Earth Sciences, University of Minnesota, Minneapolis MN, USA
| | - Marc Mußmann
- Molecular Ecology Group, Department of Molecular Ecology, Max Planck Institute for Marine Microbiology Bremen, Germany
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30
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Trojan D, Schreiber L, Bjerg JT, Bøggild A, Yang T, Kjeldsen KU, Schramm A. A taxonomic framework for cable bacteria and proposal of the candidate genera Electrothrix and Electronema. Syst Appl Microbiol 2016; 39:297-306. [PMID: 27324572 PMCID: PMC4958695 DOI: 10.1016/j.syapm.2016.05.006] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 05/06/2016] [Accepted: 05/09/2016] [Indexed: 11/29/2022]
Abstract
Cable bacteria are long, multicellular filaments that can conduct electric currents over centimeter-scale distances. All cable bacteria identified to date belong to the deltaproteobacterial family Desulfobulbaceae and have not been isolated in pure culture yet. Their taxonomic delineation and exact phylogeny is uncertain, as most studies so far have reported only short partial 16S rRNA sequences or have relied on identification by a combination of filament morphology and 16S rRNA-targeted fluorescence in situ hybridization with a Desulfobulbaceae-specific probe. In this study, nearly full-length 16S rRNA gene sequences of 16 individual cable bacteria filaments from freshwater, salt marsh, and marine sites of four geographic locations are presented. These sequences formed a distinct, monophyletic sister clade to the genus Desulfobulbus and could be divided into six coherent, species-level clusters, arranged as two genus-level groups. The same grouping was retrieved by phylogenetic analysis of full or partial dsrAB genes encoding the dissimilatory sulfite reductase. Based on these results, it is proposed to accommodate cable bacteria within two novel candidate genera: the mostly marine “Candidatus Electrothrix”, with four candidate species, and the mostly freshwater “Candidatus Electronema”, with two candidate species. This taxonomic framework can be used to assign environmental sequences confidently to the cable bacteria clade, even without morphological information. Database searches revealed 185 16S rRNA gene sequences that affiliated within the clade formed by the proposed cable bacteria genera, of which 120 sequences could be assigned to one of the six candidate species, while the remaining 65 sequences indicated the existence of up to five additional species.
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Affiliation(s)
- Daniela Trojan
- Section for Microbiology & Center for Geomicrobiology, Department of Bioscience, Aarhus University, Ny Munkegade 114, 8000 Aarhus C, Denmark.
| | - Lars Schreiber
- Section for Microbiology & Center for Geomicrobiology, Department of Bioscience, Aarhus University, Ny Munkegade 114, 8000 Aarhus C, Denmark
| | - Jesper T Bjerg
- Section for Microbiology & Center for Geomicrobiology, Department of Bioscience, Aarhus University, Ny Munkegade 114, 8000 Aarhus C, Denmark
| | - Andreas Bøggild
- Section for Microbiology & Center for Geomicrobiology, Department of Bioscience, Aarhus University, Ny Munkegade 114, 8000 Aarhus C, Denmark
| | - Tingting Yang
- Section for Microbiology & Center for Geomicrobiology, Department of Bioscience, Aarhus University, Ny Munkegade 114, 8000 Aarhus C, Denmark
| | - Kasper U Kjeldsen
- Section for Microbiology & Center for Geomicrobiology, Department of Bioscience, Aarhus University, Ny Munkegade 114, 8000 Aarhus C, Denmark
| | - Andreas Schramm
- Section for Microbiology & Center for Geomicrobiology, Department of Bioscience, Aarhus University, Ny Munkegade 114, 8000 Aarhus C, Denmark.
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Structural insight into photoactivation of an adenylate cyclase from a photosynthetic cyanobacterium. Proc Natl Acad Sci U S A 2016; 113:6659-64. [PMID: 27247413 DOI: 10.1073/pnas.1517520113] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cyclic-AMP is one of the most important second messengers, regulating many crucial cellular events in both prokaryotes and eukaryotes, and precise spatial and temporal control of cAMP levels by light shows great promise as a simple means of manipulating and studying numerous cell pathways and processes. The photoactivated adenylate cyclase (PAC) from the photosynthetic cyanobacterium Oscillatoria acuminata (OaPAC) is a small homodimer eminently suitable for this task, requiring only a simple flavin chromophore within a blue light using flavin (BLUF) domain. These domains, one of the most studied types of biological photoreceptor, respond to blue light and either regulate the activity of an attached enzyme domain or change its affinity for a repressor protein. BLUF domains were discovered through studies of photo-induced movements of Euglena gracilis, a unicellular flagellate, and gene expression in the purple bacterium Rhodobacter sphaeroides, but the precise details of light activation remain unknown. Here, we describe crystal structures and the light regulation mechanism of the previously undescribed OaPAC, showing a central coiled coil transmits changes from the light-sensing domains to the active sites with minimal structural rearrangement. Site-directed mutants show residues essential for signal transduction over 45 Å across the protein. The use of the protein in living human cells is demonstrated with cAMP-dependent luciferase, showing a rapid and stable response to light over many hours and activation cycles. The structures determined in this study will assist future efforts to create artificial light-regulated control modules as part of a general optogenetic toolkit.
