101
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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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102
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Kawai S, Martinez JN, Lichtenberg M, Trampe E, Kühl M, Tank M, Haruta S, Nishihara A, Hanada S, Thiel V. In-Situ Metatranscriptomic Analyses Reveal the Metabolic Flexibility of the Thermophilic Anoxygenic Photosynthetic Bacterium Chloroflexus aggregans in a Hot Spring Cyanobacteria-Dominated Microbial Mat. Microorganisms 2021; 9:microorganisms9030652. [PMID: 33801086 PMCID: PMC8004040 DOI: 10.3390/microorganisms9030652] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/17/2021] [Accepted: 03/17/2021] [Indexed: 12/13/2022] Open
Abstract
Chloroflexus aggregans is a metabolically versatile, thermophilic, anoxygenic phototrophic member of the phylum Chloroflexota (formerly Chloroflexi), which can grow photoheterotrophically, photoautotrophically, chemoheterotrophically, and chemoautotrophically. In hot spring-associated microbial mats, C. aggregans co-exists with oxygenic cyanobacteria under dynamic micro-environmental conditions. To elucidate the predominant growth modes of C. aggregans, relative transcription levels of energy metabolism- and CO2 fixation-related genes were studied in Nakabusa Hot Springs microbial mats over a diel cycle and correlated with microscale in situ measurements of O2 and light. Metatranscriptomic analyses indicated two periods with different modes of energy metabolism of C. aggregans: (1) phototrophy around midday and (2) chemotrophy in the early morning hours. During midday, C. aggregans mainly employed photoheterotrophy when the microbial mats were hyperoxic (400–800 µmol L−1 O2). In the early morning hours, relative transcription peaks of genes encoding uptake hydrogenase, key enzymes for carbon fixation, respiratory complexes as well as enzymes for TCA cycle and acetate uptake suggest an aerobic chemomixotrophic lifestyle. This is the first in situ study of the versatile energy metabolism of C. aggregans based on gene transcription patterns. The results provide novel insights into the metabolic flexibility of these filamentous anoxygenic phototrophs that thrive under dynamic environmental conditions.
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Affiliation(s)
- Shigeru Kawai
- Department of Biological Sciences, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan; (J.N.M.); (M.T.); (S.H.); (A.N.); (S.H.)
- Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa 237-0061, Japan
- Correspondence: (S.K.); (V.T.)
| | - Joval N. Martinez
- Department of Biological Sciences, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan; (J.N.M.); (M.T.); (S.H.); (A.N.); (S.H.)
- Department of Natural Sciences, College of Arts and Sciences, University of St. La Salle, Bacolod City, Negros Occidental 6100, Philippines
| | - Mads Lichtenberg
- Department of Biology, Marine Biological Section, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør, Denmark; (M.L.); (E.T.); (M.K.)
| | - Erik Trampe
- Department of Biology, Marine Biological Section, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør, Denmark; (M.L.); (E.T.); (M.K.)
| | - Michael Kühl
- Department of Biology, Marine Biological Section, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør, Denmark; (M.L.); (E.T.); (M.K.)
| | - Marcus Tank
- Department of Biological Sciences, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan; (J.N.M.); (M.T.); (S.H.); (A.N.); (S.H.)
- DSMZ—German Culture Collection of Microorganisms and Cell Culture, GmbH Inhoffenstraße 7B, 38124 Braunschweig, Germany
| | - Shin Haruta
- Department of Biological Sciences, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan; (J.N.M.); (M.T.); (S.H.); (A.N.); (S.H.)
| | - Arisa Nishihara
- Department of Biological Sciences, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan; (J.N.M.); (M.T.); (S.H.); (A.N.); (S.H.)
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki 305-8566, Japan
| | - Satoshi Hanada
- Department of Biological Sciences, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan; (J.N.M.); (M.T.); (S.H.); (A.N.); (S.H.)
| | - Vera Thiel
- Department of Biological Sciences, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan; (J.N.M.); (M.T.); (S.H.); (A.N.); (S.H.)
- DSMZ—German Culture Collection of Microorganisms and Cell Culture, GmbH Inhoffenstraße 7B, 38124 Braunschweig, Germany
- Correspondence: (S.K.); (V.T.)
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103
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Tong H, Zheng C, Li B, Swanner ED, Liu C, Chen M, Xia Y, Liu Y, Ning Z, Li F, Feng X. Microaerophilic Oxidation of Fe(II) Coupled with Simultaneous Carbon Fixation and As(III) Oxidation and Sequestration in Karstic Paddy Soil. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:3634-3644. [PMID: 33411520 DOI: 10.1021/acs.est.0c05791] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Microaerophilic Fe(II)-oxidizing bacteria are often chemolithoautotrophs, and the Fe(III) (oxyhydr)oxides they form could immobilize arsenic (As). If such microbes are active in karstic paddy soils, their activity would help increase soil organic carbon and mitigate As contamination. We therefore used gel-stabilized gradient systems to cultivate microaerophilic Fe(II)-oxidizing bacteria from karstic paddy soil to investigate their capacity for Fe(II) oxidation, carbon fixation, and As sequestration. Stable isotope probing demonstrated the assimilation of inorganic carbon at a maximum rate of 8.02 mmol C m-2 d-1. Sequencing revealed that Bradyrhizobium, Cupriavidus, Hyphomicrobium, Kaistobacter, Mesorhizobium, Rhizobium, unclassified Phycisphaerales, and unclassified Opitutaceas were fixing carbon. Fe(II) oxidation produced Fe(III) (oxyhydr)oxides, which can absorb and/or coprecipitate As. Adding As(III) decreased the diversity of functional bacteria involved in carbon fixation, the relative abundance of predicted carbon fixation genes, and the amount of carbon fixed. Although the rate of Fe(II) oxidation was also lower in the presence of As(III), over 90% of the As(III) was sequestered after oxidation. The potential for microbially mediated As(III) oxidation was revealed by the presence of arsenite oxidase gene (aioA), denoting the potential of the Fe(II)-oxidizing and autotrophic microbial community to also oxidize As(III). Thisstudy demonstrates that carbon fixation coupled to Fe(II) oxidation can increase the carbon content in soils by microaerophilic Fe(II)-oxidizing bacteria, as well as accelerate As(III) oxidation and sequester it in association with Fe(III) (oxyhydr)oxides.
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Affiliation(s)
- Hui Tong
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou510650, China
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang550081, China
- Department of Geological and Atmospheric Sciences, Iowa State University, Ames50011, Iowa, United States
| | - Chunju Zheng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang550081, China
| | - Bing Li
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen518055, China
| | - Elizabeth D Swanner
- Department of Geological and Atmospheric Sciences, Iowa State University, Ames50011, Iowa, United States
| | - Chengshuai Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang550081, China
- CAS Center for Excellence in Quaternary Science and Global Change, Xi'an710061, China
| | - Manjia Chen
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou510650, China
| | - Yafei Xia
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang550081, China
| | - Yuhui Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang550081, China
| | - Zengping Ning
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang550081, China
| | - Fangbai Li
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou510650, China
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang550081, China
- CAS Center for Excellence in Quaternary Science and Global Change, Xi'an710061, China
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104
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The Autotrophic Core: An Ancient Network of 404 Reactions Converts H 2, CO 2, and NH 3 into Amino Acids, Bases, and Cofactors. Microorganisms 2021; 9:microorganisms9020458. [PMID: 33672143 PMCID: PMC7926472 DOI: 10.3390/microorganisms9020458] [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: 01/28/2021] [Revised: 02/11/2021] [Accepted: 02/19/2021] [Indexed: 01/03/2023] Open
Abstract
The metabolism of cells contains evidence reflecting the process by which they arose. Here, we have identified the ancient core of autotrophic metabolism encompassing 404 reactions that comprise the reaction network from H2, CO2, and ammonia (NH3) to amino acids, nucleic acid monomers, and the 19 cofactors required for their synthesis. Water is the most common reactant in the autotrophic core, indicating that the core arose in an aqueous environment. Seventy-seven core reactions involve the hydrolysis of high-energy phosphate bonds, furthermore suggesting the presence of a non-enzymatic and highly exergonic chemical reaction capable of continuously synthesizing activated phosphate bonds. CO2 is the most common carbon-containing compound in the core. An abundance of NADH and NADPH-dependent redox reactions in the autotrophic core, the central role of CO2, and the circumstance that the core’s main products are far more reduced than CO2 indicate that the core arose in a highly reducing environment. The chemical reactions of the autotrophic core suggest that it arose from H2, inorganic carbon, and NH3 in an aqueous environment marked by highly reducing and continuously far from equilibrium conditions. Such conditions are very similar to those found in serpentinizing hydrothermal systems.
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105
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Buhrman G, Enríquez P, Dillard L, Baer H, Truong V, Grunden AM, Rose RB. Structure, Function, and Thermal Adaptation of the Biotin Carboxylase Domain Dimer from Hydrogenobacter thermophilus 2-Oxoglutarate Carboxylase. Biochemistry 2021; 60:324-345. [PMID: 33464881 DOI: 10.1021/acs.biochem.0c00815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
2-Oxoglutarate carboxylase (OGC), a unique member of the biotin-dependent carboxylase family from the order Aquificales, captures dissolved CO2 via the reductive tricarboxylic acid (rTCA) cycle. Structure and function studies of OGC may facilitate adaptation of the rTCA cycle to increase the level of carbon fixation for biofuel production. Here we compare the biotin carboxylase (BC) domain of Hydrogenobacter thermophilus OGC with the well-studied mesophilic homologues to identify features that may contribute to thermal stability and activity. We report three OGC BC X-ray structures, each bound to bicarbonate, ADP, or ADP-Mg2+, and propose that substrate binding at high temperatures is facilitated by interactions that stabilize the flexible subdomain B in a partially closed conformation. Kinetic measurements with varying ATP and biotin concentrations distinguish two temperature-dependent steps, consistent with biotin's rate-limiting role in organizing the active site. Transition state thermodynamic values derived from the Eyring equation indicate a larger positive ΔH⧧ and a less negative ΔS⧧ compared to those of a previously reported mesophilic homologue. These thermodynamic values are explained by partially rate limiting product release. Phylogenetic analysis of BC domains suggests that OGC diverged prior to Aquificales evolution. The phylogenetic tree identifies mis-annotations of the Aquificales BC sequences, including the Aquifex aeolicus pyruvate carboxylase structure. Notably, our structural data reveal that the OGC BC dimer comprises a "wet" dimerization interface that is dominated by hydrophilic interactions and structural water molecules common to all BC domains and likely facilitates the conformational changes associated with the catalytic cycle. Mutations in the dimerization domain demonstrate that dimerization contributes to thermal stability.
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Affiliation(s)
- Greg Buhrman
- Department of Molecular & Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7622, United States
| | - Paul Enríquez
- Department of Molecular & Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7622, United States
| | - Lucas Dillard
- Department of Molecular & Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7622, United States
| | - Hayden Baer
- Department of Molecular & Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7622, United States
| | - Vivian Truong
- Department of Molecular & Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7622, United States
| | - Amy M Grunden
- Department of Plant & Microbial Biology, North Carolina State University, Raleigh, North Carolina 27695-7612, United States
| | - Robert B Rose
- Department of Molecular & Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7622, United States
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106
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Napieralski SA, Roden EE. The Weathering Microbiome of an Outcropping Granodiorite. Front Microbiol 2021; 11:601907. [PMID: 33381096 PMCID: PMC7767972 DOI: 10.3389/fmicb.2020.601907] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/26/2020] [Indexed: 11/13/2022] Open
Abstract
Microorganisms have long been recognized for their capacity to catalyze the weathering of silicate minerals. While the vast majority of studies on microbially mediated silicate weathering focus on organotrophic metabolism linked to nutrient acquisition, it has been recently demonstrated that chemolithotrophic ferrous iron [Fe(II)] oxidizing bacteria (FeOB) are capable of coupling the oxidation of silicate mineral Fe(II) to metabolic energy generation and cellular growth. In natural systems, complex microbial consortia with diverse metabolic capabilities can exist and interact to influence the biogeochemical cycling of essential elements, including iron. Here we combine microbiological and metagenomic analyses to investigate the potential interactions among metabolically diverse microorganisms in the near surface weathering of an outcrop of the Rio Blanco Quartz Diorite (DIO) in the Luquillo Mountains of Puerto Rico. Laboratory based incubations utilizing ground DIO as metabolic energy source for chemolithotrophic FeOB confirmed the ability of FeOB to grow via the oxidation of silicate-bound Fe(II). Dramatically accelerated rates of Fe(II)-oxidation were associated with an enrichment in microorganisms with the genetic capacity for iron oxidizing extracellular electron transfer (EET) pathways. Microbially oxidized DIO displayed an enhanced susceptibility to the weathering activity of organotrophic microorganisms compared to unoxidized mineral suspensions. Our results suggest that chemolithotrophic and organotrophic microorganisms are likely to coexist and contribute synergistically to the overall weathering of the in situ bedrock outcrop.
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Affiliation(s)
| | - Eric E Roden
- Department of Geoscience, University of Wisconsin-Madison, Madison, WI, United States
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107
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François DX, Godfroy A, Mathien C, Aubé J, Cathalot C, Lesongeur F, L'Haridon S, Philippon X, Roussel EG. Persephonella atlantica sp. nov.: How to adapt to physico-chemical gradients in high temperature hydrothermal habitats. Syst Appl Microbiol 2020; 44:126176. [PMID: 33422731 DOI: 10.1016/j.syapm.2020.126176] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/18/2020] [Accepted: 12/18/2020] [Indexed: 10/22/2022]
Abstract
A novel thermophilic, microaerophilic and anaerobic, hydrogen- sulphur- and thiosulphate-oxidising bacterium, designated MO1340T, was isolated from a deep-sea hydrothermal chimney collected from the Lucky Strike hydrothermal vent field on the Mid-Atlantic Ridge. Cells were short, motile rods of 1.4-2.2μm length and 0.5-0.8μm width. Optimal growth was observed for a NaCl concentration of 2.5 % (w/v) at pH 6.5. As for other members of the genus Persephonella, strain MO1340T was strictly chemolithoautotrophic and could oxidise hydrogen, elemental sulphur or thiosulphate using oxygen as electron acceptor. Anaerobic nitrate reduction using hydrogen could also be performed. Each catabolic reaction had a different optimal growth temperature (65 to 75°C) and an optimal dissolved oxygen concentration (11.4 to 119.7 μM at 70°C for aerobic reactions) that varied according to the electron donors utilised. These experimental results are consistent with the distribution of these catabolic substrates along the temperature gradient observed in active hydrothermal systems. They strongly suggest that this adaptive strategy could confer a selective advantage for strain MO1340T in the dynamic part of the ecosystem where hot, reduced hydrothermal fluid mixes with cold, oxygenated seawater. Phylogenetic analysis indicated that strain MO1340T was a member of the genus Persephonella within the order Hydrogenothermales as it shared a 16S rRNA gene sequence similarity <95.5 % and ANI respectively 75.66 % with closest described Persephonella (P. hydrogeniphila 29WT). On the basis of the physiological and genomic properties of the new isolate, the name Persephonella atlantica sp. nov. is proposed. The type strain is MO1340T (=UBOCC-M-3359T =JCM 34026T).
