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Koziaeva VV, Sorokin DY, Kolganova TV, Grouzdev DS. Magnetospirillum sulfuroxidans sp. nov., capable of sulfur-dependent lithoautotrophy and a taxonomic reevaluation of the order Rhodospirillales. Syst Appl Microbiol 2023; 46:126406. [PMID: 36898262 DOI: 10.1016/j.syapm.2023.126406] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 02/12/2023] [Accepted: 02/22/2023] [Indexed: 02/27/2023]
Abstract
A spiral-shaped, highly motile bacterium was isolated from freshwater sulfidic sediment. Strain J10T is a facultative autotroph utilizing sulfide, thiosulfate, and sulfur as the electron donors in microoxic conditions. Despite high 16S rRNA gene sequence sequence identity to Magnetospirillum gryphiswaldense MSR-1 T (99.6 %), digital DNA-DNA hybridisation homology and average nucleotide identity between the two strains was of the different species level (25 % and 83 %, respectively). Strain J10T is not magnetotactic. The DNA G + C content of strain J10T is 61.9 %. The predominant phospholipid ester-linked fatty acids are C18:1ω7, C16:1ω7, and C16:0. Strain J10T (=DSM 23205 T = VKM B-3486 T) is the first strain of the genus Magnetospirillum showing lithoautotrophic growth and is proposed here as a novel species, Magnetospirillum sulfuroxidans sp. nov. In addition, we propose to establish a framework for distinguishing genera and families within the order Rhodospirillales based on phylogenomic analysis using the threshold values for average amino acid identity at ̴ 72 % for genera and ̴ 60 % for families. According to this, we propose to divide the existing genus Magnetospirillum into three genera: Magnetospirillum, Paramagnetospirillum, and Phaeospirillum, constituting a separate family Magnetospirillaceae fam. nov. in the order Rhodospirillales. Furthermore, phylogenomic data suggest that this order should accomodate six more new family level groups including Magnetospiraceae fam. nov., Magnetovibrionaceae fam. nov., Dongiaceae fam. nov., Niveispirillaceae fam. nov., Fodinicurvataceae fam. nov., and Oceanibaculaceae fam. nov.
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Affiliation(s)
- Veronika V Koziaeva
- Skryabin Institute of Bioengineering, Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, Russia.
| | - Dimitry Y Sorokin
- Winogradsky Institute of Microbiology, Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, Russia; Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Tatiana V Kolganova
- Skryabin Institute of Bioengineering, Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, Russia
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Abstract
Wetlands are the major natural source of methane, an important greenhouse gas. The sulfur and methane cycles in wetlands are linked—e.g., a strong sulfur cycle can inhibit methanogenesis. Although there has historically been a clear distinction drawn between methane and sulfur oxidizers, here, we isolated a methanotroph that also performed respiratory oxidization of sulfur compounds. We experimentally demonstrated that thiotrophy and methanotrophy are metabolically compatible, and both metabolisms could be expressed simultaneously in a single microorganism. These findings suggest that mixotrophic methane/sulfur-oxidizing bacteria are a previously overlooked component of environmental methane and sulfur cycles. This creates a framework for a better understanding of these redox cycles in natural and engineered wetlands. Natural and anthropogenic wetlands are major sources of the atmospheric greenhouse gas methane. Methane emissions from wetlands are mitigated by methanotrophic bacteria at the oxic–anoxic interface, a zone of intense redox cycling of carbon, sulfur, and nitrogen compounds. Here, we report on the isolation of an aerobic methanotrophic bacterium, ‘Methylovirgula thiovorans' strain HY1, which possesses metabolic capabilities never before found in any methanotroph. Most notably, strain HY1 is the first bacterium shown to aerobically oxidize both methane and reduced sulfur compounds for growth. Genomic and proteomic analyses showed that soluble methane monooxygenase and XoxF-type alcohol dehydrogenases are responsible for methane and methanol oxidation, respectively. Various pathways for respiratory sulfur oxidation were present, including the Sox–rDsr pathway and the S4I system. Strain HY1 employed the Calvin–Benson–Bassham cycle for CO2 fixation during chemolithoautotrophic growth on reduced sulfur compounds. Proteomic and microrespirometry analyses showed that the metabolic pathways for methane and thiosulfate oxidation were induced in the presence of the respective substrates. Methane and thiosulfate could therefore be independently or simultaneously oxidized. The discovery of this versatile bacterium demonstrates that methanotrophy and thiotrophy are compatible in a single microorganism and underpins the intimate interactions of methane and sulfur cycles in oxic–anoxic interface environments.