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Flood BE, Fliss P, Jones DS, Dick GJ, Jain S, Kaster AK, Winkel M, Mußmann M, Bailey J. Single-Cell (Meta-)Genomics of a Dimorphic Candidatus Thiomargarita nelsonii Reveals Genomic Plasticity. Front Microbiol 2016; 7:603. [PMID: 27199933 PMCID: PMC4853749 DOI: 10.3389/fmicb.2016.00603] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 04/11/2016] [Indexed: 11/23/2022] Open
Abstract
The genus Thiomargarita includes the world's largest bacteria. But as uncultured organisms, their physiology, metabolism, and basis for their gigantism are not well understood. Thus, a genomics approach, applied to a single Candidatus Thiomargarita nelsonii cell was employed to explore the genetic potential of one of these enigmatic giant bacteria. The Thiomargarita cell was obtained from an assemblage of budding Ca. T. nelsonii attached to a provannid gastropod shell from Hydrate Ridge, a methane seep offshore of Oregon, USA. Here we present a manually curated genome of Bud S10 resulting from a hybrid assembly of long Pacific Biosciences and short Illumina sequencing reads. With respect to inorganic carbon fixation and sulfur oxidation pathways, the Ca. T. nelsonii Hydrate Ridge Bud S10 genome was similar to marine sister taxa within the family Beggiatoaceae. However, the Bud S10 genome contains genes suggestive of the genetic potential for lithotrophic growth on arsenite and perhaps hydrogen. The genome also revealed that Bud S10 likely respires nitrate via two pathways: a complete denitrification pathway and a dissimilatory nitrate reduction to ammonia pathway. Both pathways have been predicted, but not previously fully elucidated, in the genomes of other large, vacuolated, sulfur-oxidizing bacteria. Surprisingly, the genome also had a high number of unusual features for a bacterium to include the largest number of metacaspases and introns ever reported in a bacterium. Also present, are a large number of other mobile genetic elements, such as insertion sequence (IS) transposable elements and miniature inverted-repeat transposable elements (MITEs). In some cases, mobile genetic elements disrupted key genes in metabolic pathways. For example, a MITE interrupts hupL, which encodes the large subunit of the hydrogenase in hydrogen oxidation. Moreover, we detected a group I intron in one of the most critical genes in the sulfur oxidation pathway, dsrA. The dsrA group I intron also carried a MITE sequence that, like the hupL MITE family, occurs broadly across the genome. The presence of a high degree of mobile elements in genes central to Thiomargarita's core metabolism has not been previously reported in free-living bacteria and suggests a highly mutable genome.
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Affiliation(s)
- Beverly E Flood
- Department of Earth Sciences, University of Minnesota Minneapolis, MN, USA
| | - Palmer Fliss
- Department of Earth Sciences, University of Minnesota Minneapolis, MN, USA
| | - Daniel S Jones
- Department of Earth Sciences, University of MinnesotaMinneapolis, MN, USA; Biotechnology Institute, University of MinnesotaSt. Paul, MN, USA
| | - Gregory J Dick
- Department of Earth and Environmental Sciences, University of Michigan Ann Arbor, MI, USA
| | - Sunit Jain
- Department of Earth and Environmental Sciences, University of Michigan Ann Arbor, MI, USA
| | - Anne-Kristin Kaster
- German Collection of Microorganisms and Cell Cultures, Leibniz Institute DSMZ Braunschweig, Germany
| | - Matthias Winkel
- Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences Potsdam, Germany
| | - Marc Mußmann
- Max Planck Institute for Marine Microbiology Bremen, Germany
| | - Jake Bailey
- Department of Earth Sciences, University of Minnesota Minneapolis, MN, USA
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Oxidation of Molecular Hydrogen by a Chemolithoautotrophic Beggiatoa Strain. Appl Environ Microbiol 2016; 82:2527-36. [PMID: 26896131 PMCID: PMC4959497 DOI: 10.1128/aem.03818-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 02/10/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED A chemolithoautotrophic strain of the family Beggiatoaceae, Beggiatoa sp. strain 35Flor, was found to oxidize molecular hydrogen when grown in a medium with diffusional gradients of oxygen, sulfide, and hydrogen. Microsensor profiles and rate measurements suggested that the strain oxidized hydrogen aerobically when oxygen was available, while hydrogen consumption under anoxic conditions was presumably driven by sulfur respiration.Beggiatoa sp. 35Flor reached significantly higher biomass in hydrogen-supplemented oxygen-sulfide gradient media, but hydrogen did not support growth of the strain in the absence of reduced sulfur compounds. Nevertheless, hydrogen oxidation can provide Beggiatoa sp. 35Flor with energy for maintenance and assimilatory purposes and may support the disposal of internally stored sulfur to prevent physical damage resulting from excessive sulfur accumulation. Our knowledge about the exposure of natural populations of Beggiatoa ceae to hydrogen is very limited, but significant amounts of hydrogen could be provided by nitrogen fixation, fermentation, and geochemical processes in several of their typical habitats such as photosynthetic microbial mats and submarine sites of hydrothermal fluid flow. IMPORTANCE Reduced sulfur compounds are certainly the main electron donors for chemolithoautotrophic Beggiatoa ceae, but the traditional focus on this topic has left other possible inorganic electron donors largely unexplored. In this paper, we provide evidence that hydrogen oxidation has the potential to strengthen the ecophysiological plasticity of Beggiatoa ceaein several ways. Moreover, we show that hydrogen oxidation by members of this family can significantly influence biogeochemical gradients and therefore should be considered in environmental studies.