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Affiliation(s)
- David X François
- Univ Brest, Ifremer, CNRS, Laboratoire de Microbiologie des Environnements Extrêmes UMR6197, F-29280, Plouzané, France
| | - Anne Godfroy
- Univ Brest, Ifremer, CNRS, Laboratoire de Microbiologie des Environnements Extrêmes UMR6197, F-29280, Plouzané, France
| | - Clémentine Mathien
- Univ Brest, Ifremer, CNRS, Laboratoire de Microbiologie des Environnements Extrêmes UMR6197, F-29280, Plouzané, France
| | - Johanne Aubé
- Univ Brest, Ifremer, CNRS, Laboratoire de Microbiologie des Environnements Extrêmes UMR6197, F-29280, Plouzané, France
| | - Cécile Cathalot
- Ifremer, Laboratoire Cycle Géochimique et Ressources (LCG/GM/REM), F-29280, Plouzané, France
| | - Françoise Lesongeur
- Univ Brest, Ifremer, CNRS, Laboratoire de Microbiologie des Environnements Extrêmes UMR6197, F-29280, Plouzané, France
| | - Stéphane L'Haridon
- Univ Brest, Ifremer, CNRS, Laboratoire de Microbiologie des Environnements Extrêmes UMR6197, F-29280, Plouzané, France
| | - Xavier Philippon
- Univ Brest, Ifremer, CNRS, Laboratoire de Microbiologie des Environnements Extrêmes UMR6197, F-29280, Plouzané, France
| | - Erwan G Roussel
- Univ Brest, Ifremer, CNRS, Laboratoire de Microbiologie des Environnements Extrêmes UMR6197, F-29280, Plouzané, France.
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108
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Jing H, Wang R, Jiang Q, Zhang Y, Peng X. Anaerobic methane oxidation coupled to denitrification is an important potential methane sink in deep-sea cold seeps. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 748:142459. [PMID: 33113688 DOI: 10.1016/j.scitotenv.2020.142459] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 09/13/2020] [Accepted: 09/13/2020] [Indexed: 06/11/2023]
Abstract
Microbes play a crucial role in mediating the methane flux in deep-sea cold seep ecosystems, where only methane-related microbes have been well studied, while the whole microbial community and their ecological functions were still largely unknown. Here, we utilized metagenomic data to investigate how the structure and metabolism of microbial community shift in the reduced sediment habitats along the spatial scales. Microbial communities in cold seeps and troughs formed two distinct clades likely driven by environmental factors, such as total sulfur, total phosphate and NO3-, rather than geographical proximity. The predominance of Methanosarcinales reflected a high potential for methane production. In addition to the already well-reported ANME-1/SRB consortia, prevalence of bacterial Methylomirabilis and archaeal Methanoperedens as important performers in the n-damo process with respective of nitrite and nitrate as respective electron acceptor was observed in deep-sea hydrate-bearing regions as well. Aerobic methane oxidization was conducted mainly by type I methanotrophs at Site F (Formosa Ridge), but also via the n-damo process by Methanoperedens and Methylomirabilis in the Haima seep and Xisha Trough, respectively. Based on the high abundance of those denitrifying-dependent methane oxidizers and their related functional genes, we concluded that the previously overlooked n-damo process might be a major methane sink in cold seeps or in gas hydrate-bearing sediments if nitrate is available in the anoxic zones. The signature of isotopic labeling would be essential to confirm the contribution of different anaerobic methane oxidizing pathways in deep-sea cold seep ecosystems.
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Affiliation(s)
- Hongmei Jing
- CAS Key Laboratory for Experimental Study under Deep-sea Extreme Conditions, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China; Southern Marine Science and Engineering Guangdong Laboratory, ZhuHai, China.
| | - Ruonan Wang
- CAS Key Laboratory for Experimental Study under Deep-sea Extreme Conditions, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
| | - Qiuyun Jiang
- CAS Key Laboratory for Experimental Study under Deep-sea Extreme Conditions, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
| | - Yue Zhang
- CAS Key Laboratory for Experimental Study under Deep-sea Extreme Conditions, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
| | - Xiaotong Peng
- CAS Key Laboratory for Experimental Study under Deep-sea Extreme Conditions, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.
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109
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Sun X, Yang J, Zheng M, Zhang X. Artificial construction of the biocoenosis of deep-sea ecosystem via seeping methane. Environ Microbiol 2020; 23:1186-1198. [PMID: 33283960 DOI: 10.1111/1462-2920.15347] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 12/02/2020] [Indexed: 11/30/2022]
Abstract
Deep-sea ecosystems, such as cold seeps and hydrothermal vents, have high biomass, even though they are located in the benthic zone, where no sunlight is present to provide energy for organism proliferation. Based on the coexistence of the reduced gases and chemoautotrophic microbes, it is inferred that the energy from the reduced gases supports the biocoenosis of deep-sea ecosystems. However, there is no direct evidence to support this deduction. Here, we developed and placed a biocoenosis generator, a device that continuously seeped methane, on the 1000-m deep-sea floor of the South China Sea to artificially construct a deep-sea ecosystem biocoenosis. The results showed that microorganisms, including bacteria and archaea, appeared in the biocoenosis generator first, followed by jellyfish and Gammaridea arthropods, indicating that a biocoenosis had been successfully constructed in the deep sea. Anaerobic methane-oxidizing archaea, which shared characteristics with the archaea of natural deep-sea cold seeps, acted as the first electron acceptors of the emitted methane; then, the energy in the electrons was transferred to downstream symbiotic archaea and bacteria and finally to animals. Nitrate-reducing bacteria served as partners to complete anaerobic oxidation of methane process. Further analysis revealed that viruses coexisted with these organisms during the origin of the deep-sea biocoenosis. Therefore, our study mimics a natural deep-sea ecosystem and provides the direct evidence to show that the chemical energy of reduced organic molecules, such as methane, supports the biocoenosis of deep-sea ecosystems.
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Affiliation(s)
- Xumei Sun
- College of Life Sciences, Laboratory for Marine Biology and Biotechnology of Pilot National Laboratory for Marine Science and Technology (Qingdao) and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhejiang University, Hangzhou, 310058, China
| | - Junyi Yang
- School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou, 310018, China
| | - Minhui Zheng
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, 310012, China
| | - Xiaobo Zhang
- College of Life Sciences, Laboratory for Marine Biology and Biotechnology of Pilot National Laboratory for Marine Science and Technology (Qingdao) and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhejiang University, Hangzhou, 310058, China
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110
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Sánchez-García L, Carrizo D, Molina A, Muñoz-Iglesias V, Lezcano MÁ, Fernández-Sampedro M, Parro V, Prieto-Ballesteros O. Fingerprinting molecular and isotopic biosignatures on different hydrothermal scenarios of Iceland, an acidic and sulfur-rich Mars analog. Sci Rep 2020; 10:21196. [PMID: 33273669 PMCID: PMC7712778 DOI: 10.1038/s41598-020-78240-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 11/23/2020] [Indexed: 11/09/2022] Open
Abstract
Detecting signs of potential extant/extinct life on Mars is challenging because the presence of organics on that planet is expected to be very low and most likely linked to radiation-protected refugia and/or preservative strategies (e.g., organo-mineral complexes). With scarcity of organics, accounting for biomineralization and potential relationships between biomarkers, mineralogy, and geochemistry is key in the search for extraterrestrial life. Here we explored microbial fingerprints and their associated mineralogy in Icelandic hydrothermal systems analog to Mars (i.e., high sulfur content, or amorphous silica), to identify potentially habitable locations on that planet. The mineralogical assemblage of four hydrothermal substrates (hot springs biofilms, mud pots, and steaming and inactive fumaroles) was analyzed concerning the distribution of biomarkers. Molecular and isotopic composition of lipids revealed quantitative and compositional differences apparently impacted by surface geothermal alteration and environmental factors. pH and water showed an influence (i.e., greatest biomass in circumneutral settings with highest supply and turnover of water), whereas temperature conditioned the mineralogy that supported specific microbial metabolisms related with sulfur. Raman spectra suggested the possible coexistence of abiotic and biomediated sources of minerals (i.e., sulfur or hematite). These findings may help to interpret future Raman or GC-MS signals in forthcoming Martian missions.
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Affiliation(s)
| | - Daniel Carrizo
- Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir km 4, Madrid, Spain
| | - Antonio Molina
- Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir km 4, Madrid, Spain
| | | | | | | | - Victor Parro
- Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir km 4, Madrid, Spain
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111
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Seto M, Iwasa Y. How Thermodynamics Illuminates Population Interactions in Microbial Communities. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.602809] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In traditional population models of microbial ecology, there are two central players: producers and consumers (including decomposers that depend on organic carbon). Producers support surface ecosystems by generating adenosine triphosphate (ATP) from sunlight, part of which is used to build new biomass from carbon dioxide. In contrast, the productivity of subsurface ecosystems with a limited supply of sunlight must rely on bacteria and archaea that are able generate ATP solely from chemical or electric energy to fix inorganic carbon. These “light-independent producers” are frequently not included in traditional food webs, even though they are ubiquitous in nature and interact with one another through the utilization of the by-products of others. In this review, we introduce theoretical approaches based on population dynamics that incorporate thermodynamics to highlight characteristic interactions in the microbial community of subsurface ecosystems, which may link community structures and ecosystem expansion under conditions of a limited supply of sunlight. In comparison with light-dependent producers, which compete with one another for light, the use of Gibbs free energy (chemical energy) can lead cooperative interactions among light-independent producers through the effects of the relative quantities of products and reactants on the available chemical energy, which is termed abundant resource premium. The development of a population theory that incorporates thermodynamics offers fundamental ecological insights into subsurface microbial ecosystems, which may be applied to fields of study such as environmental science/engineering, astrobiology, or the microbial ecosystems of the early earth.
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112
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Coutinho FH, Cabello-Yeves PJ, Gonzalez-Serrano R, Rosselli R, López-Pérez M, Zemskaya TI, Zakharenko AS, Ivanov VG, Rodriguez-Valera F. New viral biogeochemical roles revealed through metagenomic analysis of Lake Baikal. MICROBIOME 2020; 8:163. [PMID: 33213521 PMCID: PMC7678222 DOI: 10.1186/s40168-020-00936-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 10/12/2020] [Indexed: 05/05/2023]
Abstract
BACKGROUND Lake Baikal is the largest body of liquid freshwater on Earth. Previous studies have described the microbial composition of this habitat, but the viral communities from this ecosystem have not been characterized in detail. RESULTS Here, we describe the viral diversity of this habitat across depth and seasonal gradients. We discovered 19,475 bona fide viral sequences, which are derived from viruses predicted to infect abundant and ecologically important taxa that reside in Lake Baikal, such as Nitrospirota, Methylophilaceae, and Crenarchaeota. Diversity analysis revealed significant changes in viral community composition between epipelagic and bathypelagic zones. Analysis of the gene content of individual viral populations allowed us to describe one of the first bacteriophages that infect Nitrospirota, and their extensive repertoire of auxiliary metabolic genes that might enhance carbon fixation through the reductive TCA cycle. We also described bacteriophages of methylotrophic bacteria with the potential to enhance methanol oxidation and the S-adenosyl-L-methionine cycle. CONCLUSIONS These findings unraveled new ways by which viruses influence the carbon cycle in freshwater ecosystems, namely, by using auxiliary metabolic genes that act upon metabolisms of dark carbon fixation and methylotrophy. Therefore, our results shed light on the processes through which viruses can impact biogeochemical cycles of major ecological relevance. Video Abstract.
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Affiliation(s)
- F H Coutinho
- Evolutionary Genomics Group, Dpto. Producción Vegetal y Microbiología, Universidad Miguel Hernández, Aptdo. 18., Ctra. Alicante-Valencia N-332, s/n, San Juan de Alicante, 03550, Alicante, Spain.
| | - P J Cabello-Yeves
- Evolutionary Genomics Group, Dpto. Producción Vegetal y Microbiología, Universidad Miguel Hernández, Aptdo. 18., Ctra. Alicante-Valencia N-332, s/n, San Juan de Alicante, 03550, Alicante, Spain
| | - R Gonzalez-Serrano
- Evolutionary Genomics Group, Dpto. Producción Vegetal y Microbiología, Universidad Miguel Hernández, Aptdo. 18., Ctra. Alicante-Valencia N-332, s/n, San Juan de Alicante, 03550, Alicante, Spain
| | - R Rosselli
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, Den Burg, The Netherlands
- Utrecht University, Utrecht, The Netherlands
| | - M López-Pérez
- Evolutionary Genomics Group, Dpto. Producción Vegetal y Microbiología, Universidad Miguel Hernández, Aptdo. 18., Ctra. Alicante-Valencia N-332, s/n, San Juan de Alicante, 03550, Alicante, Spain
| | - T I Zemskaya
- Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia
| | - A S Zakharenko
- Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia
| | - V G Ivanov
- Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia
| | - F Rodriguez-Valera
- Evolutionary Genomics Group, Dpto. Producción Vegetal y Microbiología, Universidad Miguel Hernández, Aptdo. 18., Ctra. Alicante-Valencia N-332, s/n, San Juan de Alicante, 03550, Alicante, Spain
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
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113
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Sun X, Qiu L, Kolton M, Häggblom M, Xu R, Kong T, Gao P, Li B, Jiang C, Sun W. V V Reduction by Polaromonas spp. in Vanadium Mine Tailings. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:14442-14454. [PMID: 33125214 DOI: 10.1021/acs.est.0c05328] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Vanadium (V) is an important metal with critical industrial and medical applications. Elevated V contamination, however, can be a threat to the environment and human health. Microorganisms can reduce the more toxic and mobile VV to the less toxic and immobile VIV, which could be a detoxification and energy metabolism strategy adopted by V-reducing bacteria (VRB). The limited understanding of microbial responses to V contamination and the mechanisms for VV reduction, however, hamper our capability to attenuate V contamination. This study focused on determining the microbial responses to elevated V concentration and the mechanisms of VV reduction in V tailings. The bacterial communities were characterized and compared between the V tailings and the less contaminated adjacent mineral soils. Further, VV-reducing enrichments indicated that bacteria associated with Polaromonas, a genus belonging to the family Burkholderiaceae, were potentially responsible for VV reduction. Retrieved metagenome-assembled genomes (MAGs) suggested that the Polaromonas spp. encoded genes (cymA, omcA, and narG) were responsible for VV reduction. Additionally, Polaromonas spp. was metabolically versatile and could use both organic and inorganic electron donors. The metabolic versatility of Polaromonas spp. may be important for its ability to flourish in the V tailings.