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Pang Y, Hu L, Wang J. Mixotrophic denitrification using pyrite and biodegradable polymer composite as electron donors. BIORESOURCE TECHNOLOGY 2022; 351:127011. [PMID: 35307522 DOI: 10.1016/j.biortech.2022.127011] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/10/2022] [Accepted: 03/12/2022] [Indexed: 06/14/2023]
Abstract
The denitrification performance of a novel mixotrophic system using pyrite (FeS2) and biodegradable polymer composite (PLA/PHBV/rice hulls, PPRH) as electron donors was investigated. After 12-day operation, the average nitrate removal rate (16.3-40.6 mg-N/L/d) in the mixotrophic system was 37% higher than the combined rate in the single heterotrophic and autotrophic system. The XPS analysis identified the formation of SO42-, S2- and Fe(Ш) on the pyrite surface during mixotrophic operation. The predicted microbial function analysis by PICRUSt2 revealed that the genes involved in S-oxidation, denitrification and carbon fixation were notably enriched in the mixotrophic system, indicating the increasing contribution of autotrophic S-oxidizing denitrification to total nitrate removal. Moreover, network analysis suggested the synergistic interactions among heterotrophic denitrifiers, S-oxidizing denitrifiers, sulfate reducers, Fe(II)-oxidizing denitrifiers and Fe(Ш) reducers. This study provides novel insights into the molecular mechanism of C, N, S and Fe cycle in the pyrite/PPRH based mixotrophic denitrification system.
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Affiliation(s)
- Yunmeng Pang
- Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084, PR China; Beijing Key Laboratory of Radioactive Waste Treatment, INET, Tsinghua University, Beijing 100084, PR China
| | - Liang Hu
- School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, PR China
| | - Jianlong Wang
- Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084, PR China; Beijing Key Laboratory of Radioactive Waste Treatment, INET, Tsinghua University, Beijing 100084, PR China.
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Monteil CL, Grouzdev DS, Perrière G, Alonso B, Rouy Z, Cruveiller S, Ginet N, Pignol D, Lefevre CT. Repeated horizontal gene transfers triggered parallel evolution of magnetotaxis in two evolutionary divergent lineages of magnetotactic bacteria. THE ISME JOURNAL 2020; 14:1783-1794. [PMID: 32296121 PMCID: PMC7305187 DOI: 10.1038/s41396-020-0647-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 03/21/2020] [Accepted: 03/24/2020] [Indexed: 12/27/2022]
Abstract
Under the same selection pressures, two genetically divergent populations may evolve in parallel toward the same adaptive solutions. Here, we hypothesized that magnetotaxis (i.e., magnetically guided chemotaxis) represents a key adaptation to micro-oxic habitats in aquatic sediments and that its parallel evolution homogenized the phenotypes of two evolutionary divergent clusters of freshwater spirilla. All magnetotactic bacteria affiliated to the Magnetospirillum genus (Alphaproteobacteria class) biomineralize the same magnetic particle chains and share highly similar physiological and ultrastructural features. We looked for the processes that could have contributed at shaping such an evolutionary pattern by reconciling species and gene trees using newly sequenced genomes of Magnetospirillum related bacteria. We showed that repeated horizontal gene transfers and homologous recombination of entire operons contributed to the parallel evolution of magnetotaxis. We propose that such processes could represent a more parsimonious and rapid solution for adaptation compared with independent and repeated de novo mutations, especially in the case of traits as complex as magnetotaxis involving tens of interacting proteins. Besides strengthening the idea about the importance of such a function in micro-oxic habitats, these results reinforce previous observations in experimental evolution suggesting that gene flow could alleviate clonal interference and speed up adaptation under some circumstances.