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Houghton JL, Foustoukos DI, Flynn TM, Vetriani C, Bradley AS, Fike DA. Thiosulfate oxidation by Thiomicrospira thermophila: metabolic flexibility in response to ambient geochemistry. Environ Microbiol 2016; 18:3057-72. [PMID: 26914243 DOI: 10.1111/1462-2920.13232] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 01/17/2016] [Indexed: 11/29/2022]
Abstract
Previous studies of the stoichiometry of thiosulfate oxidation by colorless sulfur bacteria have failed to demonstrate mass balance of sulfur, indicating that unidentified oxidized products must be present. Here the reaction stoichiometry and kinetics under variable pH conditions during the growth of Thiomicrospira thermophila strain EPR85, isolated from diffuse hydrothermal fluids at the East Pacific Rise, is presented. At pH 8.0, thiosulfate was stoichiometrically converted to sulfate. At lower pH, the products of thiosulfate oxidation were extracellular elemental sulfur and sulfate. We were able to replicate previous experiments and identify the missing sulfur as tetrathionate, consistent with previous reports of the activity of thiosulfate dehydrogenase. Tetrathionate was formed under slightly acidic conditions. Genomic DNA from T. thermophila strain EPR85 contains genes homologous to those in the Sox pathway (soxAXYZBCDL), as well as rhodanese and thiosulfate dehydrogenase. No other sulfur oxidizing bacteria containing sox(CD)2 genes have been reported to produce extracellular elemental sulfur. If the apparent modified Sox pathway we observed in T. thermophila is present in marine Thiobacillus and Thiomicrospira species, production of extracellular elemental sulfur may be biogeochemically important in marine sulfur cycling.
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Affiliation(s)
- J L Houghton
- Department of Earth and Planetary Sciences, Washington University, St. Louis, MO, 63130, USA.
| | - D I Foustoukos
- Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC, 20015, USA
| | - T M Flynn
- Biosciences Division, Argonne National Laboratory, Lemont, IL, 60439, USA.,Computation Institution, The University of Chicago, Chicago, IL, 60637, USA
| | - C Vetriani
- Department of Biochemistry and Microbiology and Institute of Earth, Ocean and Atmospheric Sciences, Rutgers University, New Brunswick, NJ, 08901, USA
| | - Alexander S Bradley
- Department of Earth and Planetary Sciences, Washington University, St. Louis, MO, 63130, USA
| | - D A Fike
- Department of Earth and Planetary Sciences, Washington University, St. Louis, MO, 63130, USA
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Kamp A, Høgslund S, Risgaard-Petersen N, Stief P. Nitrate Storage and Dissimilatory Nitrate Reduction by Eukaryotic Microbes. Front Microbiol 2015; 6:1492. [PMID: 26734001 PMCID: PMC4686598 DOI: 10.3389/fmicb.2015.01492] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 12/10/2015] [Indexed: 11/13/2022] Open
Abstract
The microbial nitrogen cycle is one of the most complex and environmentally important element cycles on Earth and has long been thought to be mediated exclusively by prokaryotic microbes. Rather recently, it was discovered that certain eukaryotic microbes are able to store nitrate intracellularly and use it for dissimilatory nitrate reduction in the absence of oxygen. The paradigm shift that this entailed is ecologically significant because the eukaryotes in question comprise global players like diatoms, foraminifers, and fungi. This review article provides an unprecedented overview of nitrate storage and dissimilatory nitrate reduction by diverse marine eukaryotes placed into an eco-physiological context. The advantage of intracellular nitrate storage for anaerobic energy conservation in oxygen-depleted habitats is explained and the life style enabled by this metabolic trait is described. A first compilation of intracellular nitrate inventories in various marine sediments is presented, indicating that intracellular nitrate pools vastly exceed porewater nitrate pools. The relative contribution by foraminifers to total sedimentary denitrification is estimated for different marine settings, suggesting that eukaryotes may rival prokaryotes in terms of dissimilatory nitrate reduction. Finally, this review article sketches some evolutionary perspectives of eukaryotic nitrate metabolism and identifies open questions that need to be addressed in future investigations.
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Affiliation(s)
- Anja Kamp
- AIAS, Aarhus Institute of Advanced Studies Aarhus University Aarhus, Denmark
| | - Signe Høgslund
- Department of Bioscience, Aarhus University Aarhus, Denmark
| | | | - Peter Stief
- Department of Biology, Nordic Center for Earth Evolution, University of Southern Denmark Odense, Denmark
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MacGregor BJ. Abundant Intergenic TAACTGA Direct Repeats and Putative Alternate RNA Polymerase β' Subunits in Marine Beggiatoaceae Genomes: Possible Regulatory Roles and Origins. Front Microbiol 2015; 6:1397. [PMID: 26733950 PMCID: PMC4679880 DOI: 10.3389/fmicb.2015.01397] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 11/23/2015] [Indexed: 12/15/2022] Open
Abstract
The genome sequences of several giant marine sulfur-oxidizing bacteria present evidence of a possible post-transcriptional regulatory network that may have been transmitted to or from two distantly related bacteria lineages. The draft genome of a Cand. “Maribeggiatoa” filament from the Guaymas Basin (Gulf of California, Mexico) seafloor contains 169 sets of TAACTGA direct repeats and one indirect repeat, with two to six copies per set. Related heptamers are rarely or never found as direct repeats. TAACTGA direct repeats are also found in some other Beggiatoaceae, Thiocystis violascens, a range of Cyanobacteria, and five Bacteroidetes. This phylogenetic distribution suggests they may have been transmitted horizontally, but no mechanism is evident. There is no correlation between total TAACTGA occurrences and repeats per genome. In most species the repeat units are relatively short, but longer arrays of up to 43 copies are found in several Bacteroidetes and Cyanobacteria. The majority of TAACTGA repeats in the Cand. “Maribeggiatoa” Orange Guaymas (BOGUAY) genome are within several nucleotides upstream of a putative start codon, suggesting they may be binding sites for a post-transcriptional regulator. Candidates include members of the ribosomal protein S1, Csp (cold shock protein), and Csr (carbon storage regulator) families. No pattern was evident in the predicted functions of the open reading frames (ORFs) downstream of repeats, but some encode presumably essential products such as ribosomal proteins. Among these is an ORF encoding a possible alternate or modified RNA polymerase beta prime subunit, predicted to have the expected subunit interaction domains but lacking most catalytic residues. A similar ORF was found in the Thioploca ingrica draft genome, but in no others. In both species they are immediately upstream of putative sensor kinase genes with nearly identical domain structures. In the marine Beggiatoaceae, a role for the TAACTGA repeats in translational regulation is suggested. More speculatively, the putative alternate RNA polymerase subunit could be a negative transcriptional regulator.