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Affiliation(s)
- Xiaoxu Sun
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
| | - Lang Qiu
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
| | - Max Kolton
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
| | - Max Häggblom
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey 08901, United States
| | - Rui Xu
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
| | - Tianle Kong
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
| | - Pin Gao
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
| | - Baoqin Li
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
| | - Chengjian Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Weimin Sun
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
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Satanowski A, Dronsella B, Noor E, Vögeli B, He H, Wichmann P, Erb TJ, Lindner SN, Bar-Even A. Awakening a latent carbon fixation cycle in Escherichia coli. Nat Commun 2020; 11:5812. [PMID: 33199707 PMCID: PMC7669889 DOI: 10.1038/s41467-020-19564-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 10/15/2020] [Indexed: 02/06/2023] Open
Abstract
Carbon fixation is one of the most important biochemical processes. Most natural carbon fixation pathways are thought to have emerged from enzymes that originally performed other metabolic tasks. Can we recreate the emergence of a carbon fixation pathway in a heterotrophic host by recruiting only endogenous enzymes? In this study, we address this question by systematically analyzing possible carbon fixation pathways composed only of Escherichia coli native enzymes. We identify the GED (Gnd-Entner-Doudoroff) cycle as the simplest pathway that can operate with high thermodynamic driving force. This autocatalytic route is based on reductive carboxylation of ribulose 5-phosphate (Ru5P) by 6-phosphogluconate dehydrogenase (Gnd), followed by reactions of the Entner-Doudoroff pathway, gluconeogenesis, and the pentose phosphate pathway. We demonstrate the in vivo feasibility of this new-to-nature pathway by constructing E. coli gene deletion strains whose growth on pentose sugars depends on the GED shunt, a linear variant of the GED cycle which does not require the regeneration of Ru5P. Several metabolic adaptations, most importantly the increased production of NADPH, assist in establishing sufficiently high flux to sustain this growth. Our study exemplifies a trajectory for the emergence of carbon fixation in a heterotrophic organism and demonstrates a synthetic pathway of biotechnological interest.
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Affiliation(s)
- Ari Satanowski
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Beau Dronsella
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Elad Noor
- Institute of Molecular Systems Biology, ETH Zürich, Otto-Stern-Weg 3, 8093, Zürich, Switzerland
| | - Bastian Vögeli
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Straße 10, 35043, Marburg, Germany
| | - Hai He
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Philipp Wichmann
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Tobias J Erb
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Straße 10, 35043, Marburg, Germany.,Center for Synthetic Microbiology (SYNMIKRO), 35043, Marburg, Germany
| | - Steffen N Lindner
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany.
| | - Arren Bar-Even
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany
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115
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Campbell MA, Grice K, Visscher PT, Morris T, Wong HL, White RA, Burns BP, Coolen MJL. Functional Gene Expression in Shark Bay Hypersaline Microbial Mats: Adaptive Responses. Front Microbiol 2020; 11:560336. [PMID: 33312167 PMCID: PMC7702295 DOI: 10.3389/fmicb.2020.560336] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 10/09/2020] [Indexed: 11/25/2022] Open
Abstract
Microbial mat communities possess extensive taxonomic and functional diversity, which drive high metabolic rates and rapid cycling of major elements. Modern microbial mats occurring in hypersaline environments are considered as analogs to extinct geobiological formations dating back to ∼ 3.5 Gyr ago. Despite efforts to understand the diversity and metabolic potential of hypersaline microbial mats in Shark Bay, Western Australia, there has yet to be molecular analyses at the transcriptional level in these microbial communities. In this study, we generated metatranscriptomes for the first time from actively growing mats comparing the type of mat, as well as the influence of diel and seasonal cycles. We observed that the overall gene transcription is strongly influenced by microbial community structure and seasonality. The most transcribed genes were associated with tackling the low nutrient conditions by the uptake of fatty acids, phosphorus, iron, and nickel from the environment as well as with protective mechanisms against elevated salinity conditions and to prevent build-up of ammonium produced by nitrate reducing microorganisms. A range of pathways involved in carbon, nitrogen, and sulfur cycles were identified in mat metatranscriptomes, with anoxygenic photosynthesis and chemoautotrophy using the Arnon–Buchanan cycle inferred as major pathways involved in the carbon cycle. Furthermore, enrichment of active anaerobic pathways (e.g., sulfate reduction, methanogenesis, Wood–Ljungdahl) in smooth mats corroborates previous metagenomic studies and further advocates the potential of these communities as modern analogs of ancient microbialites.
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Affiliation(s)
- Matthew A Campbell
- WA-Organic Isotope Geochemistry Centre, The Institute for Geoscience Research, School of Earth and Planetary Sciences, Curtin University, Perth, WA, Australia
| | - Kliti Grice
- WA-Organic Isotope Geochemistry Centre, The Institute for Geoscience Research, School of Earth and Planetary Sciences, Curtin University, Perth, WA, Australia
| | - Pieter T Visscher
- Departments of Marine Sciences and Geoscience, University of Connecticut, Storrs, CT, United States.,Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, Australia
| | - Therese Morris
- Applied Geology, Curtin University, Perth, WA, Australia
| | - Hon Lun Wong
- Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, Australia.,School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Richard Allen White
- Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, Australia.,Plant Pathology, Washington State University, Pullman, WA, United States.,RAW Molecular Systems (RMS) LLC, Spokane, WA, United States
| | - Brendan P Burns
- Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, Australia.,School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Marco J L Coolen
- WA-Organic Isotope Geochemistry Centre, The Institute for Geoscience Research, School of Earth and Planetary Sciences, Curtin University, Perth, WA, Australia
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116
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Moopantakath J, Imchen M, Siddhardha B, Kumavath R. 16s rRNA metagenomic analysis reveals predominance of Crtl and CruF genes in Arabian Sea coast of India. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 743:140699. [PMID: 32679495 DOI: 10.1016/j.scitotenv.2020.140699] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 06/25/2020] [Accepted: 07/01/2020] [Indexed: 06/11/2023]
Abstract
Microbial communities perform crucial biogeochemical cycles in distinct ecosystems. Halophilic microbial communities are enriched in the saline areas. Hence, haloarchaea have been primarily studied in salterns and marine biosystems with the aim to harness haloarcheal carotenoids biosynthesis. In this study, sediment from several distinct biosystems (mangrove, seashore, estuary, river, lake, salt pan and island) across the Arabian coastal region of India were collected and analyzed though 16s rRNA metagenomic and whole genome approach to elucidated the dominant representative genre, haloarcheal diversity, and the prevalence of Crtl and CruF genes. We found that the microbial diversity in mangrove sediment (794 OTUs) was highest and lowest in lake and river (558-560 OTUs). Moreover, the bacterial domain dominated in all biosystems (96.00-99.45%). Top 10 abundant genera were involved in biochemical cycles such as sulfur, methane, ammonia, hydrocarbon degradation, and antibiotics production. The Archaea was mainly composed of Haloarchaea, Methanobacteria, Methanococci, Methanomicrobia and Crenarchaeota. Carotenoid gene, Crtl, was observed in a major portion (abundance 60%; diversity 45%) of microbial community. Interestingly, we found that all species under haloarcheal class that were represented in fresh as well as marine biosystems encodes CruF gene (bacterioruberin carotenoid). Our study demonstrates the high microbial diversity in various ecosystems, enrichment of Crtl gene, and also shows that Crtl and CruF genes are highly abundant in haloarcheal genera. The finding of ecosystems specific Crtl and CruF encoding genera opens up a promising area in bioprospecting the carotenoid derivatives from the wide range of natural biosystems.
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Affiliation(s)
- Jamseel Moopantakath
- Department of Genomic Science, Central University of Kerala, Tejaswini Hills, Periya, Kasaragod 671320, Kerala, India
| | - Madangchanok Imchen
- Department of Genomic Science, Central University of Kerala, Tejaswini Hills, Periya, Kasaragod 671320, Kerala, India
| | - Busi Siddhardha
- Department of Microbiology, School of Life Sciences, Pondicherry University, Puducherry 605014, India
| | - Ranjith Kumavath
- Department of Genomic Science, Central University of Kerala, Tejaswini Hills, Periya, Kasaragod 671320, Kerala, India.
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Park SJ, Andrei AŞ, Bulzu PA, Kavagutti VS, Ghai R, Mosier AC. Expanded Diversity and Metabolic Versatility of Marine Nitrite-Oxidizing Bacteria Revealed by Cultivation- and Genomics-Based Approaches. Appl Environ Microbiol 2020; 86:e01667-20. [PMID: 32917751 PMCID: PMC7642081 DOI: 10.1128/aem.01667-20] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 09/03/2020] [Indexed: 12/30/2022] Open
Abstract
Nitrite-oxidizing bacteria (NOB) are ubiquitous and abundant microorganisms that play key roles in global nitrogen and carbon biogeochemical cycling. Despite recent advances in understanding NOB physiology and taxonomy, currently very few cultured NOB or representative NOB genome sequences from marine environments exist. In this study, we employed enrichment culturing and genomic approaches to shed light on the phylogeny and metabolic capacity of marine NOB. We successfully enriched two marine NOB (designated MSP and DJ) and obtained a high-quality metagenome-assembled genome (MAG) from each organism. The maximum nitrite oxidation rates of the MSP and DJ enrichment cultures were 13.8 and 30.0 μM nitrite per day, respectively, with these optimum rates occurring at 0.1 mM and 0.3 mM nitrite, respectively. Each enrichment culture exhibited a different tolerance to various nitrite and salt concentrations. Based on phylogenomic position and overall genome relatedness indices, both NOB MAGs were proposed as novel taxa within the Nitrospinota and Nitrospirota phyla. Functional predictions indicated that both NOB MAGs shared many highly conserved metabolic features with other NOB. Both NOB MAGs encoded proteins for hydrogen and organic compound metabolism and defense mechanisms for oxidative stress. Additionally, these organisms may have the genetic potential to produce cobalamin (an essential enzyme cofactor that is limiting in many environments) and, thus, may play an important role in recycling cobalamin in marine sediment. Overall, this study appreciably expands our understanding of the Nitrospinota and Nitrospirota phyla and suggests that these NOB play important biogeochemical roles in marine habitats.IMPORTANCE Nitrification is a key process in the biogeochemical and global nitrogen cycle. Nitrite-oxidizing bacteria (NOB) perform the second step of aerobic nitrification (converting nitrite to nitrate), which is critical for transferring nitrogen to other organisms for assimilation or energy. Despite their ecological importance, there are few cultured or genomic representatives from marine systems. Here, we obtained two NOB (designated MSP and DJ) enriched from marine sediments and estimated the physiological and genomic traits of these marine microbes. Both NOB enrichment cultures exhibit distinct responses to various nitrite and salt concentrations. Genomic analyses suggest that these NOB are metabolically flexible (similar to other previously described NOB) yet also have individual genomic differences that likely support distinct niche distribution. In conclusion, this study provides more insights into the ecological roles of NOB in marine environments.
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Affiliation(s)
- Soo-Je Park
- Department of Biology, Jeju National University, Jeju, Republic of Korea
| | - Adrian-Ştefan Andrei
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Paul-Adrian Bulzu
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Vinicius S Kavagutti
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
- Department of Ecosystem Biology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Rohit Ghai
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Annika C Mosier
- Department of Integrative Biology, University of Colorado Denver, Denver, Colorado, USA
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Metatranscriptomics by
In Situ
RNA Stabilization Directly and Comprehensively Revealed Episymbiotic Microbial Communities of Deep-Sea Squat Lobsters. mSystems 2020; 5:5/5/e00551-20. [PMID: 33024051 PMCID: PMC8534475 DOI: 10.1128/msystems.00551-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Shinkaia crosnieri is an invertebrate that inhabits an area around deep-sea hydrothermal vents in the Okinawa Trough in Japan by harboring episymbiotic microbes as the primary nutrition. To reveal physiology and phylogenetic composition of the active episymbiotic populations, metatranscriptomics is expected to be a powerful approach. However, this has been hindered by substantial perturbation (e.g., RNA degradation) during time-consuming retrieval from the deep sea. Here, we conducted direct metatranscriptomic analysis of S. crosnieri episymbionts by applying in situ RNA stabilization equipment. As expected, we obtained RNA expression profiles that were substantially different from those obtained by conventional metatranscriptomics (i.e., stabilization after retrieval). The episymbiotic community members were dominated by three orders, namely, Thiotrichales, Methylococcales, and Campylobacterales, and the Campylobacterales members were mostly dominated by the Sulfurovum genus. At a finer phylogenetic scale, the episymbiotic communities on different host individuals shared many species, indicating that the episymbionts on each host individual are not descendants of a few founder cells but are horizontally exchanged. Furthermore, our analysis revealed the key metabolisms of the community: two carbon fixation pathways, a formaldehyde assimilation pathway, and utilization of five electron donors (sulfide, thiosulfate, sulfur, methane, and ammonia) and two electron accepters (oxygen and nitrate/nitrite). Importantly, it was suggested that Thiotrichales episymbionts can utilize intercellular sulfur globules even when sulfur compounds are not usable, possibly also in a detached and free-living state. IMPORTANCE Deep-sea hydrothermal vent ecosystems remain mysterious. To depict in detail the enigmatic life of chemosynthetic microbes, which are key primary producers in these ecosystems, metatranscriptomic analysis is expected to be a promising approach. However, this has been hindered by substantial perturbation (e.g., RNA degradation) during time-consuming retrieval from the deep sea. In this study, we conducted direct metatranscriptome analysis of microbial episymbionts of deep-sea squat lobsters (Shinkaia crosnieri) by applying in situ RNA stabilization equipment. Compared to conventional metatranscriptomics (i.e., RNA stabilization after retrieval), our method provided substantially different RNA expression profiles. Moreover, we discovered that S. crosnieri and its episymbiotic microbes constitute complex and resilient ecosystems, where closely related but various episymbionts are stably maintained by horizontal exchange and partly by their sulfur storage ability for survival even when sulfur compounds are not usable, likely also in a detached and free-living state.
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119
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Martin WF. Carbon-Metal Bonds: Rare and Primordial in Metabolism. Trends Biochem Sci 2020; 44:807-818. [PMID: 31104860 DOI: 10.1016/j.tibs.2019.04.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/16/2019] [Accepted: 04/18/2019] [Indexed: 12/13/2022]
Abstract
Submarine hydrothermal vents are rich in hydrogen (H2), an ancient source of electrons and chemical energy for life. Geochemical H2 stems from serpentinization, a process in which rock-bound iron reduces water to H2. Reactions involving H2 and carbon dioxide (CO2) in hydrothermal systems generate abiotic methane and formate; these reactions resemble the core energy metabolism of methanogens and acetogens. These organisms are strict anaerobic autotrophs that inhabit hydrothermal vents and harness energy via H2-dependent CO2 reduction. Serpentinization also generates native metals, which can reduce CO2 to formate and acetate in the laboratory. The enzymes that channel H2, CO2, and dinitrogen (N2) into methanogen and acetogen metabolism are the backbone of the most ancient metabolic pathways. Their active sites share carbon-metal bonds which, although rare in biology, are conserved relics of primordial biochemistry present at the origin of life.