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Affiliation(s)
- Caroline L Monteil
- Aix-Marseille University, CEA, CNRS, Biosciences and Biotechnologies Institute of Aix-Marseille, Saint Paul lez Durance, France.
| | - Denis S Grouzdev
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | - Guy Perrière
- Laboratoire de Biométrie et Biologie Evolutive, CNRS, UMR5558, Université Claude Bernard - Lyon 1, 69622, Villeurbanne, France
| | - Béatrice Alonso
- Aix-Marseille University, CEA, CNRS, Biosciences and Biotechnologies Institute of Aix-Marseille, Saint Paul lez Durance, France
| | - Zoé Rouy
- LABGeM, Genomique Metabolique, CEA, Genoscope, Institut Francois Jacob, CNRS, Universite d'Evry, Universite Paris-Saclay, Evry, France
| | - Stéphane Cruveiller
- LABGeM, Genomique Metabolique, CEA, Genoscope, Institut Francois Jacob, CNRS, Universite d'Evry, Universite Paris-Saclay, Evry, France
| | - Nicolas Ginet
- Aix Marseille University, CNRS, LCB, Marseille, France
| | - David Pignol
- Aix-Marseille University, CEA, CNRS, Biosciences and Biotechnologies Institute of Aix-Marseille, Saint Paul lez Durance, France
| | - Christopher T Lefevre
- Aix-Marseille University, CEA, CNRS, Biosciences and Biotechnologies Institute of Aix-Marseille, Saint Paul lez Durance, France.
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Amor M, Mathon FP, Monteil CL, Busigny V, Lefevre CT. Iron-biomineralizing organelle in magnetotactic bacteria: function, synthesis and preservation in ancient rock samples. Environ Microbiol 2020; 22:3611-3632. [PMID: 32452098 DOI: 10.1111/1462-2920.15098] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/21/2020] [Accepted: 05/23/2020] [Indexed: 12/22/2022]
Abstract
Magnetotactic bacteria (MTB) are ubiquitous aquatic microorganisms that incorporate iron from their environment to synthesize intracellular nanoparticles of magnetite (Fe3 O4 ) or greigite (Fe3 S4 ) in a genetically controlled manner. Magnetite and greigite magnetic phases allow MTB to swim towards redox transition zones where they thrive. MTB may represent some of the oldest microorganisms capable of synthesizing minerals on Earth and have been proposed to significantly impact the iron biogeochemical cycle by immobilizing soluble iron into crystals that subsequently fossilize in sedimentary rocks. In the present article, we describe the distribution of MTB in the environment and discuss the possible function of the magnetite and greigite nanoparticles. We then provide an overview of the chemical mechanisms leading to iron mineralization in MTB. Finally, we update the methods used for the detection of MTB crystals in sedimentary rocks and present their occurrences in the geological record.
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Affiliation(s)
- Matthieu Amor
- Aix-Marseille University, CNRS, CEA, UMR7265 Institute of Biosciences and Biotechnologies of Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, F-13108, France
| | - François P Mathon
- Aix-Marseille University, CNRS, CEA, UMR7265 Institute of Biosciences and Biotechnologies of Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, F-13108, France.,Institut de Physique du Globe de Paris, Université de Paris, CNRS, Paris, F-75005, France
| | - Caroline L Monteil
- Aix-Marseille University, CNRS, CEA, UMR7265 Institute of Biosciences and Biotechnologies of Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, F-13108, France
| | - Vincent Busigny
- Institut de Physique du Globe de Paris, Université de Paris, CNRS, Paris, F-75005, France.,Institut Universitaire de France, Paris, 75005, France
| | - Christopher T Lefevre
- Aix-Marseille University, CNRS, CEA, UMR7265 Institute of Biosciences and Biotechnologies of Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, F-13108, France
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Division of labor and growth during electrical cooperation in multicellular cable bacteria. Proc Natl Acad Sci U S A 2020; 117:5478-5485. [PMID: 32094191 PMCID: PMC7071850 DOI: 10.1073/pnas.1916244117] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cable bacteria form centimeter-long, multicellular filaments whose energy metabolism involves cooperation among cells that separately perform oxidation of the electron donor and reduction of the electron acceptor. This cooperative division of labor is facilitated via long-range electrical currents that run from cell to cell along a network of conductive fibers. Here we show that biomass synthesis shows a surprising asymmetry along the filament: only the cells oxidizing the electron donor conserve energy for growth, while the other cells reduce electron acceptors without biosynthesis. Our study hence