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Affiliation(s)
- Barbara J MacGregor
- Department of Marine Sciences, University of North Carolina-Chapel Hill Chapel Hill, NC, USA
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Salman V, Yang T, Berben T, Klein F, Angert E, Teske A. Calcite-accumulating large sulfur bacteria of the genus Achromatium in Sippewissett Salt Marsh. THE ISME JOURNAL 2015; 9:2503-14. [PMID: 25909974 PMCID: PMC4611513 DOI: 10.1038/ismej.2015.62] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Revised: 03/17/2015] [Accepted: 03/20/2015] [Indexed: 11/08/2022]
Abstract
Large sulfur bacteria of the genus Achromatium are exceptional among Bacteria and Archaea as they can accumulate high amounts of internal calcite. Although known for more than 100 years, they remain uncultured, and only freshwater populations have been studied so far. Here we investigate a marine population of calcite-accumulating bacteria that is primarily found at the sediment surface of tide pools in a salt marsh, where high sulfide concentrations meet oversaturated oxygen concentrations during the day. Dynamic sulfur cycling by phototrophic sulfide-oxidizing and heterotrophic sulfate-reducing bacteria co-occurring in these sediments creates a highly sulfidic environment that we propose induces behavioral differences in the Achromatium population compared with reported migration patterns in a low-sulfide environment. Fluctuating intracellular calcium/sulfur ratios at different depths and times of day indicate a biochemical reaction of the salt marsh Achromatium to diurnal changes in sedimentary redox conditions. We correlate this calcite dynamic with new evidence regarding its formation/mobilization and suggest general implications as well as a possible biological function of calcite accumulation in large bacteria in the sediment environment that is governed by gradients. Finally, we propose a new taxonomic classification of the salt marsh Achromatium based on their adaptation to a significantly different habitat than their freshwater relatives, as indicated by their differential behavior as well as phylogenetic distance on 16S ribosomal RNA gene level. In future studies, whole-genome characterization and additional ecophysiological factors could further support the distinctive position of salt marsh Achromatium.
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Affiliation(s)
- Verena Salman
- Department of Microbiology, Cornell University, Ithaca, NY, USA
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Tingting Yang
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Tom Berben
- Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Frieder Klein
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Esther Angert
- Department of Microbiology, Cornell University, Ithaca, NY, USA
| | - Andreas Teske
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Mansor M, Hamilton TL, Fantle MS, Macalady JL. Metabolic diversity and ecological niches of Achromatium populations revealed with single-cell genomic sequencing. Front Microbiol 2015; 6:822. [PMID: 26322031 PMCID: PMC4530308 DOI: 10.3389/fmicb.2015.00822] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 07/27/2015] [Indexed: 11/13/2022] Open
Abstract
Large, sulfur-cycling, calcite-precipitating bacteria in the genus Achromatium represent a significant proportion of bacterial communities near sediment-water interfaces at sites throughout the world. Our understanding of their potentially crucial roles in calcium, carbon, sulfur, nitrogen, and iron cycling is limited because they have not been cultured or sequenced using environmental genomics approaches to date. We utilized single-cell genomic sequencing to obtain one incomplete and two nearly complete draft genomes for Achromatium collected at Warm Mineral Springs (WMS), FL. Based on 16S rRNA gene sequences, the three cells represent distinct and relatively distant Achromatium populations (91-92% identity). The draft genomes encode key genes involved in sulfur and hydrogen oxidation; oxygen, nitrogen and polysulfide respiration; carbon and nitrogen fixation; organic carbon assimilation and storage; chemotaxis; twitching motility; antibiotic resistance; and membrane transport. Known genes for iron and manganese energy metabolism were not detected. The presence of pyrophosphatase and vacuolar (V)-type ATPases, which are generally rare in bacterial genomes, suggests a role for these enzymes in calcium transport, proton pumping, and/or energy generation in the membranes of calcite-containing inclusions.
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Affiliation(s)
- Muammar Mansor
- Geosciences Department, Pennsylvania State University University Park, PA, USA
| | - Trinity L Hamilton
- Department of Biological Sciences, University of Cincinnati Cincinnati, OH, USA
| | - Matthew S Fantle
- Geosciences Department, Pennsylvania State University University Park, PA, USA
| | - Jennifer L Macalady
- Geosciences Department, Pennsylvania State University University Park, PA, USA
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Gasc C, Ribière C, Parisot N, Beugnot R, Defois C, Petit-Biderre C, Boucher D, Peyretaillade E, Peyret P. Capturing prokaryotic dark matter genomes. Res Microbiol 2015; 166:814-30. [PMID: 26100932 DOI: 10.1016/j.resmic.2015.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 06/02/2015] [Accepted: 06/03/2015] [Indexed: 11/18/2022]
Abstract
Prokaryotes are the most diverse and abundant cellular life forms on Earth. Most of them, identified by indirect molecular approaches, belong to microbial dark matter. The advent of metagenomic and single-cell genomic approaches has highlighted the metabolic capabilities of numerous members of this dark matter through genome reconstruction. Thus, linking functions back to the species has revolutionized our understanding of how ecosystem function is sustained by the microbial world. This review will present discoveries acquired through the illumination of prokaryotic dark matter genomes by these innovative approaches.