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Affiliation(s)
- William F Martin
- Institute for Molecular Evolution, University of Düsseldorf, 40225 Düsseldorf, Germany.
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Wong HL, MacLeod FI, White RA, Visscher PT, Burns BP. Microbial dark matter filling the niche in hypersaline microbial mats. MICROBIOME 2020; 8:135. [PMID: 32938503 PMCID: PMC7495880 DOI: 10.1186/s40168-020-00910-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 08/19/2020] [Indexed: 05/08/2023]
Abstract
BACKGROUND Shark Bay, Australia, harbours one of the most extensive and diverse systems of living microbial mats that are proposed to be analogs of some of the earliest ecosystems on Earth. These ecosystems have been shown to possess a substantial abundance of uncultivable microorganisms. These enigmatic microbes, jointly coined as 'microbial dark matter' (MDM), are hypothesised to play key roles in modern microbial mats. RESULTS We reconstructed 115 metagenome-assembled genomes (MAGs) affiliated to MDM, spanning 42 phyla. This study reports for the first time novel microorganisms (Zixibacterial order GN15) putatively taking part in dissimilatory sulfate reduction in surface hypersaline settings, as well as novel eukaryote signature proteins in the Asgard archaea. Despite possessing reduced-size genomes, the MDM MAGs are capable of fermenting and degrading organic carbon, suggesting a role in recycling organic carbon. Several forms of RuBisCo were identified, allowing putative CO2 incorporation into nucleotide salvaging pathways, which may act as an alternative carbon and phosphorus source. High capacity of hydrogen production was found among Shark Bay MDM. Putative schizorhodopsins were also identified in Parcubacteria, Asgard archaea, DPANN archaea, and Bathyarchaeota, allowing these members to potentially capture light energy. Diversity-generating retroelements were prominent in DPANN archaea that likely facilitate the adaptation to a dynamic, host-dependent lifestyle. CONCLUSIONS This is the first study to reconstruct and describe in detail metagenome-assembled genomes (MAGs) affiliated with microbial dark matter in hypersaline microbial mats. Our data suggests that these microbial groups are major players in these systems. In light of our findings, we propose H2, ribose and CO/CO2 as the main energy currencies of the MDM community in these mat systems. Video Abstract.
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Affiliation(s)
- Hon Lun Wong
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, Australia
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia
| | - Fraser I MacLeod
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, Australia
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia
| | - Richard Allen White
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia
- RAW Molecular Systems LLC, Spokane, WA, USA
- Department of Bioinformatics and Genomics, The University of North Carolina, Charlotte, NC, USA
| | - Pieter T Visscher
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia
- Department of Marine Sciences, University of Connecticut, Mansfield, USA
- Biogeosciences, the Université de Bourgogne Franche-Comté, Dijon, France
| | - Brendan P Burns
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, Australia.
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia.
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Sun X, Xu R, Dong Y, Li F, Tao W, Kong T, Zhang M, Qiu L, Wang X, Sun W. Investigation of the Ecological Roles of Putative Keystone Taxa during Tailing Revegetation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:11258-11270. [PMID: 32786562 DOI: 10.1021/acs.est.0c03031] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Metal contamination released from tailings is a global environmental concern. Although phytoremediation is a promising remediation method, its practice is often impeded by the adverse tailing geochemical conditions, which suppress biological activities. The ecosystem services provided by indigenous microorganisms could alter environmental conditions and facilitate revegetation in tailings. During the process, the keystone taxa of the microbial community are assumed an essential role in regulating the community composition and functions. The identity and the environmental functions of the keystone taxa during tailing revegetation, however, remain unelucidated. The current study compared the microbial community composition and interactions of two contrasting stibnite (Sb2S3) tailings, one revegetated and one unvegetated. The microbial interaction networks and keystone taxa were significantly different in the two tailings. Similar keystone taxa were also identified in other revegetated tailings, but not in their corresponding unvegetated tailings. Metagenome-assembled genomes (MAGs) indicated that the keystone taxa in the revegetated tailing may use both organic and inorganic energy sources (e.g., sulfur, arsenic, and antimony). They could also facilitate plant growth since a number of plant-growth-promoting genes, including phosphorus solubilization and siderophore production genes, were encoded. The current study suggests that keystone taxa may play important roles in tailing revegetation by providing nutrients, such as P and Fe, and promoting plant growth.
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Affiliation(s)
- Xiaoxu Sun
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
| | - Rui Xu
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
| | - Yiran Dong
- School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan 430074, China
| | - Fangbai Li
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
| | - Wan Tao
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
| | - Tianle Kong
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
| | - Miaomiao Zhang
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
| | - Lang Qiu
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
| | - Xiaoyu Wang
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
| | - Weimin Sun
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
- Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510650, China
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Singh A, Nylander JAA, Schnürer A, Bongcam-Rudloff E, Müller B. High-Throughput Sequencing and Unsupervised Analysis of Formyltetrahydrofolate Synthetase (FTHFS) Gene Amplicons to Estimate Acetogenic Community Structure. Front Microbiol 2020; 11:2066. [PMID: 32983047 PMCID: PMC7481360 DOI: 10.3389/fmicb.2020.02066] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 08/05/2020] [Indexed: 11/17/2022] Open
Abstract
The formyltetrahydrofolate synthetase (FTHFS) gene is a molecular marker of choice to study the diversity of acetogenic communities. However, current analyses are limited due to lack of a high-throughput sequencing approach for FTHFS gene amplicons and a dedicated bioinformatics pipeline for data analysis, including taxonomic annotation and visualization of the sequence data. In the present study, we combined the barcode approach for multiplexed sequencing with unsupervised data analysis to visualize acetogenic community structure. We used samples from a biogas digester to develop proof-of-principle for our combined approach. We successfully generated high-throughput sequence data for the partial FTHFS gene and performed unsupervised data analysis using the novel bioinformatics pipeline “AcetoScan” presented in this study, which resulted in taxonomically annotated OTUs, phylogenetic tree, abundance plots and diversity indices. The results demonstrated that high-throughput sequencing can be used to sequence the FTHFS amplicons from a pool of samples, while the analysis pipeline AcetoScan can be reliably used to process the raw sequence data and visualize acetogenic community structure. The method and analysis pipeline described in this paper can assist in the identification and quantification of known or potentially new acetogens. The AcetoScan pipeline is freely available at https://github.com/abhijeetsingh1704/AcetoScan.
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Affiliation(s)
- Abhijeet Singh
- Anaerobic Microbiology and Biotechnology Group, Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Johan A A Nylander
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden.,National Bioinformatics Infrastructure Sweden, SciLifeLab, Uppsala, Sweden
| | - Anna Schnürer
- Anaerobic Microbiology and Biotechnology Group, Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Erik Bongcam-Rudloff
- SLU-Global Bioinformatics Centre, Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Bettina Müller
- Anaerobic Microbiology and Biotechnology Group, Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Bayer K, Busch K, Kenchington E, Beazley L, Franzenburg S, Michels J, Hentschel U, Slaby BM. Microbial Strategies for Survival in the Glass Sponge Vazella pourtalesii. mSystems 2020; 5:e00473-20. [PMID: 32788407 PMCID: PMC7426153 DOI: 10.1128/msystems.00473-20] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 07/23/2020] [Indexed: 01/04/2023] Open
Abstract
Few studies have explored the microbiomes of glass sponges (Hexactinellida). The present study seeks to elucidate the composition of the microbiota associated with the glass sponge Vazella pourtalesii and the functional strategies of the main symbionts. We combined microscopic approaches with metagenome-guided microbial genome reconstruction and amplicon community profiling toward this goal. Microscopic imaging revealed that the host and microbial cells appeared within dense biomass patches that are presumably syncytial tissue aggregates. Based on abundances in amplicon libraries and metagenomic data, SAR324 bacteria, Crenarchaeota, Patescibacteria, and Nanoarchaeota were identified as abundant members of the V. pourtalesii microbiome; thus, their genomic potentials were analyzed in detail. A general pattern emerged in that the V. pourtalesii symbionts had very small genome sizes, in the range of 0.5 to 2.2 Mb, and low GC contents, even below those of seawater relatives. Based on functional analyses of metagenome-assembled genomes (MAGs), we propose two major microbial strategies: the "givers," namely, Crenarchaeota and SAR324, heterotrophs and facultative anaerobes, produce and partly secrete all required amino acids and vitamins. The "takers," Nanoarchaeota and Patescibacteria, are anaerobes with reduced genomes that tap into the microbial community for resources, e.g., lipids and DNA, likely using pilus-like structures. We posit that the existence of microbial cells in sponge syncytia together with the low-oxygen conditions in the seawater environment are factors that shape the unique compositional and functional properties of the microbial community associated with V. pourtalesii IMPORTANCE We investigated the microbial community of V. pourtalesii that forms globally unique, monospecific sponge grounds under low-oxygen conditions on the Scotian Shelf, where it plays a key role in its vulnerable ecosystem. The microbial community was found to be concentrated within biomass patches and is dominated by small cells (<1 μm). MAG analyses showed consistently small genome sizes and low GC contents, which is unusual compared to known sponge symbionts. These properties, as well as the (facultatively) anaerobic metabolism and a high degree of interdependence between the dominant symbionts regarding amino acid and vitamin synthesis, are likely adaptations to the unique conditions within the syncytial tissue of their hexactinellid host and the low-oxygen environment.
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Affiliation(s)
- Kristina Bayer
- GEOMAR Helmholtz Centre for Ocean Research Kiel, RD3 Marine Symbioses, Kiel, Germany
| | - Kathrin Busch
- GEOMAR Helmholtz Centre for Ocean Research Kiel, RD3 Marine Symbioses, Kiel, Germany
| | - Ellen Kenchington
- Department of Fisheries and Oceans, Bedford Institute of Oceanography, Dartmouth, Nova Scotia, Canada
| | - Lindsay Beazley
- Department of Fisheries and Oceans, Bedford Institute of Oceanography, Dartmouth, Nova Scotia, Canada
| | - Sören Franzenburg
- Institute for Clinical Molecular Biology, Kiel University, Kiel, Germany
| | - Jan Michels
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany
| | - Ute Hentschel
- GEOMAR Helmholtz Centre for Ocean Research Kiel, RD3 Marine Symbioses, Kiel, Germany
- Kiel University, Kiel, Germany
| | - Beate M Slaby
- GEOMAR Helmholtz Centre for Ocean Research Kiel, RD3 Marine Symbioses, Kiel, Germany
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Murie KA, Bourdeau PE. Fragmented kelp forest canopies retain their ability to alter local seawater chemistry. Sci Rep 2020; 10:11939. [PMID: 32686725 PMCID: PMC7371639 DOI: 10.1038/s41598-020-68841-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 06/25/2020] [Indexed: 11/15/2022] Open
Abstract
Kelp forests support some of the most productive and diverse ecosystems on Earth, and their ability to uptake dissolved inorganic carbon (DIC) allows them to modify local seawater chemistry, creating gradients in carbon, pH, and oxygen in their vicinity. By taking up both bicarbonate and CO2 as a carbon source for photosynthesis, kelp forests can act as carbon sinks, reducing nearby acidity and increasing dissolved oxygen; creating conditions conducive to calcification. Recent stressors, however, have reduced kelp forest canopies globally; converting once large and persistent forests to fragmented landscapes of small kelp patches. In a two-year study, we determined whether fragmented kelp patches retained the ability to alter local seawater chemistry. We found that diel fluctuations of multiple parameters of carbonate chemistry were greater in the kelp canopy than in the kelp benthos and in adjacent urchin barrens, consistent with metabolic activity by the kelp. Further, kelp fragments increased pH and aragonite saturation and decreased pCO2 during the day to a similar degree as large, intact kelp forests. We conclude that small kelp patches could mitigate OA stress and serve as spatial and temporal refugia for canopy-dwelling organisms, though this effect is temporary and confined to daylight hours during the growing season.
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Affiliation(s)
- Kindall A Murie
- Telonicher Marine Laboratory, Humboldt State University, Trinidad, USA.
- Department of Biological Sciences, Humboldt State University, Arcata, USA.
| | - Paul E Bourdeau
- Telonicher Marine Laboratory, Humboldt State University, Trinidad, USA
- Department of Biological Sciences, Humboldt State University, Arcata, USA
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Methou P, Michel LN, Segonzac M, Cambon-Bonavita MA, Pradillon F. Integrative taxonomy revisits the ontogeny and trophic niches of Rimicaris vent shrimps. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200837. [PMID: 32874664 PMCID: PMC7428246 DOI: 10.1098/rsos.200837] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
Among hydrothermal vent species, Rimicaris exoculata is one of the most emblematic, hosting abundant and diverse ectosymbioses that provide most of its nutrition. Rimicaris exoculata co-occurs in dense aggregates with the much less abundant Rimicaris chacei in many Mid-Atlantic Ridge vent fields. This second shrimp also houses ectosymbiotic microorganisms but has a mixotrophic diet. Recent observations have suggested potential misidentifications between these species at their juvenile stages, which could have led to misinterpretations of their early-life ecology. Here, we confirm erroneous identification of the earliest stages and propose a new set of morphological characters unambiguously identifying juveniles of each species. On the basis of this reassessment, combined use of C, N and S stable isotope ratios reveals distinct ontogenic trophic niche shifts in both species, from photosynthesis-based nutrition before settlement, towards a chemosynthetic diet afterwards. Furthermore, isotopic compositions in the earliest juvenile stages suggest differences in larval histories. Each species thus exhibits specific early-life strategies that would, without our re-examination, have been interpreted as ontogenetic variations. Overall, our results provide a good illustration of the identification issues persisting in deep-sea ecosystems and the importance of integrative taxonomy in providing an accurate view of fundamental aspects of the biology and ecology of species inhabiting these environments.