provides insights into the physiology of an unconventional chemolithotroph, which forms a multicellular electrically connected system with unique functional differentiation, integration, and coordination. Multicellularity is a key evolutionary innovation, leading to coordinated activity and resource sharing among cells, which generally occurs via the physical exchange of chemical compounds. However, filamentous cable bacteria display a unique metabolism in which redox transformations in distant cells are coupled via long-distance electron transport rather than an exchange of chemicals. This challenges our understanding of organismal functioning, as the link among electron transfer, metabolism, energy conservation, and filament growth in cable bacteria remains enigmatic. Here, we show that cells within individual filaments of cable bacteria display a remarkable dichotomy in biosynthesis that coincides with redox zonation. Nanoscale secondary ion mass spectrometry combined with 13C (bicarbonate and propionate) and 15N-ammonia isotope labeling reveals that cells performing sulfide oxidation in deeper anoxic horizons have a high assimilation rate, whereas cells performing oxygen reduction in the oxic zone show very little or no label uptake. Accordingly, oxygen reduction appears to merely function as a mechanism to quickly dispense of electrons with little to no energy conservation, while biosynthesis and growth are restricted to sulfide-respiring cells. Still, cells can immediately switch roles when redox conditions change, and show no differentiation, which suggests that the “community service” performed by the cells in the oxic zone is only temporary. Overall, our data reveal a division of labor and electrical cooperation among cells that has not been seen previously in multicellular organisms.
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Hussain S, Min Z, Xiuxiu Z, Khan MH, Lifeng L, Hui C. Significance of Fe(II) and environmental factors on carbon-fixing bacterial community in two paddy soils. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 182:109456. [PMID: 31398779 DOI: 10.1016/j.ecoenv.2019.109456] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 07/15/2019] [Accepted: 07/18/2019] [Indexed: 05/20/2023]
Abstract
The seasonal flooding and drainage process affect the paddy soils, the existence of the iron state either Fe(III) or Fe(II) is the main redox system of paddy soil. Its morphological transformation affects the redox nature of paddy soils, which also affects the distribution of bacterial community diversity. This study based on molecular biological methods (qPCR, Illumina MiSeq sequencing technique) to investigate the effect of Fe(II) and environmental factors on cbbM genes containing carbon fixing microbes. Both Eh5 and pH were reduced with Fe(II) concentrations. The Fe(II) addition significantly affects the cbbM gene copy number in both texture soils. In loamy soil, cbbM gene copy number increased with high addition of Fe(II), while both low and high concentrations significantly reduced the cbbM gene copy number in sandy soil. Chemotrophic bacterial abundance significantly increased by 79.7% and 54.8% with high and low Fe(II) addition in loamy soil while in sandy soil its abundance decreased by 53% and 54% with the low and high Fe(II) accumulation. The phototrophic microbial community increased by 37.8% with low Fe(II) concentration and decreased by 16.2% with a high concentration in loamy soil, while in sandy soil increased by 21% and 14.3% in sandy soil with low and high Fe(II) addition. Chemoheterotrophic carbon fixing bacterial abundance decreased with the Fe(II) accumulation in both soil textures in loamy soil its abundance decreased by 5.8% and 24.8%, while in sand soil 15.7% and 12.8% with low and high Fe(II) concentrations. The Fe(II) concentration and soil textures maybe two of the major factors to shape the bacterial community structure in paddy soils. These results provide a scientific basis for management of paddy soil fertility and it can be beneficial to take measures to ease the greenhouse gases effect.
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Affiliation(s)
- Sarfraz Hussain
- College of Life Sciences/Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhang Min
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhu Xiuxiu
- College of Life Sciences/Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Muzammil Hassan Khan
- College of Life Sciences/Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Li Lifeng
- College of Life Sciences/Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Cao Hui
- College of Life Sciences/Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China.