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Affiliation(s)
- Cyrielle Gasc
- Clermont Université, Université d'Auvergne, EA 4678 CIDAM, BP 10448, F-63001 Clermont-Ferrand, France.
| | - Céline Ribière
- Clermont Université, Université d'Auvergne, EA 4678 CIDAM, BP 10448, F-63001 Clermont-Ferrand, France.
| | - Nicolas Parisot
- Biologie Fonctionnelle Insectes et Interactions, UMR203 BF2I, INRA, INSA-Lyon, Université de Lyon, Villeurbanne, France.
| | - Réjane Beugnot
- Clermont Université, Université d'Auvergne, EA 4678 CIDAM, BP 10448, F-63001 Clermont-Ferrand, France.
| | - Clémence Defois
- Clermont Université, Université d'Auvergne, EA 4678 CIDAM, BP 10448, F-63001 Clermont-Ferrand, France.
| | - Corinne Petit-Biderre
- Université Blaise Pascal, Laboratoire Microorganismes, Génome et Environnement, Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 6023, F-63171 Aubière, France.
| | - Delphine Boucher
- Clermont Université, Université d'Auvergne, EA 4678 CIDAM, BP 10448, F-63001 Clermont-Ferrand, France.
| | - Eric Peyretaillade
- Clermont Université, Université d'Auvergne, EA 4678 CIDAM, BP 10448, F-63001 Clermont-Ferrand, France.
| | - Pierre Peyret
- Clermont Université, Université d'Auvergne, EA 4678 CIDAM, BP 10448, F-63001 Clermont-Ferrand, France.
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Kojima H, Ogura Y, Yamamoto N, Togashi T, Mori H, Watanabe T, Nemoto F, Kurokawa K, Hayashi T, Fukui M. Ecophysiology of Thioploca ingrica as revealed by the complete genome sequence supplemented with proteomic evidence. THE ISME JOURNAL 2015; 9:1166-76. [PMID: 25343513 PMCID: PMC4409161 DOI: 10.1038/ismej.2014.209] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 09/17/2014] [Accepted: 09/22/2014] [Indexed: 01/15/2023]
Abstract
Large sulfur-oxidizing bacteria, which accumulate a high concentration of nitrate, are important constituents of aquatic sediment ecosystems. No representative of this group has been isolated in pure culture, and only fragmented draft genome sequences are available for these microorganisms. In this study, we successfully reconstituted the genome of Thioploca ingrica from metagenomic sequences, thereby generating the first complete genome sequence from this group. The Thioploca samples for the metagenomic analysis were obtained from a freshwater lake in Japan. A PCR-free paired-end library was constructed from the DNA extracted from the samples and was sequenced on the Illumina MiSeq platform. By closing gaps within and between the scaffolds, we obtained a circular chromosome and a plasmid-like element. The reconstituted chromosome was 4.8 Mbp in length with a 41.2% GC content. A sulfur oxidation pathway identical to that suggested for the closest relatives of Thioploca was deduced from the reconstituted genome. A full set of genes required for respiratory nitrate reduction to dinitrogen gas was also identified. We further performed a proteomic analysis of the Thioploca sample and detected many enzymes/proteins involved in sulfur oxidation, nitrate respiration and inorganic carbon fixation as major components of the protein extracts from the sample, suggesting that these metabolic activities are strongly associated with the physiology of T. ingrica in lake sediment.
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Affiliation(s)
- Hisaya Kojima
- The Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
| | - Yoshitoshi Ogura
- Division of Microbial Genomics, Department of Genomics and Bioenvironmental Science, Frontier Science Research Center, University of Miyazaki, Miyazaki, Japan
- Division of Microbiology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Nozomi Yamamoto
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
| | - Tomoaki Togashi
- Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Tokyo, Japan
| | - Hiroshi Mori
- Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Tokyo, Japan
| | - Tomohiro Watanabe
- The Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
| | - Fumiko Nemoto
- The Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
| | - Ken Kurokawa
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
- Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Tokyo, Japan
| | - Tetsuya Hayashi
- Division of Microbial Genomics, Department of Genomics and Bioenvironmental Science, Frontier Science Research Center, University of Miyazaki, Miyazaki, Japan
- Division of Microbiology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Manabu Fukui
- The Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
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Metatranscriptomic analysis of diminutive Thiomargarita-like bacteria ("Candidatus Thiopilula" spp.) from abyssal cold seeps of the Barbados Accretionary Prism. Appl Environ Microbiol 2015; 81:3142-56. [PMID: 25724961 DOI: 10.1128/aem.00039-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 02/23/2015] [Indexed: 11/20/2022] Open
Abstract
Large sulfur-oxidizing bacteria in the family Beggiatoaceae are important players in the global sulfur cycle. This group contains members of the well-known genera Beggiatoa, Thioploca, and Thiomargarita but also recently identified and relatively unknown candidate taxa, including "Candidatus Thiopilula" spp. and "Ca. Thiophysa" spp. We discovered a population of "Ca. Thiopilula" spp. colonizing cold seeps near Barbados at a ∼4.7-km water depth. The Barbados population consists of spherical cells that are morphologically similar to Thiomargarita spp., with elemental sulfur inclusions and a central vacuole, but have much smaller cell diameters (5 to 40 μm). Metatranscriptomic analysis revealed that when exposed to anoxic sulfidic conditions, Barbados "Ca. Thiopilula" organisms expressed genes for the oxidation of elemental sulfur and the reduction of nitrogenous compounds, consistent with their vacuolated morphology and intracellular sulfur storage capability. Metatranscriptomic analysis further revealed that anaerobic methane-oxidizing and sulfate-reducing organisms were active in the sediment, which likely provided reduced sulfur substrates for "Ca. Thiopilula" and other sulfur-oxidizing microorganisms in the community. The novel observations of "Ca. Thiopilula" and associated organisms reported here expand our knowledge of the globally distributed and ecologically successful Beggiatoaceae group and thus offer insight into the composition and ecology of deep cold seep microbial communities.