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Affiliation(s)
- Pierre Methou
- Ifremer, Univ Brest, CNRS, Laboratoire de Microbiologie des Environnements Extrêmes, UMR 6197, F-29280 Plouzané, France
- Ifremer, Centre Brest, Laboratoire Environnement Profond (REM/EEP/LEP), ZI de la pointe du Diable, F-29280 Plouzané, France
| | - Loïc N. Michel
- Ifremer, Centre Brest, Laboratoire Environnement Profond (REM/EEP/LEP), ZI de la pointe du Diable, F-29280 Plouzané, France
| | - Michel Segonzac
- Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, case postale 53, 57 rue Cuvier, F-75231 Paris cedex 05, France
| | - Marie-Anne Cambon-Bonavita
- Ifremer, Univ Brest, CNRS, Laboratoire de Microbiologie des Environnements Extrêmes, UMR 6197, F-29280 Plouzané, France
| | - Florence Pradillon
- Ifremer, Centre Brest, Laboratoire Environnement Profond (REM/EEP/LEP), ZI de la pointe du Diable, F-29280 Plouzané, France
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Kawai S, Nishihara A, Matsuura K, Haruta S. Hydrogen-dependent autotrophic growth in phototrophic and chemolithotrophic cultures of thermophilic bacteria, Chloroflexus aggregans and Chloroflexus aurantiacus, isolated from Nakabusa hot springs. FEMS Microbiol Lett 2020; 366:5510454. [PMID: 31158281 DOI: 10.1093/femsle/fnz122] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 06/01/2019] [Indexed: 11/14/2022] Open
Abstract
The genus Chloroflexus is a deeply branching group of thermophilic filamentous anoxygenic phototrophic bacteria. The bacteria in this genus have been shown to grow well heterotrophically under anaerobic photosynthetic and aerobic respiratory conditions. We examined autotrophic growth in new isolates of Chloroflexus strains from hot springs in Nakabusa, Japan. The isolates belonging to Chloroflexus aggregans (98.7% identity of 16S rRNA gene sequence to the respective type strain) and Chloroflexus aurantiacus (99.9% identity to the respective type strain) grew photoautotrophically under a 24% H2 atmosphere. We also observed chemolithotrophic growth of these isolates under 80% H2 and 5% O2 conditions in the dark. This is the first report showing that Chloroflexus grew under both photoautotrophic and chemolithotrophic conditions in addition to photoheterotrophic and aerobic chemoheterotrophic conditions.
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Affiliation(s)
- Shigeru Kawai
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Arisa Nishihara
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Katsumi Matsuura
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Shin Haruta
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
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Smythers AL, McConnell EW, Lewis HC, Mubarek SN, Hicks LM. Photosynthetic Metabolism and Nitrogen Reshuffling Are Regulated by Reversible Cysteine Thiol Oxidation Following Nitrogen Deprivation in Chlamydomonas. PLANTS 2020; 9:plants9060784. [PMID: 32585825 PMCID: PMC7355495 DOI: 10.3390/plants9060784] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/01/2020] [Accepted: 06/19/2020] [Indexed: 12/13/2022]
Abstract
As global temperatures climb to historic highs, the far-reaching effects of climate change have impacted agricultural nutrient availability. This has extended to low latitude oceans, where a deficit in both nitrogen and phosphorus stores has led to dramatic decreases in carbon sequestration in oceanic phytoplankton. Although Chlamydomonas reinhardtii, a freshwater model green alga, has shown drastic systems-level alterations following nitrogen deprivation, the mechanisms through which these alterations are triggered and regulated are not fully understood. This study examined the role of reversible oxidative signaling in the nitrogen stress response of C. reinhardtii. Using oxidized cysteine resin-assisted capture enrichment coupled with label-free quantitative proteomics, 7889 unique oxidized cysteine thiol identifiers were quantified, with 231 significantly changing peptides from 184 proteins following 2 h of nitrogen deprivation. These results demonstrate that the cellular response to nitrogen assimilation, photosynthesis, pigment biosynthesis, and lipid metabolism are regulated by reversible oxidation. An enhanced role of non-damaging oxidative pathways is observed throughout the photosynthetic apparatus that provides a framework for further analysis in phototrophs.
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128
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Martin WF. Older Than Genes: The Acetyl CoA Pathway and Origins. Front Microbiol 2020; 11:817. [PMID: 32655499 PMCID: PMC7325901 DOI: 10.3389/fmicb.2020.00817] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 04/06/2020] [Indexed: 11/13/2022] Open
Abstract
For decades, microbiologists have viewed the acetyl CoA pathway and organisms that use it for H2-dependent carbon and energy metabolism, acetogens and methanogens, as ancient. Classical evidence and newer evidence indicating the antiquity of the acetyl CoA pathway are summarized here. The acetyl CoA pathway requires approximately 10 enzymes, roughly as many organic cofactors, and more than 500 kDa of combined subunit molecular mass to catalyze the conversion of H2 and CO2 to formate, acetate, and pyruvate in acetogens and methanogens. However, a single hydrothermal vent alloy, awaruite (Ni3Fe), can convert H2 and CO2 to formate, acetate, and pyruvate under mild hydrothermal conditions on its own. The chemical reactions of H2 and CO2 to pyruvate thus have a natural tendency to occur without enzymes, given suitable inorganic catalysts. This suggests that the evolution of the enzymatic acetyl CoA pathway was preceded by-and patterned along-a route of naturally occurring exergonic reactions catalyzed by transition metal minerals that could activate H2 and CO2 by chemisorption. The principle of forward (autotrophic) pathway evolution from preexisting non-enzymatic reactions is generalized to the concept of patterned evolution of pathways. In acetogens, exergonic reduction of CO2 by H2 generates acyl phosphates by highly reactive carbonyl groups undergoing attack by inert inorganic phosphate. In that ancient reaction of biochemical energy conservation, the energy behind formation of the acyl phosphate bond resides in the carbonyl, not in phosphate. The antiquity of the acetyl CoA pathway is usually seen in light of CO2 fixation; its role in primordial energy coupling via acyl phosphates and substrate-level phosphorylation is emphasized here.
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Affiliation(s)
- William F. Martin
- Institute for Molecular Evolution, University of Düsseldorf, Düsseldorf, Germany
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Ruiz‐Fernández P, Ramírez‐Flandes S, Rodríguez‐León E, Ulloa O. Autotrophic carbon fixation pathways along the redox gradient in oxygen-depleted oceanic waters. ENVIRONMENTAL MICROBIOLOGY REPORTS 2020; 12:334-341. [PMID: 32202395 PMCID: PMC7318340 DOI: 10.1111/1758-2229.12837] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 03/12/2020] [Accepted: 03/18/2020] [Indexed: 05/25/2023]
Abstract
Anoxic marine zones (AMZs), also known as 'oxygen-deficient zones', contribute to the loss of fixed nitrogen from the ocean by anaerobic microbial processes. While these microbial processes associated with the nitrogen cycle have been extensively studied, those linked to the carbon cycle in AMZs have received much less attention, particularly the autotrophic carbon fixation - a crucial component of the carbon cycle. Using metagenomic and metatranscriptomic data from major AMZs, we report an explicit partitioning of the marker genes associated with different autotrophic carbon fixation pathways along the redox gradient (from oxic to anoxic conditions) present in the water column of AMZs. Sequences related to the Calvin-Benson-Bassham cycle were found along the entire gradient, while those related to the reductive Acetyl-CoA pathway were restricted to suboxic and anoxic waters. Sequences putatively associated with the 3-hydroxypropionate/4-hydroxybutyrate cycle dominated in the upper and lower oxyclines. Genes related to the reductive tricarboxylic acid cycle were represented from dysoxic to anoxic waters. The taxonomic affiliation of the sequences is consistent with the presence of microorganisms involved in crucial steps of biogeochemical cycles in AMZs, such as the gamma-proteobacteria sulfur oxidisers, the anammox bacteria Candidatus Scalindua and the thaumarcheota ammonia oxidisers of the Marine Group I.
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Affiliation(s)
- Paula Ruiz‐Fernández
- Departamento de Oceanografía, Universidad de ConcepciónCasilla 160‐C, ConcepciónChile
- Instituto Milenio de OceanografíaCasilla 1313, ConcepciónChile
- Programade Postgrados en Oceanografía, Departamento de OceanografíaUniversidad de Concepción, Casilla 160‐C, ConcepciónChile
| | - Salvador Ramírez‐Flandes
- Departamento de Oceanografía, Universidad de ConcepciónCasilla 160‐C, ConcepciónChile
- Instituto Milenio de OceanografíaCasilla 1313, ConcepciónChile
| | | | - Osvaldo Ulloa
- Departamento de Oceanografía, Universidad de ConcepciónCasilla 160‐C, ConcepciónChile
- Instituto Milenio de OceanografíaCasilla 1313, ConcepciónChile
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130
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Zhang T, Shi XC, Ding R, Xu K, Tremblay PL. The hidden chemolithoautotrophic metabolism of Geobacter sulfurreducens uncovered by adaptation to formate. ISME JOURNAL 2020; 14:2078-2089. [PMID: 32398660 DOI: 10.1038/s41396-020-0673-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 04/24/2020] [Accepted: 04/29/2020] [Indexed: 02/01/2023]
Abstract
Multiple Fe(III)-reducing Geobacter species including the model Geobacter sulfurreducens are thought to be incapable of carbon dioxide fixation. The discovery of the reversed oxidative tricarboxylic acid cycle (roTCA) for CO2 reduction with citrate synthase as key enzyme raises the possibility that G. sulfurreducens harbors the metabolic potential for chemolithoautotrophic growth. We investigate this hypothesis by transferring G. sulfurreducens PCA serially with Fe(III) as electron acceptor and formate as electron donor and carbon source. The evolved strain T17-3 grew chemolithoautotrophically with a 2.7-fold population increase over 48 h and a Fe(III) reduction rate of 417.5 μM h-1. T17-3 also grew with CO2 as carbon source. Mutations in T17-3 and enzymatic assays point to an adaptation process where the succinyl-CoA synthetase, which is inactive in the wild-type, became active to complete the roTCA cycle. Deletion of the genes coding for the succinyl-CoA synthetase in T17-3 prevented growth with formate as substrate. Enzymatic assays also showed that the citrate synthase can perform the necessary cleavage of citrate for the functional roTCA cycle. These results demonstrate that G. sulfurreducens after adaptation reduced CO2 via the roTCA cycle. This previously hidden metabolism can be harnessed for biotechnological applications and suggests hidden ecological functions for Geobacter.
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Affiliation(s)
- Tian Zhang
- State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, 430070, PR China. .,School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, PR China. .,School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan, 430070, PR China.
| | - Xiao-Chen Shi
- State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, 430070, PR China.,School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, PR China.,School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan, 430070, PR China
| | - Ran Ding
- State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, 430070, PR China.,School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan, 430070, PR China
| | - Kai Xu
- Center for Material Research and Analysis, Wuhan University of Technology, Wuhan, 430070, PR China
| | - Pier-Luc Tremblay
- State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, 430070, PR China. .,School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan, 430070, PR China.
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131
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Laming SR, Hourdez S, Cambon-Bonavita MA, Pradillon F. Classical and computed tomographic anatomical analyses in a not-so-cryptic Alviniconcha species complex from hydrothermal vents in the SW Pacific. Front Zool 2020; 17:12. [PMID: 32391066 PMCID: PMC7203863 DOI: 10.1186/s12983-020-00357-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 03/16/2020] [Indexed: 01/21/2023] Open
Abstract
The chemosymbiotic gastropod Alviniconcha (Provannidae), first described in 1988, is one of the most emblematic hydrothermal-vent taxa described from the Central Indian Ridge and the Southwest (SW) Pacific. Symbiotic bacteria found in the gill of Alviniconcha are thought to be their principal source of nutrition. In the SW Pacific, species distributions for A. kojimai, A. boucheti - and to a lesser extent A. strummeri - overlap. While Alviniconcha species do not appear to truly co-exist in these highly energetic but spatially limited habitats, certain species regularly co-occur within a single vent field and in rare instances, the same edifice. Past research suggests that SW-Pacific Alviniconcha species might aggregate around fluids with distinct geothermal profiles. These small-scale distribution patterns have been attributed to differences in their symbiont assemblages or host physiologies. However, little is known about the anatomy of most Alviniconcha species, beyond that detailed for the type species Alviniconcha hessleri, whose geographic range does not overlap with other congeners. In fact, species within this genus are currently described as cryptic, despite the absence of any comparative morphological studies to assess this. To test whether the genus is genuinely cryptic and identify any functional differences in host anatomy that might also mediate habitat partitioning in SW Pacific species, the current study examined the morphoanatomy of A. kojimai, A. boucheti and A. strummeri from the Fatu Kapa vent field, an area of hydrothermal activity recently discovered north of the Lau Basin near the Wallis and Futuna Islands and the only known example where all three species occur within adjacent vent fields. A combination of detailed dissections, histology and X-ray computed tomography demonstrate that A. kojimai, A. strummeri and A. boucheti are readily identifiable based on shell morphology and ornamentation alone, and therefore not truly cryptic. These traits provide a rapid and reliable means for species identification. However, aside from some subtle differences in radular morphology, these species of Alviniconcha exhibit conserved anatomical features, providing no evidence that functional host anatomy is implicated in habitat partitioning. This provides support for the current belief that host-species distributions are probably governed by symbiont-mediated physiological factors.
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Affiliation(s)
- Sven R Laming
- 1Ifremer, Laboratoire Environnement Profond (REM/EEP/LEP), Plouzané, France.,2Ifremer, Univ Brest, CNRS, UMR6197, Laboratoire de Microbiologie des Environnements Extrêmes (REM/EEP/LM2E), Plouzané, France.,3Current address: LEME, CESAM - Centre for Environmental and Marine Studies, Department of Biology, Universidade de Aveiro, Santiago Campus, 3810-193 Aveiro, Portugal
| | - Stéphane Hourdez
- 4UMR 8222 CNRS-Sorbonne Université, Laboratoire d'écogéochimie des environnements benthiques (LECOB), Banyuls-sur-Mer, France
| | - Marie-Anne Cambon-Bonavita
- 2Ifremer, Univ Brest, CNRS, UMR6197, Laboratoire de Microbiologie des Environnements Extrêmes (REM/EEP/LM2E), Plouzané, France
| | - Florence Pradillon
- 1Ifremer, Laboratoire Environnement Profond (REM/EEP/LEP), Plouzané, France
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132
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Sun W, Sun X, Li B, Xu R, Young LY, Dong Y, Zhang M, Kong T, Xiao E, Wang Q. Bacterial response to sharp geochemical gradients caused by acid mine drainage intrusion in a terrace: Relevance of C, N, and S cycling and metal resistance. ENVIRONMENT INTERNATIONAL 2020; 138:105601. [PMID: 32120058 DOI: 10.1016/j.envint.2020.105601] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/10/2020] [Accepted: 02/19/2020] [Indexed: 06/10/2023]
Abstract
A unique terrace with sharp gradient of environmental conditions was selected to study the microbial response and survival strategies to the extreme environments introduced by acid mine drainage (AMD) contamination. A combination of geochemical analyses, metagenomic sequencing, ex-situ microcosm setups, and statistical analyses were used to investigate the environment-microbe interactions. The microbial communities and metabolic potentials along the terrace were studied by focusing on the genes associated with important biogeochemical processes (i.e., C, N, S cycling and metal resistance). Results show that the variations of geochemical parameters substantially shaped the indigenous microbial communities. Sharp environmental gradients also impacted the microbial metabolic potentials, especially for C, N, and S cycling. Although the relative abundances of carbon fixing genes did not significantly vary along the environmental gradients, the taxa for carbon fixation varied significantly in more contaminated fields versus less contaminated fields, indicating the effects of AMD contamination on the autotrophic microbial communities. AMD input also influenced the N cycling, especially for nitrogen fixation and dissimilatory nitrate reduction to ammonium (DNRA). In addition, ex situ experiments were undertaken to evaluate the effects of AMD contamination on nitrogen fixation rates. Random Forest (RF) analysis indicated that nitrate, pH, total N, TOC exhibited positive correlations with the rates of nitrogen fixation while total Fe, Fe(III), and sulfate showed negative effects. Two co-occurrence networks at taxonomic and genomic levels indicated that geochemical parameters such as pH, TOC, total N, total S, and total Fe substantially influenced the innate microbial communities and their metabolic potentials. The current study provides an understanding for microbial response to AMD contamination and lays the foundation for future potential AMD bioremediation.
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Affiliation(s)
- Weimin Sun
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, Guangzhou 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou 510650, China.
| | - Xiaoxu Sun
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, Guangzhou 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou 510650, China
| | - Baoqin Li
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, Guangzhou 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou 510650, China
| | - Rui Xu
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, Guangzhou 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou 510650, China
| | - Lily Y Young
- Department of Environmental Sciences, Rutgers University, New Brunswick 08540, USA
| | - Yiran Dong
- School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan 430074, China
| | - Miaomiao Zhang
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, Guangzhou 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou 510650, China
| | - Tianle Kong
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, Guangzhou 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou 510650, China
| | - Enzong Xiao
- Innovation Center and Key Laboratory of Waters Safety & Protection in the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou 510006, China
| | - Qi Wang
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, Guangzhou 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou 510650, China
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133
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Engelberts JP, Robbins SJ, de Goeij JM, Aranda M, Bell SC, Webster NS. Characterization of a sponge microbiome using an integrative genome-centric approach. THE ISME JOURNAL 2020; 14:1100-1110. [PMID: 31992859 PMCID: PMC7174397 DOI: 10.1038/s41396-020-0591-9] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 01/08/2020] [Accepted: 01/16/2020] [Indexed: 11/09/2022]
Abstract
Marine sponges often host diverse and species-specific communities of microorganisms that are critical for host health. Previous functional genomic investigations of the sponge microbiome have focused primarily on specific symbiont lineages, which frequently make up only a small fraction of the overall community. Here, we undertook genome-centric analysis of the symbiont community in the model species Ircinia ramosa and analyzed 259 unique, high-quality metagenome-assembled genomes (MAGs) that comprised 74% of the I. ramosa microbiome. Addition of these MAGs to genome trees containing all publicly available microbial sponge symbionts increased phylogenetic diversity by 32% within the archaea and 41% within the bacteria. Metabolic reconstruction of the MAGs showed extensive redundancy across taxa for pathways involved in carbon fixation, B-vitamin synthesis, taurine metabolism, sulfite oxidation, and most steps of nitrogen metabolism. Through the acquisition of all major taxa present within the I. ramosa microbiome, we were able to analyze the functional potential of a sponge-associated microbial community in unprecedented detail. Critical functions, such as carbon fixation, which had previously only been assigned to a restricted set of sponge-associated organisms, were actually spread across diverse symbiont taxa, whereas other essential pathways, such as ammonia oxidation, were confined to specific keystone taxa.
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Affiliation(s)
- J Pamela Engelberts
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Steven J Robbins
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Jasper M de Goeij
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Manuel Aranda
- Red Sea Research Center, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Sara C Bell
- Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Nicole S Webster
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.
- Australian Institute of Marine Science, Townsville, QLD, Australia.
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134
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Inaba S, Sakai H, Kato H, Horiuchi T, Yano H, Ohtsubo Y, Tsuda M, Nagata Y. Expression of an alcohol dehydrogenase gene in a heterotrophic bacterium induces carbon dioxide-dependent high-yield growth under oligotrophic conditions. MICROBIOLOGY-SGM 2020; 166:531-545. [PMID: 32310743 DOI: 10.1099/mic.0.000908] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Sphingobium japonicum strain UT26, whose γ-hexachlorocyclohexane-degrading ability has been studied in detail, is a typical aerobic and heterotrophic bacterium that needs organic carbon sources for its growth, and cannot grow on a minimal salt agar medium prepared without adding any organic carbon sources. Here, we isolated a mutant of UT26 with the ability to grow to visible state on such an oligotrophic medium from a transposon-induced mutant library. This high-yield growth under oligotrophic conditions (HYGO) phenotype was CO2-dependent and accompanied with CO2 incorporation. In the HYGO mutant, a transposon was inserted just upstream of the putative Zn-dependent alcohol dehydrogenase (ADH) gene (adhX) so that the adhX gene was constitutively expressed, probably by the transposon-derived promoter. The adhX-deletion mutant (UT26DAX) harbouring a plasmid carrying the adhX gene under the control of a constitutive promoter exhibited the HYGO phenotype. Moreover, the HYGO mutants spontaneously emerged among the UT26-derived hypermutator strain cells, and adhX was highly expressed in these HYGO mutants, while no HYGO mutant appeared among UT26DAX-derived hypermutator strain cells, indicating the necessity of adhX for the HYGO phenotype. His-tagged AdhX that was expressed in Escherichia coli and purified to homogeneity showed ADH activity towards methanol and other alcohols. Mutagenesis analysis of the adhX gene indicated a correlation between the ADH activity and the HYGO phenotype. These results demonstrated that the constitutive expression of an adhX-encoding protein with ADH activity in UT26 leads to the CO2-dependent HYGO phenotype. Identical or nearly identical adhX orthologues were found in other sphingomonad strains, and most of them were located on plasmids, suggesting that the adhX-mediated HYGO phenotype may be an important adaptation strategy to oligotrophic environments among sphingomonads.
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Affiliation(s)
- Shinnosuke Inaba
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Hironori Sakai
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Hiromi Kato
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Takayuki Horiuchi
- Chitose Laboratory Corp., 2-13-3 Nogawa-honcho, Miyamae-ku, Kawasaki, Kanagawa, 216-0041, Japan
| | - Hirokazu Yano
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Yoshiyuki Ohtsubo
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Masataka Tsuda
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Yuji Nagata
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
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135
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A Possible Primordial Acetyleno/Carboxydotrophic Core Metabolism. Life (Basel) 2020; 10:life10040035. [PMID: 32272667 PMCID: PMC7235995 DOI: 10.3390/life10040035] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/03/2020] [Accepted: 04/04/2020] [Indexed: 12/04/2022] Open
Abstract
Carbon fixation, in addition to the evolution of metabolism, is a main requirement for the evolution of life. Here, we report a one-pot carbon fixation of acetylene (C2H2) and carbon monoxide (CO) by aqueous nickel sulfide (NiS) under hydrothermal (>100 °C) conditions. A slurry of precipitated NiS converts acetylene and carbon monoxide into a set of C2–4-products that are surprisingly representative for C2–4-segments of all four central CO2-fixation cycles of the domains Bacteria and Archaea, whereby some of the products engage in the same interconversions, as seen in the central CO2-fixation cycles. The results suggest a primordial, chemically predetermined, non-cyclic acetyleno/carboxydotrophic core metabolism. This metabolism is based on aqueous organo–metal chemistry, from which the extant central CO2-fixation cycles based on thioester chemistry would have evolved by piecemeal modifications.
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136
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Djemiel C, Plassard D, Terrat S, Crouzet O, Sauze J, Mondy S, Nowak V, Wingate L, Ogée J, Maron PA. µgreen-db: a reference database for the 23S rRNA gene of eukaryotic plastids and cyanobacteria. Sci Rep 2020; 10:5915. [PMID: 32246067 PMCID: PMC7125122 DOI: 10.1038/s41598-020-62555-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 03/09/2020] [Indexed: 11/29/2022] Open
Abstract
Studying the ecology of photosynthetic microeukaryotes and prokaryotic cyanobacterial communities requires molecular tools to complement morphological observations. These tools rely on specific genetic markers and require the development of specialised databases to achieve taxonomic assignment. We set up a reference database, called µgreen-db, for the 23S rRNA gene. The sequences were retrieved from generalist (NCBI, SILVA) or Comparative RNA Web (CRW) databases, in addition to a more original approach involving recursive BLAST searches to obtain the best possible sequence recovery. At present, µgreen-db includes 2,326 23S rRNA sequences belonging to both eukaryotes and prokaryotes encompassing 442 unique genera and 736 species of photosynthetic microeukaryotes, cyanobacteria and non-vascular land plants based on the NCBI and AlgaeBase taxonomy. When PR2/SILVA taxonomy is used instead, µgreen-db contains 2,217 sequences (399 unique genera and 696 unique species). Using µgreen-db, we were able to assign 96% of the sequences of the V domain of the 23S rRNA gene obtained by metabarcoding after amplification from soil DNA at the genus level, highlighting good coverage of the database. µgreen-db is accessible at http://microgreen-23sdatabase.ea.inra.fr.
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Affiliation(s)
- Christophe Djemiel
- Agroécologie, AgroSup Dijon, INRA, University Bourgogne Franche-Comté, Dijon, France
| | | | - Sébastien Terrat
- Agroécologie, AgroSup Dijon, INRA, University Bourgogne Franche-Comté, Dijon, France
| | - Olivier Crouzet
- Univ. Paris Saclay, AgroParisTech, UMR ECOSYS, INRA, F-78206, Versailles, France
| | - Joana Sauze
- INRA, Bordeaux Science Agro, UMR 1391 ISPA, 33140, Villenave d'Ornon, France
| | - Samuel Mondy
- Agroécologie, AgroSup Dijon, INRA, University Bourgogne Franche-Comté, Dijon, France
| | - Virginie Nowak
- Agroécologie, AgroSup Dijon, INRA, University Bourgogne Franche-Comté, Dijon, France
| | - Lisa Wingate
- INRA, Bordeaux Science Agro, UMR 1391 ISPA, 33140, Villenave d'Ornon, France
| | - Jérôme Ogée
- INRA, Bordeaux Science Agro, UMR 1391 ISPA, 33140, Villenave d'Ornon, France
| | - Pierre-Alain Maron
- Agroécologie, AgroSup Dijon, INRA, University Bourgogne Franche-Comté, Dijon, France.
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137
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Liu L, Huber H, Berg IA. Enzymes Catalyzing Crotonyl-CoA Conversion to Acetoacetyl-CoA During the Autotrophic CO 2 Fixation in Metallosphaera sedula. Front Microbiol 2020; 11:354. [PMID: 32218776 PMCID: PMC7078158 DOI: 10.3389/fmicb.2020.00354] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 02/18/2020] [Indexed: 12/13/2022] Open
Abstract
Autotrophic Crenarchaeota use two different cycles for carbon dioxide fixation. Members of the Sulfolobales use the 3-hydroxypropionate/4-hydroxybutyrate (HP/HB) cycle, whereas Desulfurococcales and Thermoproteales use the dicarboxylate/4-hydroxybutyrate cycle. While these two cycles differ in the carboxylation reactions resulting in the conversion of acetyl-CoA + 2 CO2 to succinyl-CoA, they have a common regeneration part in which succinyl-CoA is reconverted to two acetyl-CoA molecules. This common part includes crotonyl-CoA conversion to acetoacetyl-CoA, which has unequivocally been shown in Ignicoccus hospitalis (Desulfurococcales) and Pyrobaculum neutrophilus (Thermoproteales) to be catalyzed by a bifunctional crotonase/3-hydroxybutyryl-CoA dehydrogenase. It is a fusion protein consisting of an enoyl-CoA hydratase and a dehydrogenase domain. As the homologous bifunctional protein is present in Sulfolobales as well, its common functioning in the conversion of crotonyl-CoA to acetoacetyl-CoA was proposed. Here we show that a model autotrophic member of Sulfolobales, Metallosphaera sedula, possesses in addition to the bifunctional protein (Msed_0399) several separate genes coding for crotonyl-CoA hydratase and (S)-3-hydroxybutyryl-CoA dehydrogenase. Their genes were previously shown to be transcribed under autotrophic and mixotrophic conditions. The dehydrogenase Msed_1423 (and not the bifunctional protein Msed_0399) appears to be the main enzyme catalyzing the (S)-3-hydroxybutyryl-CoA dehydrogenase reaction. Homologs of this dehydrogenase are the only (S)-3-hydroxybutyryl-CoA dehydrogenases present in all autotrophic Sulfolobales, strengthening this conclusion. Two uncharacterized crotonase homologs present in M. sedula genome (Msed_0336 and Msed_0384) were heterologously produced and characterized. Both proteins were highly efficient crotonyl-CoA hydratases and may contribute (or be responsible) for the corresponding reaction in the HP/HB cycle in vivo.
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Affiliation(s)
- Li Liu
- Institute for Molecular Microbiology and Biotechnology, University of Münster, Münster, Germany
| | - Harald Huber
- Institute for Microbiology and Archaeal Center, University of Regensburg, Regensburg, Germany
| | - Ivan A Berg
- Institute for Molecular Microbiology and Biotechnology, University of Münster, Münster, Germany
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138
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Dick GJ. The microbiomes of deep-sea hydrothermal vents: distributed globally, shaped locally. Nat Rev Microbiol 2020; 17:271-283. [PMID: 30867583 DOI: 10.1038/s41579-019-0160-2] [Citation(s) in RCA: 98] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The discovery of chemosynthetic ecosystems at deep-sea hydrothermal vents in 1977 changed our view of biology. Chemosynthetic bacteria and archaea form the foundation of vent ecosystems by exploiting the chemical disequilibrium between reducing hydrothermal fluids and oxidizing seawater, harnessing this energy to fix inorganic carbon into biomass. Recent research has uncovered fundamental aspects of these microbial communities, including their relationships with underlying geology and hydrothermal geochemistry, interactions with animals via symbiosis and distribution both locally in various habitats within vent fields and globally across hydrothermal systems in diverse settings. Although 'black smokers' and symbioses between microorganisms and macrofauna attract much attention owing to their novelty and the insights they provide into life under extreme conditions, habitats such as regions of diffuse flow, subseafloor aquifers and hydrothermal plumes have important roles in the global cycling of elements through hydrothermal systems. Owing to sharp contrasts in physical and chemical conditions between these various habitats and their dynamic, extreme and geographically isolated nature, hydrothermal vents provide a valuable window into the environmental and ecological forces that shape microbial communities and insights into the limits, origins and evolution of microbial life.
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Affiliation(s)
- Gregory J Dick
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA.