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Two new Beggiatoa species inhabiting marine mangrove sediments in the Caribbean. PLoS One 2015; 10:e0117832. [PMID: 25689402 PMCID: PMC4331518 DOI: 10.1371/journal.pone.0117832] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 12/31/2014] [Indexed: 11/19/2022] Open
Abstract
Beggiatoaceae, giant sulphur-oxidizing bacteria, are well known to occur in cold and temperate waters, as well as hydrothermal vents, where they form dense mats on the floor. However, they have never been described in tropical marine mangroves. Here, we describe two new species of benthic Beggiatoaceae colonizing a marine mangrove adjacent to mangrove roots. We combined phylogenetic and lipid analysis with electron microscopy in order to describe these organisms. Furthermore, oxygen and sulphide measurements in and ex situ were performed in a mesocosm to characterize their environment. Based on this, two new species, Candidatus Maribeggiatoa sp. and Candidatus Isobeggiatoa sp. inhabiting tropical marine mangroves in Guadeloupe were identified. The species identified as Candidatus Maribeggiatoa group suggests that this genus could harbour a third cluster with organisms ranging from 60 to 120 μm in diameter. This is also the first description of an Isobeggiatoa species outside of Arctic and temperate waters. The multiphasic approach also gives information about the environment and indications for the metabolism of these bacteria. Our study shows the widespread occurrence of members of Beggiatoaceae family and provides new insight in their potential role in shallow-water marine sulphide-rich environments such as mangroves.
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Rapid redox signal transmission by "Cable Bacteria" beneath a photosynthetic biofilm. Appl Environ Microbiol 2014; 81:948-56. [PMID: 25416774 DOI: 10.1128/aem.02682-14] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recently, long filamentous bacteria, belonging to the family Desulfobulbaceae, were shown to induce electrical currents over long distances in the surface layer of marine sediments. These "cable bacteria" are capable of harvesting electrons from free sulfide in deeper sediment horizons and transferring these electrons along their longitudinal axes to oxygen present near the sediment-water interface. In the present work, we investigated the relationship between cable bacteria and a photosynthetic algal biofilm. In a first experiment, we investigated sediment that hosted both cable bacteria and a photosynthetic biofilm and tested the effect of an imposed diel light-dark cycle by continuously monitoring sulfide at depth. Changes in photosynthesis at the sediment surface had an immediate and repeatable effect on sulfide concentrations at depth, indicating that cable bacteria can rapidly transmit a geochemical effect to centimeters of depth in response to changing conditions at the sediment surface. We also observed a secondary response of the free sulfide at depth manifest on the time scale of hours, suggesting that cable bacteria adjust to a moving oxygen front with a regulatory or a behavioral response, such as motility. Finally, we show that on the time scale of days, the presence of an oxygenic biofilm results in a deeper and more acidic suboxic zone, indicating that a greater oxygen supply can enable cable bacteria to harvest a greater quantity of electrons from marine sediments. Rapid acclimation strategies and highly efficient electron harvesting are likely key advantages of cable bacteria, enabling their success in high sulfide generating coastal sediments.
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Dmytrenko O, Russell SL, Loo WT, Fontanez KM, Liao L, Roeselers G, Sharma R, Stewart FJ, Newton ILG, Woyke T, Wu D, Lang JM, Eisen JA, Cavanaugh CM. The genome of the intracellular bacterium of the coastal bivalve, Solemya velum: a blueprint for thriving in and out of symbiosis. BMC Genomics 2014; 15:924. [PMID: 25342549 PMCID: PMC4287430 DOI: 10.1186/1471-2164-15-924] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 09/23/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Symbioses between chemoautotrophic bacteria and marine invertebrates are rare examples of living systems that are virtually independent of photosynthetic primary production. These associations have evolved multiple times in marine habitats, such as deep-sea hydrothermal vents and reducing sediments, characterized by steep gradients of oxygen and reduced chemicals. Due to difficulties associated with maintaining these symbioses in the laboratory and culturing the symbiotic bacteria, studies of chemosynthetic symbioses rely heavily on culture independent methods. The symbiosis between the coastal bivalve, Solemya velum, and its intracellular symbiont is a model for chemosynthetic symbioses given its accessibility in intertidal environments and the ability to maintain it under laboratory conditions. To better understand this symbiosis, the genome of the S. velum endosymbiont was sequenced. RESULTS Relative to the genomes of obligate symbiotic bacteria, which commonly undergo erosion and reduction, the S. velum symbiont genome was large (2.7 Mb), GC-rich (51%), and contained a large number (78) of mobile genetic elements. Comparative genomics identified sets of genes specific to the chemosynthetic lifestyle and necessary to sustain the symbiosis. In addition, a number of inferred metabolic pathways and cellular processes, including heterotrophy, branched electron transport, and motility, suggested that besides the ability to function as an endosymbiont, the bacterium may have the capacity to live outside the host. CONCLUSIONS The physiological dexterity indicated by the genome substantially improves our understanding of the genetic and metabolic capabilities of the S. velum symbiont and the breadth of niches the partners may inhabit during their lifecycle.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Jonathan A Eisen
- Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, 4081 Biological Laboratories, Cambridge, MA 02138, USA.