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139
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Zhao Y, Liu P, Rui J, Cheng L, Wang Q, Liu X, Yuan Q. Dark carbon fixation and chemolithotrophic microbial community in surface sediments of the cascade reservoirs, Southwest China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 698:134316. [PMID: 31783464 DOI: 10.1016/j.scitotenv.2019.134316] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/04/2019] [Accepted: 09/04/2019] [Indexed: 06/10/2023]
Abstract
Dark carbon fixation (DCF) by chemolithotrophic microbes can make considerable contribution to inorganic carbon fixation in aquatic ecosystems. However, little is known about the importance and diversity of chemolithotrophic microbes in cascade reservoir sediments. In this study, we determined the potential DCF rates of sediments of three cascade reservoirs in Wujiang River basin by carbon isotopic labeling. The results showed that the DCF rates of the surface sediments ranged from 1.5 to 14.7 mmol C m-2 d-1. The ratio of DCF to mineralization rate of sediment organic matter of surface sediment was between 11.6%~60.9%. High-throughput sequencing analysis of cbbL and cbbM genes involved in Calvin Benson Cycle indicated that cbbL-carrying CO2-assimilating bacteria included diverse functional groups, while cbbM type was mostly involved in sulfur oxidation. The sediments of Hongfeng (HF) reservoir, which has much longer hydraulic residence time (HRT) and locates in most upstream of a major tributary of Wujiang River, have substantially higher DCF rates. The cbbL and cbbM communities in HF were dominated by sulfur oxidizing bacteria, and were largely different from that in the other two reservoirs. Our results suggested that chemolithotrophy plays an important role in carbon cycling of sediments in cascade reservoir. Meanwhile, HRT and relative location of cascade reservoirs are the key control factors of both DCF and composition of autotrophic microbial communities in cascade reservoir sediments.
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Affiliation(s)
- Yuan Zhao
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Pengfei Liu
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, 35043 Marburg, Germany
| | - Junpeng Rui
- State Key Laboratory of Grassland Agro-Ecosystem, Institute of Innovation Ecology, Lanzhou University, Lanzhou 730000, China
| | - Lei Cheng
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture, Chengdu 610041, China
| | - Qian Wang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xing Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Quan Yuan
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
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140
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Son HF, Kim S, Seo H, Hong J, Lee D, Jin KS, Park S, Kim KJ. Structural insight into bi-functional malonyl-CoA reductase. Environ Microbiol 2019; 22:752-765. [PMID: 31814251 DOI: 10.1111/1462-2920.14885] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 11/23/2019] [Accepted: 12/04/2019] [Indexed: 11/27/2022]
Abstract
The bi-functional malonyl-CoA reductase is a key enzyme of the 3-hydroxypropionate bi-cycle for bacterial CO2 fixation, catalysing the reduction of malonyl-CoA to malonate semialdehyde and further reduction to 3-hydroxypropionate. Here, we report the crystal structure and the full-length architecture of malonyl-CoA reductase from Porphyrobacter dokdonensis. The malonyl-CoA reductase monomer of 1230 amino acids consists of four tandemly arranged short-chain dehydrogenases/reductases, with two catalytic and two non-catalytic short-chain dehydrogenases/reductases, and forms a homodimer through paring contact of two malonyl-CoA reductase monomers. The complex structures with its cofactors and substrates revealed that the malonyl-CoA substrate site is formed by the cooperation of two short-chain dehydrogenases/reductases and one novel extra domain, while only one catalytic short-chain dehydrogenase/reductase contributes to the formation of the malonic semialdehyde-binding site. The phylogenetic and structural analyses also suggest that the bacterial bi-functional malonyl-CoA has a structural origin that is completely different from the archaeal mono-functional malonyl-CoA and malonic semialdehyde reductase, and thereby constitute an efficient enzyme.
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Affiliation(s)
- Hyeoncheol Francis Son
- School of Life Sciences (KNU Creative BioResearch Group), KNU Institute for Microorganisms, Kyungpook National University, Daegu, South Korea
| | - Sangwoo Kim
- School of Life Sciences (KNU Creative BioResearch Group), KNU Institute for Microorganisms, Kyungpook National University, Daegu, South Korea
| | - Hogyun Seo
- School of Life Sciences (KNU Creative BioResearch Group), KNU Institute for Microorganisms, Kyungpook National University, Daegu, South Korea
| | - Jiyeon Hong
- School of Life Sciences (KNU Creative BioResearch Group), KNU Institute for Microorganisms, Kyungpook National University, Daegu, South Korea
| | - Donghoon Lee
- School of Life Sciences (KNU Creative BioResearch Group), KNU Institute for Microorganisms, Kyungpook National University, Daegu, South Korea
| | - Kyeong Sik Jin
- Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang, South Korea
| | - Sunghoon Park
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, South Korea
| | - Kyung-Jin Kim
- School of Life Sciences (KNU Creative BioResearch Group), KNU Institute for Microorganisms, Kyungpook National University, Daegu, South Korea
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141
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Lezcano MÁ, Moreno-Paz M, Carrizo D, Prieto-Ballesteros O, Fernández-Martínez MÁ, Sánchez-García L, Blanco Y, Puente-Sánchez F, de Diego-Castilla G, García-Villadangos M, Fairén AG, Parro V. Biomarker Profiling of Microbial Mats in the Geothermal Band of Cerro Caliente, Deception Island (Antarctica): Life at the Edge of Heat and Cold. ASTROBIOLOGY 2019; 19:1490-1504. [PMID: 31339746 PMCID: PMC6918857 DOI: 10.1089/ast.2018.2004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 06/15/2019] [Indexed: 05/04/2023]
Abstract
Substrate-atmosphere interfaces in Antarctic geothermal environments are hot-cold regions that constitute thin habitable niches for microorganisms with possible counterparts in ancient Mars. Cerro Caliente hill in Deception Island (active volcano in the South Shetland Islands) is affected by ascending hydrothermal fluids that form a band of warm substrates buffered by low air temperatures. We investigated the influence of temperature on the community structure and metabolism of three microbial mats collected along the geothermal band of Cerro Caliente registering 88°C, 8°C, and 2°C at the time of collection. High-throughput sequencing of small subunit ribosomal ribonucleic acid (SSU rRNA) genes and Life Detector Chip (LDChip) microarray immunoassays revealed different bacterial, archaeal, and eukaryotic composition in the three mats. The mat at 88°C showed the less diverse microbial community and a higher proportion of thermophiles (e.g., Thermales). In contrast, microbial communities in the mats at 2°C and 8°C showed relatively higher diversity and higher proportion of psychrophiles (e.g., Flavobacteriales). Despite this overall association, similar microbial structures at the phylum level (particularly the presence of Cyanobacteria) and certain hot- and cold-tolerant microorganisms were identified in the three mats. Daily thermal oscillations recorded in the substrate over the year (4.5-76°C) may explain the coexistence of microbial fingerprints with different thermal tolerances. Stable isotope composition also revealed metabolic differences among the microbial mats. Carbon isotopic ratios suggested the Calvin-Benson-Bassham cycle as the major pathway for carbon dioxide fixation in the mats at 2°C and 8°C, and the reductive tricarboxylic acid cycle and/or the 3-hydroxypropionate bicycle for the mat at 88°C, indicating different metabolisms as a function of the prevailing temperature of each mat. The comprehensive biomarker profile on the three microbial mats from Cerro Caliente contributes to unravel the diversity, composition, and metabolism in geothermal polar sites and highlights the relevance of geothermal-cold environments to create habitable niches with interest in other planetary environments.
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Affiliation(s)
- María Ángeles Lezcano
- Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), Madrid, Spain
| | - Mercedes Moreno-Paz
- Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), Madrid, Spain
| | - Daniel Carrizo
- Department of Planetology and Habitability, Centro de Astrobiología (CSIC-INTA), Madrid, Spain
| | - Olga Prieto-Ballesteros
- Department of Planetology and Habitability, Centro de Astrobiología (CSIC-INTA), Madrid, Spain
| | | | - Laura Sánchez-García
- Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), Madrid, Spain
| | - Yolanda Blanco
- Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), Madrid, Spain
| | | | | | | | - Alberto G. Fairén
- Department of Planetology and Habitability, Centro de Astrobiología (CSIC-INTA), Madrid, Spain
- Department of Astronomy, Cornell University, Ithaca, New York, USA
| | - Víctor Parro
- Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), Madrid, Spain
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142
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Yang Z, Zhang Y, Lv Y, Yan W, Xiao X, Sun B, Ma H. H 2 Metabolism revealed by metagenomic analysis of subglacial sediment from East Antarctica. J Microbiol 2019; 57:1095-1104. [PMID: 31758395 DOI: 10.1007/s12275-019-9366-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 10/14/2019] [Accepted: 11/06/2019] [Indexed: 01/17/2023]
Abstract
Subglacial ecosystems harbor diverse chemoautotrophic microbial communities in areas with limited organic carbon, and lithological H2 produced during glacial erosion has been considered an important energy source in these ecosystems. To verify the H2-utilizing potential there and to identify the related energy-converting metabolic mechanisms of these communities, we performed metagenomic analysis on subglacial sediment samples from East Antarctica with and without H2 supplementation. Genes coding for several [NiFe]-hydrogenases were identified in raw sediment and were enriched after H2 incubation. All genes in the dissimilatory nitrate reduction and denitrification pathways were detected in the subglacial community, and the genes coding for these pathways became enriched after H2 was supplied. Similarly, genes transcribing key enzymes in the Calvin cycle were detected in raw sediment and were also enriched. Moreover, key genes involved in H2 oxidization, nitrate reduction, oxidative phosphorylation, and the Calvin cycle were identified within one metagenome-assembled genome belonging to a Polaromonas sp. As suggested by our results, the microbial community in the subglacial environment we investigated consisted of chemoautotrophic populations supported by H2 oxidation. These results further confirm the importance of H2 in the cryosphere.
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Affiliation(s)
- Zhifeng Yang
- SOA Key Laboratory for Polar Science, Polar Research Institute of China, Shanghai, P. R. China.,State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai, P. R. China.,School of Oceanography, Shanghai Jiao Tong University, Shanghai, P. R. China
| | - Yu Zhang
- State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai, P. R. China.,School of Oceanography, Shanghai Jiao Tong University, Shanghai, P. R. China
| | - Yongxin Lv
- State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai, P. R. China.,School of Oceanography, Shanghai Jiao Tong University, Shanghai, P. R. China
| | - Wenkai Yan
- State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai, P. R. China.,School of Oceanography, Shanghai Jiao Tong University, Shanghai, P. R. China
| | - Xiang Xiao
- State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai, P. R. China.,School of Oceanography, Shanghai Jiao Tong University, Shanghai, P. R. China
| | - Bo Sun
- SOA Key Laboratory for Polar Science, Polar Research Institute of China, Shanghai, P. R. China
| | - Hongmei Ma
- SOA Key Laboratory for Polar Science, Polar Research Institute of China, Shanghai, P. R. China.
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143
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Kato S, Hirai M, Ohkuma M, Suzuki K. Microbial metabolisms in an abyssal ferromanganese crust from the Takuyo-Daigo Seamount as revealed by metagenomics. PLoS One 2019; 14:e0224888. [PMID: 31703093 PMCID: PMC6839870 DOI: 10.1371/journal.pone.0224888] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 10/23/2019] [Indexed: 11/18/2022] Open
Abstract
Rocky outcrops covered with thick Fe and Mn oxide coatings, which are known as ferromanganese (Fe-Mn) crusts, are commonly found on slopes of aged seamounts in bathyal and abyssal zones. Although the presence of diverse microorganisms on these Fe-Mn crusts has been reported, little is known about their metabolism. Here, we report the metabolic potential of the microbial community in an abyssal crust collected in the Takuyo-Daigo Seamount, in the north-western Pacific. We performed shotgun metagenomic sequencing of the Fe-Mn crust, and detected putative genes involved in dissolution and precipitation of Fe and Mn, nitrification, sulfur oxidation, carbon fixation, and decomposition of organics in the metagenome. In addition, four metagenome-assembled genomes (MAGs) of abundant members in the microbial community were recovered from the metagenome. The MAGs were affiliated with Thaumarchaeota, Alphaproteobacteria, and Gammaproteobacteria, and were distantly related to previously reported genomes/MAGs of cultured and uncultured species. Putative genes involved in the above reactions were also found in the crust MAGs. Our results suggest that crust microbial communities play a role in biogeochemical cycling of C, N, S, Fe, and Mn, and imply that they contribute to the growth of Fe-Mn crusts.
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Affiliation(s)
- Shingo Kato
- Submarine Resources Research Center, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, Japan
- Japan Collection of Microorganisms (JCM), RIKEN BioResource Research Center, Tsukuba, Ibaraki, Japan
| | - Miho Hirai
- Research and Development Center for Marine Biosciences, JAMSTEC, Yokosuka, Kanagawa, Japan
| | - Moriya Ohkuma
- Japan Collection of Microorganisms (JCM), RIKEN BioResource Research Center, Tsukuba, Ibaraki, Japan
| | - Katsuhiko Suzuki
- Submarine Resources Research Center, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, Japan
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144
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Trophic structure of the macrofauna associated to deep-vents of the southern Gulf of California: Pescadero Basin and Pescadero Transform Fault. PLoS One 2019; 14:e0224698. [PMID: 31689305 PMCID: PMC6830743 DOI: 10.1371/journal.pone.0224698] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 10/18/2019] [Indexed: 11/19/2022] Open
Abstract
Newly discovered hydrothermal systems in the Pescadero Basin (PB) and the neighboring Pescadero Transform Fault (PTF) at the mouth of the Gulf of California disclosed a diverse macrofauna assemblage. The trophic structure of both ecosystems was assessed using carbon (δ13C), nitrogen (δ15N), and sulfur (δ34S) stable isotopes. The δ13C ranged from -40.8 to -12.1‰, revealing diverse carbon sources and its assimilation via Calvin-Benson-Bassham and the reductive tricarboxylic acid cycles. The δ15N values were between -12.5 and 18.3‰, corresponding to primary and secondary consumers. The δ34S values fluctuated from -36.2 to 15.1‰, indicating the sulfide assimilation of biogenic, magmatic, and photosynthetic sources. In PB high-temperature vents, primary consumers including symbiont-bearing, bacterivores and filter-feeders predominated. The secondary consumers within the scavengers/detritivores and predator guilds were scarce. The siboglinid Oasisia aff alvinae dominated the macrofauna assemblage at PB, but rather than playing a trophic role, it provides a substrate to vent dwellers. In PTF low-temperature vents, only symbiont-bearing primary consumers were analyzed, displaying the lowest δ34S values. This assemblage was dominated by the coexisting siboglinids Lamellibrachia barhami and Escarpia spicata. δ34S values allowed to distinguish between PB and PTF vent communities, to exclude the presence of methanotrophic organisms, and the detection of photosynthetic organic matter input.
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145
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Linse K, Copley JT, Connelly DP, Larter RD, Pearce DA, Polunin NVC, Rogers AD, Chen C, Clarke A, Glover AG, Graham AGC, Huvenne VAI, Marsh L, Reid WDK, Roterman CN, Sweeting CJ, Zwirglmaier K, Tyler PA. Fauna of the Kemp Caldera and its upper bathyal hydrothermal vents (South Sandwich Arc, Antarctica). ROYAL SOCIETY OPEN SCIENCE 2019; 6:191501. [PMID: 31827872 PMCID: PMC6894572 DOI: 10.1098/rsos.191501] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 10/23/2019] [Indexed: 05/24/2023]
Abstract
Faunal assemblages at hydrothermal vents associated with island-arc volcanism are less well known than those at vents on mid-ocean ridges and back-arc spreading centres. This study characterizes chemosynthetic biotopes at active hydrothermal vents discovered at the Kemp Caldera in the South Sandwich Arc. The caldera hosts sulfur and anhydrite vent chimneys in 1375-1487 m depth, which emit sulfide-rich fluids with temperatures up to 212°C, and the microbial community of water samples in the buoyant plume rising from the vents was dominated by sulfur-oxidizing Gammaproteobacteria. A total of 12 macro- and megafaunal taxa depending on hydrothermal activity were collected in these biotopes, of which seven species were known from the East Scotia Ridge (ESR) vents and three species from vents outside the Southern Ocean. Faunal assemblages were dominated by large vesicomyid clams, actinostolid anemones, Sericosura sea spiders and lepetodrilid and cocculinid limpets, but several taxa abundant at nearby ESR hydrothermal vents were rare such as the stalked barnacle Neolepas scotiaensis. Multivariate analysis of fauna at Kemp Caldera and vents in neighbouring areas indicated that the Kemp Caldera is most similar to vent fields in the previously established Southern Ocean vent biogeographic province, showing that the species composition at island-arc hydrothermal vents can be distinct from nearby seafloor-spreading systems. δ 13C and δ 15N isotope values of megafaunal species analysed from the Kemp Caldera were similar to those of the same or related species at other vent fields, but none of the fauna sampled at Kemp Caldera had δ 13C values, indicating nutritional dependence on Epsilonproteobacteria, unlike fauna at other island-arc hydrothermal vents.
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Affiliation(s)
- Katrin Linse
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Jonathan T. Copley
- Ocean and Earth Science, University of Southampton, Waterfront Campus, Southampton SO14 3ZH, UK
| | | | - Robert D. Larter
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - David A. Pearce
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Nick V. C. Polunin
- School of Natural and Environmental Sciences, Newcastle University, Ridley Building, Newcastle upon Tyne NE1 7RU, UK
| | - Alex D. Rogers
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
| | - Chong Chen
- X-STAR, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Kanagawa Pref. Japan
| | - Andrew Clarke
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Adrian G. Glover
- Life Sciences Department, Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | | | | | - Leigh Marsh
- Ocean and Earth Science, University of Southampton, Waterfront Campus, Southampton SO14 3ZH, UK
| | - William D. K. Reid
- School of Natural and Environmental Sciences, Newcastle University, Ridley Building, Newcastle upon Tyne NE1 7RU, UK
| | - C. Nicolai Roterman
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
| | - Christopher J. Sweeting
- School of Natural and Environmental Sciences, Newcastle University, Ridley Building, Newcastle upon Tyne NE1 7RU, UK
| | - Katrin Zwirglmaier
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Paul A. Tyler
- Ocean and Earth Science, University of Southampton, Waterfront Campus, Southampton SO14 3ZH, UK
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146
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Alfreider A, Tartarotti B. Spatiotemporal dynamics of different CO 2 fixation strategies used by prokaryotes in a dimictic lake. Sci Rep 2019; 9:15068. [PMID: 31636358 PMCID: PMC6803681 DOI: 10.1038/s41598-019-51584-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 09/30/2019] [Indexed: 01/18/2023] Open
Abstract
The Calvin-Benson-Bassham (CBB) cycle and the 3-hydroxypropionate/4-hydroxybutyrate (HP/HB) cycle are two inorganic carbon assimilation pathways widely used by prokaryotic autotrophs in lakes. We investigated the effect of mixing periods and stable water stratification patterns on the trajectories of both CO2 fixation strategies in a dimictic lake (Piburger See), because information on the spatiotemporal dynamics of prokaryotes using these pathways in freshwater ecosystems is far from complete. Based on a quantitative approach (droplet digital PCR) of genes coding for key enzymes in different CO2 assimilation pathways, nine depths covering the entire water column were investigated on a monthly basis for one year. Our data show that the abundance of photoautotrophs and obligate chemolithoautotrophs preferentially using form IA RubisCO was determined by seasonal variations. Highest numbers were observed in summer, while a strong decline of prokrayotes using RubisCO form IA was measured between December and May, the period where the lake was mostly covered by ice. The spatiotemporal distribution patterns of genes coding for RubisCO form IC genes, an enzyme usually used by facultative autotrophs for CO2 assimilation, were less pronounced. Bacteria harboring RubisCO form II were dominating the oxygen limited hypolimnion, while nitrifying Thaumarchaeota using the HP/HB cycle were of minor importance in the lake. Our data reveal that the seasonal heterogeneity, which is determined by the dimictic thermal regime of the lake, results in pronounced spatiotemporal changes of different CO2 assimilation pathways with depth-dependent environmental parameters as key factors for their distribution.
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Affiliation(s)
- Albin Alfreider
- Department of Ecology, University of Innsbruck, Innsbruck, Austria.
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147
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Böhnke S, Sass K, Gonnella G, Diehl A, Kleint C, Bach W, Zitoun R, Koschinsky A, Indenbirken D, Sander SG, Kurtz S, Perner M. Parameters Governing the Community Structure and Element Turnover in Kermadec Volcanic Ash and Hydrothermal Fluids as Monitored by Inorganic Electron Donor Consumption, Autotrophic CO 2 Fixation and 16S Tags of the Transcriptome in Incubation Experiments. Front Microbiol 2019; 10:2296. [PMID: 31649639 PMCID: PMC6794353 DOI: 10.3389/fmicb.2019.02296] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 09/20/2019] [Indexed: 12/01/2022] Open
Abstract
The microbial community composition and its functionality was assessed for hydrothermal fluids and volcanic ash sediments from Haungaroa and hydrothermal fluids from the Brothers volcano in the Kermadec island arc (New Zealand). The Haungaroa volcanic ash sediments were dominated by epsilonproteobacterial Sulfurovum sp. Ratios of electron donor consumption to CO2 fixation from respective sediment incubations indicated that sulfide oxidation appeared to fuel autotrophic CO2 fixation, coinciding with thermodynamic estimates predicting sulfide oxidation as the major energy source in the environment. Transcript analyses with the sulfide-supplemented sediment slurries demonstrated that Sulfurovum prevailed in the experiments as well. Hence, our sediment incubations appeared to simulate environmental conditions well suggesting that sulfide oxidation catalyzed by Sulfurovum members drive biomass synthesis in the volcanic ash sediments. For the Haungaroa fluids no inorganic electron donor and responsible microorganisms could be identified that clearly stimulated autotrophic CO2 fixation. In the Brothers hydrothermal fluids Sulfurimonas (49%) and Hydrogenovibrio/Thiomicrospira (15%) species prevailed. Respective fluid incubations exhibited highest autotrophic CO2 fixation if supplemented with iron(II) or hydrogen. Likewise catabolic energy calculations predicted primarily iron(II) but also hydrogen oxidation as major energy sources in the natural fluids. According to transcript analyses with material from the incubation experiments Thiomicrospira/Hydrogenovibrio species dominated, outcompeting Sulfurimonas. Given that experimental conditions likely only simulated environmental conditions that cause Thiomicrospira/Hydrogenovibrio but not Sulfurimonas to thrive, it remains unclear which environmental parameters determine Sulfurimonas’ dominance in the Brothers natural hydrothermal fluids.
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Affiliation(s)
- Stefanie Böhnke
- Molecular Biology of Microbial Consortia, Institute of Plant Science and Microbiology, Universität Hamburg, Hamburg, Germany
| | - Katharina Sass
- Molecular Biology of Microbial Consortia, Institute of Plant Science and Microbiology, Universität Hamburg, Hamburg, Germany
| | - Giorgio Gonnella
- Center for Bioinformatics (ZBH), Universität Hamburg, Hamburg, Germany
| | - Alexander Diehl
- Department of Geosciences, MARUM - Centre for Marine Environmental Sciences, University of Bremen, Bremen, Germany
| | - Charlotte Kleint
- Department of Physics and Earth Sciences, Jacobs University Bremen, Bremen, Germany
| | - Wolfgang Bach
- Department of Geosciences, MARUM - Centre for Marine Environmental Sciences, University of Bremen, Bremen, Germany
| | - Rebecca Zitoun
- Department of Chemistry, University of Otago, Dunedin, New Zealand
| | - Andrea Koschinsky
- Department of Physics and Earth Sciences, Jacobs University Bremen, Bremen, Germany
| | - Daniela Indenbirken
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Sylvia G Sander
- Department of Chemistry, University of Otago, Dunedin, New Zealand
| | - Stefan Kurtz
- Center for Bioinformatics (ZBH), Universität Hamburg, Hamburg, Germany
| | - Mirjam Perner
- Molecular Biology of Microbial Consortia, Institute of Plant Science and Microbiology, Universität Hamburg, Hamburg, Germany
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148
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Effect of Hydraulic Retention Time on Carbon Sequestration during the Two-Stage Anammox Process. Processes (Basel) 2019. [DOI: 10.3390/pr7100717] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In a biological treatment process, hydraulic retention time (HRT) has a certain effect on the operation of the reactor. This study investigated the effect of HRT on carbon sequestration in a two-stage anaerobic ammonium oxidation (anammox) process using a partial nitrification reactor and anammox reactor to determine the optimal carbon sequestration operating conditions. Molecular biotechnology was used to analyze the sludge in the reactor in order to explore the denitrification performance and to determine the carbon sequestration pathway of the microorganisms. The results show that the partial nitrification stage had the highest carbon sequestration rate (0.319 mg/mg·N) when the nitrogen loading rate (NLR) was 0.44 kg·N/m3/d. The NLR of the anammox stage was 0.13 kg·N/m3/d. When the HRT was 33.4 h, the carbon sequestration of the anammox reaction was at its highest, reaching 0.183 mg/mg·N. The results of microbial analysis show that the carbon-fixing gene cbbLR1 was present in the sludge samples during the anammox and partial nitrification stages, and that there was a Calvin cycle carbon sequestration pathway during the growth process. However, the existence of a gene for reducing and immobilizing CO2 by the acetyl-CoA pathway was not detected; further research is thus needed.
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149
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Chi XQ, Wang L, Guo R, Zhao D, Li J, Zhang Y, Jiao N. RuBisCO large subunit gene primers for assessing the CO2-assimilating planktonic community structure in Jiaozhou Bay, China. FEMS Microbiol Lett 2019; 365:5040227. [PMID: 29931181 DOI: 10.1093/femsle/fny140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 06/02/2018] [Indexed: 11/13/2022] Open
Abstract
The protein coding genes (rbcL/cbbL/cbbM) for RuBisCO large subunit, the most abundant protein on earth that drives biological CO2 fixation, were considered as useful marker genes in characterizing CO2-assimilating plankton. However, their community specificity has hindered comprehensive screening of genetic diversity. In this study, six different rbcL/cbbL/cbbM primers were employed to screen clone libraries to identify CO2-assimilating plankton in Jiaozhou Bay. The following community compositions were observed: the community components in Form I A/B rbcL/cbbL clone library mainly comprised Chlorophyta and Proteobacteria, Form ID2 and ID3 libraries consisted of Bacillariophyta, Form II cbbM library consisted of Proteobacteria and Alveolata, and both Form I green and red libraries included Proteobacteria, respectively. At the genus taxonomic level, no overlaps among these clone libraries were observed, except for ID2 and ID3. Overall, the phytoplankton in Jiaozhou Bay mainly consists of Bacillariophyta, Chlorophyta, Cryptophyta, Haptophyceae and Alveolata. The CO2-assimilating prokaryotes mainly consist of Proteobacteria. Considering the high-sequence specificities of these marker genes, we propose that the joint use of multiple primers may be utilized in unveiling the diversity of CO2-assimilating organisms. In addition, designing novel RuBisCO gene primers that generate longer amplicons and have broader phylogenetic coverage may be necessary in the future.
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Affiliation(s)
- Xiang-Qun Chi
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Songling Road, Qingdao 266101, Shandong, China.,BGI-Qingdao, Qingdao 266555, China
| | - Long Wang
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Songling Road, Qingdao 266101, Shandong, China
| | - Ruoyu Guo
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Songling Road, Qingdao 266101, Shandong, China
| | - Dexi Zhao
- Tianjin Branch of China National Offshore Oil Corporation Ltd. Tianjin 300450, China
| | - Jia Li
- Tianjin Branch of China National Offshore Oil Corporation Ltd. Tianjin 300450, China
| | - Yongyu Zhang
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Songling Road, Qingdao 266101, Shandong, China
| | - Nianzhi Jiao
- Institute of Marine Microbes and Ecospheres, State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361101, China
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Koziaeva V, Dziuba M, Leão P, Uzun M, Krutkina M, Grouzdev D. Genome-Based Metabolic Reconstruction of a Novel Uncultivated Freshwater Magnetotactic coccus " Ca. Magnetaquicoccus inordinatus" UR-1, and Proposal of a Candidate Family " Ca. Magnetaquicoccaceae". Front Microbiol 2019; 10:2290. [PMID: 31632385 PMCID: PMC6783814 DOI: 10.3389/fmicb.2019.02290] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 09/19/2019] [Indexed: 12/20/2022] Open
Abstract
Magnetotactic bacteria are widely represented microorganisms that have the ability to synthesize magnetosomes. The magnetotactic cocci of the order Magnetococcales are the most frequently identified, but their classification remains unclear due to the low number of cultivated representatives. This paper reports the analysis of an uncultivated magnetotactic coccus UR-1 collected from the Uda River (in eastern Siberia). Genome analyses of this bacterium and comparison to the available Magnetococcales genomes identified a novel species called "Ca. Magnetaquicoccus inordinatus," and a delineated candidate family "Ca. Magnetaquicoccaceae" within the order Magnetococcales is proposed. We used average amino acid identity values <55-56% and <64-65% as thresholds for the separation of families and genera, respectively, within the order Magnetococcales. Analyses of the genome sequence of UR-1 revealed a potential ability for a chemolithoautotrophic lifestyle, with the oxidation of a reduced sulfur compound and carbon assimilation by rTCA. A nearly complete magnetosome genome island, containing a set of mam and mms genes, was also identified. Further comparative analyses of the magnetosome genes showed vertical inheritance as well as horizontal gene transfer as the evolutionary drivers of magnetosome biomineralization genes in strains of the order Magnetococcales.
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Affiliation(s)
- Veronika Koziaeva
- Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, Moscow, Russia
| | - Marina Dziuba
- Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, Moscow, Russia
- Department of Microbiology, University of Bayreuth, Bayreuth, Germany
| | - Pedro Leão
- Instituto de Microbiologia Paulo de Góes, Universidade Federal Do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Maria Uzun
- Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, Moscow, Russia
- Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Maria Krutkina
- Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, Moscow, Russia
| | - Denis Grouzdev
- Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, Moscow, Russia
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