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Lasken RS, McLean JS. Recent advances in genomic DNA sequencing of microbial species from single cells. Nat Rev Genet 2014; 15:577-84. [PMID: 25091868 PMCID: PMC4454502 DOI: 10.1038/nrg3785] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The vast majority of microbial species remain uncultivated and, until recently, about half of all known bacterial phyla were identified only from their 16S ribosomal RNA gene sequence. With the advent of single-cell sequencing, genomes of uncultivated species are rapidly filling in unsequenced branches of the microbial phylogenetic tree. The wealth of new insights gained from these previously inaccessible groups is providing a deeper understanding of their basic biology, taxonomy and evolution, as well as their diverse roles in environmental ecosystems and human health.
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Affiliation(s)
- Roger S Lasken
- J. Craig Venter Institute, 4120 Capricorn Lane, La Jolla, California 92037, USA
| | - Jeffrey S McLean
- 1] J. Craig Venter Institute, 4120 Capricorn Lane, La Jolla, California 92037, USA. [2] School of Dentistry, Department of Periodontics, University of Washington, Seattle, Washington 98195, USA
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Nunoura T, Takaki Y, Kazama H, Kakuta J, Shimamura S, Makita H, Hirai M, Miyazaki M, Takai K. Physiological and genomic features of a novel sulfur-oxidizing gammaproteobacterium belonging to a previously uncultivated symbiotic lineage isolated from a hydrothermal vent. PLoS One 2014; 9:e104959. [PMID: 25133584 PMCID: PMC4136832 DOI: 10.1371/journal.pone.0104959] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 07/15/2014] [Indexed: 12/04/2022] Open
Abstract
Strain Hiromi 1, a sulfur-oxidizing gammaproteobacterium was isolated from a hydrothermal vent chimney in the Okinawa Trough and represents a novel genus that may include a phylogenetic group found as endosymbionts of deep-sea gastropods. The SSU rRNA gene sequence similarity between strain Hiromi 1 and the gastropod endosymbionts was approximately 97%. The strain was shown to grow both chemolithoautotrophically and chemolithoheterotrophically with an energy metabolism of sulfur oxidation and O2 or nitrate reduction. Under chemolithoheterotrophic growth conditions, the strain utilized organic acids and proteinaceous compounds as the carbon and/or nitrogen sources but not the energy source. Various sugars did not support growth as a sole carbon source. The observation of chemolithoheterotrophy in this strain is in line with metagenomic analyses of endosymbionts suggesting the occurrence of chemolithoheterotrophy in gammaproteobacterial symbionts. Chemolithoheterotrophy and the presence of homologous genes for virulence- and quorum sensing-related functions suggest that the sulfur-oxidizing chomolithotrophic microbes seek animal bodies and microbial biofilm formation to obtain supplemental organic carbons in hydrothermal ecosystems.
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Affiliation(s)
- Takuro Nunoura
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
- * E-mail:
| | - Yoshihiro Takaki
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
| | - Hiromi Kazama
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
| | - Jungo Kakuta
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
| | - Shigeru Shimamura
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
| | - Hiroko Makita
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
| | - Miho Hirai
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
| | - Masayuki Miyazaki
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
| | - Ken Takai
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
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Boschker HTS, Vasquez-Cardenas D, Bolhuis H, Moerdijk-Poortvliet TWC, Moodley L. Chemoautotrophic carbon fixation rates and active bacterial communities in intertidal marine sediments. PLoS One 2014; 9:e101443. [PMID: 25003508 PMCID: PMC4086895 DOI: 10.1371/journal.pone.0101443] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 06/06/2014] [Indexed: 11/18/2022] Open
Abstract
Chemoautotrophy has been little studied in typical coastal marine sediments, but may be an important component of carbon recycling as intense anaerobic mineralization processes in these sediments lead to accumulation of high amounts of reduced compounds, such as sulfides and ammonium. We studied chemoautotrophy by measuring dark-fixation of 13C-bicarbonate into phospholipid derived fatty acid (PLFA) biomarkers at two coastal sediment sites with contrasting sulfur chemistry in the Eastern Scheldt estuary, the Netherlands. At one site where free sulfide accumulated in the pore water right to the top of the sediment, PLFA labeling was restricted to compounds typically found in sulfur and ammonium oxidizing bacteria. At the other site, with no detectable free sulfide in the pore water, a very different PLFA labeling pattern was found with high amounts of label in branched i- and a-PLFA besides the typical compounds for sulfur and ammonium oxidizing bacteria. This suggests that other types of chemoautotrophic bacteria were also active, most likely Deltaproteobacteria related to sulfate reducers. Maximum rates of chemoautotrophy were detected in first 1 to 2 centimeters of both sediments and chemosynthetic biomass production was high ranging from 3 to 36 mmol C m−2 d−1. Average dark carbon fixation to sediment oxygen uptake ratios were 0.22±0.07 mol C (mol O2)−1, which is in the range of the maximum growth yields reported for sulfur oxidizing bacteria indicating highly efficient growth. Chemoautotrophic biomass production was similar to carbon mineralization rates in the top of the free sulfide site, suggesting that chemoautotrophic bacteria could play a crucial role in the microbial food web and labeling in eukaryotic poly-unsaturated PLFA was indeed detectable. Our study shows that dark carbon fixation by chemoautotrophic bacteria is a major process in the carbon cycle of coastal sediments, and should therefore receive more attention in future studies on sediment biogeochemistry and microbial ecology.
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Affiliation(s)
- Henricus T. S. Boschker
- Department of Marine Microbiology, Royal Netherlands Institute for Sea Research (NIOZ), Yerseke, The Netherlands
- * E-mail:
| | - Diana Vasquez-Cardenas
- Department of Marine Microbiology, Royal Netherlands Institute for Sea Research (NIOZ), Yerseke, The Netherlands
| | - Henk Bolhuis
- Department of Marine Microbiology, Royal Netherlands Institute for Sea Research (NIOZ), Yerseke, The Netherlands
| | | | - Leon Moodley
- Marine Environment Group, International Research Institute of Stavanger (IRIS), Randaberg, Norway
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Genomic insights into the uncultured genus 'Candidatus Magnetobacterium' in the phylum Nitrospirae. ISME JOURNAL 2014; 8:2463-77. [PMID: 24914800 DOI: 10.1038/ismej.2014.94] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 04/27/2014] [Accepted: 05/08/2014] [Indexed: 11/09/2022]
Abstract
Magnetotactic bacteria (MTB) of the genus 'Candidatus Magnetobacterium' in phylum Nitrospirae are of great interest because of the formation of hundreds of bullet-shaped magnetite magnetosomes in multiple bundles of chains per cell. These bacteria are worldwide distributed in aquatic environments and have important roles in the biogeochemical cycles of iron and sulfur. However, except for a few short genomic fragments, no genome data are available for this ecologically important genus, and little is known about their metabolic capacity owing to the lack of pure cultures. Here we report the first draft genome sequence of 3.42 Mb from an uncultivated strain tentatively named 'Ca. Magnetobacterium casensis' isolated from Lake Miyun, China. The genome sequence indicates an autotrophic lifestyle using the Wood-Ljungdahl pathway for CO2 fixation, which has not been described in any previously known MTB or Nitrospirae organisms. Pathways involved in the denitrification, sulfur oxidation and sulfate reduction have been predicted, indicating its considerable capacity for adaptation to variable geochemical conditions and roles in local biogeochemical cycles. Moreover, we have identified a complete magnetosome gene island containing mam, mad and a set of novel genes (named as man genes) putatively responsible for the formation of bullet-shaped magnetite magnetosomes and the arrangement of multiple magnetosome chains. This first comprehensive genomic analysis sheds light on the physiology, ecology and biomineralization of the poorly understood 'Ca. Magnetobacterium' genus.
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-Biao Guo F, Lin Y, -Ling Chen L. Recognition of Protein-coding Genes Based on Z-curve Algorithms. Curr Genomics 2014; 15:95-103. [PMID: 24822027 PMCID: PMC4009845 DOI: 10.2174/1389202915999140328162724] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 11/19/2013] [Accepted: 11/20/2013] [Indexed: 01/18/2023] Open
Abstract
Recognition of protein-coding genes, a classical bioinformatics issue, is an absolutely needed step for annotating newly sequenced genomes. The Z-curve algorithm, as one of the most effective methods on this issue, has been successfully applied in annotating or re-annotating many genomes, including those of bacteria, archaea and viruses. Two Z-curve based ab initio gene-finding programs have been developed: ZCURVE (for bacteria and archaea) and ZCURVE_V (for viruses and phages). ZCURVE_C (for 57 bacteria) and Zfisher (for any bacterium) are web servers for re-annotation of bacterial and archaeal genomes. The above four tools can be used for genome annotation or re-annotation, either independently or combined with the other gene-finding programs. In addition to recognizing protein-coding genes and exons, Z-curve algorithms are also effective in recognizing promoters and translation start sites. Here, we summarize the applications of Z-curve algorithms in gene finding and genome annotation.
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Affiliation(s)
- Feng -Biao Guo
- Center of Bioinformatics and Key Laboratory for NeuroInformation of the Ministry of Education, University of Elec-tronic Science and Technology of China, Chengdu, 610054, China
| | - Yan Lin
- Department of Physics, Tianjin University, Tianjin 300072, China
| | - Ling -Ling Chen
- cCollege of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
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50
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Yu H, Chen C, Ma J, Xu X, Fan R, Wang A. Microbial community functional structure in response to micro-aerobic conditions in sulfate-reducing sulfur-producing bioreactor. J Environ Sci (China) 2014; 26:1099-1107. [PMID: 25079640 DOI: 10.1016/s1001-0742(13)60589-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 10/30/2013] [Accepted: 11/07/2013] [Indexed: 06/03/2023]
Abstract
Limited oxygen supply to anaerobic wastewater treatment systems had been demonstrated as an effective strategy to improve elemental sulfur (S(0)) recovery, coupling sulfate reduction and sulfide oxidation. However, little is known about the impact of dissolved oxygen (DO) on the microbial functional structures in these systems. We used a high throughput tool (GeoChip) to evaluate the microbial community structures in a biological desulfurization reactor under micro-aerobic conditions (DO: 0.02-0.33 mg/L). The results indicated that the microbial community functional compositions and structures were dramatically altered with elevated DO levels. The abundances of dsrA/B genes involved in sulfate reduction processes significantly decreased (p < 0.05, LSD test) at relatively high DO concentration (DO: 0.33 mg/L). The abundances of sox and fccA/B genes involved in sulfur/sulfide oxidation processes significantly increased (p < 0.05, LSD test) in low DO concentration conditions (DO: 0.09 mg/L) and then gradually decreased with continuously elevated DO levels. Their abundances coincided with the change of sulfate removal efficiencies and elemental sulfur (S(0)) conversion efficiencies in the bioreactor. In addition, the abundance of carbon degradation genes increased with the raising of DO levels, showing that the heterotrophic microorganisms (e.g., fermentative microorganisms) were thriving under micro-aerobic condition. This study provides new insights into the impacts of micro-aerobic conditions on the microbial functional structure of sulfate-reducing sulfur-producing bioreactors, and revealed the potential linkage between functional microbial communities and reactor performance.
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Affiliation(s)
- Hao Yu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; School of Environmental Science and Engineering, Liaoning Technical University, Fuxin 123000, China.
| | - Chuan Chen
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Jincai Ma
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Xijun Xu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Ronggui Fan
- School of Environmental Science and Engineering, Liaoning Technical University, Fuxin 123000, China
| | - Aijie Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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