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Koziaeva VV, Rusakova SA, Slobodova NV, Uzun M, Kolganova TV, Skryabin KG, Grouzdev DS. Magnetospirillum kuznetsovii sp. nov., a novel magnetotactic bacterium isolated from a lake in the Moscow region. Int J Syst Evol Microbiol 2019; 69:1953-1959. [DOI: 10.1099/ijsem.0.003408] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Veronika V. Koziaeva
- 1Institute of Bioengineering, Federal Research Center of Biotechnology of the Russian Academy of Sciences, 119071, Leninsky Ave 33, bld. 2, Moscow, Russia
| | - Svetlana A. Rusakova
- 1Institute of Bioengineering, Federal Research Center of Biotechnology of the Russian Academy of Sciences, 119071, Leninsky Ave 33, bld. 2, Moscow, Russia
| | - Natalia V. Slobodova
- 1Institute of Bioengineering, Federal Research Center of Biotechnology of the Russian Academy of Sciences, 119071, Leninsky Ave 33, bld. 2, Moscow, Russia
| | - Maria Uzun
- 1Institute of Bioengineering, Federal Research Center of Biotechnology of the Russian Academy of Sciences, 119071, Leninsky Ave 33, bld. 2, Moscow, Russia
- 2Faculty of Biology, Lomonosov Moscow State University, 119991, Leninskie Gory 1-12, Moscow, Russia
| | - Tatiana V. Kolganova
- 1Institute of Bioengineering, Federal Research Center of Biotechnology of the Russian Academy of Sciences, 119071, Leninsky Ave 33, bld. 2, Moscow, Russia
| | - Konstantin G. Skryabin
- 1Institute of Bioengineering, Federal Research Center of Biotechnology of the Russian Academy of Sciences, 119071, Leninsky Ave 33, bld. 2, Moscow, Russia
| | - Denis S. Grouzdev
- 1Institute of Bioengineering, Federal Research Center of Biotechnology of the Russian Academy of Sciences, 119071, Leninsky Ave 33, bld. 2, Moscow, Russia
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Matturro B, Cruz Viggi C, Aulenta F, Rossetti S. Cable Bacteria and the Bioelectrochemical Snorkel: The Natural and Engineered Facets Playing a Role in Hydrocarbons Degradation in Marine Sediments. Front Microbiol 2017; 8:952. [PMID: 28611751 PMCID: PMC5447156 DOI: 10.3389/fmicb.2017.00952] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 05/12/2017] [Indexed: 11/13/2022] Open
Abstract
The composition and metabolic traits of the microbial communities acting in an innovative bioelectrochemical system were here investigated. The system, known as Oil Spill Snorkel, was recently developed to stimulate the oxidative biodegradation of petroleum hydrocarbons in anoxic marine sediments. Next Generation Sequencing was used to describe the microbiome of the bulk sediment and of the biofilm growing attached to the surface of the electrode. The analysis revealed that sulfur cycling primarily drives the microbial metabolic activities occurring in the bioelectrochemical system. In the anoxic zone of the contaminated marine sediment, petroleum hydrocarbon degradation occurred under sulfate-reducing conditions and was lead by different families of Desulfobacterales (46% of total OTUs). Remarkably, the occurrence of filamentous Desulfubulbaceae, known to be capable to vehicle electrons deriving from sulfide oxidation to oxygen serving as a spatially distant electron acceptor, was demonstrated. Differently from the sediment, which was mostly colonized by Deltaproteobacteria, the biofilm at the anode hosted, at high extent, members of Alphaproteobacteria (59%) mostly affiliated to Rhodospirillaceae family (33%) and including several known sulfur- and sulfide-oxidizing genera. Overall, we showed the occurrence in the system of a variety of electroactive microorganisms able to sustain the contaminant biodegradation alone or by means of an external conductive support through the establishment of a bioelectrochemical connection between two spatially separated redox zones and the preservation of an efficient sulfur cycling.
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Magnetotactic bacteria as potential sources of bioproducts. Mar Drugs 2015; 13:389-430. [PMID: 25603340 PMCID: PMC4306944 DOI: 10.3390/md13010389] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 12/17/2014] [Indexed: 11/16/2022] Open
Abstract
Magnetotactic bacteria (MTB) produce intracellular organelles called magnetosomes which are magnetic nanoparticles composed of magnetite (Fe3O4) or greigite (Fe3S4) enveloped by a lipid bilayer. The synthesis of a magnetosome is through a genetically controlled process in which the bacterium has control over the composition, direction of crystal growth, and the size and shape of the mineral crystal. As a result of this control, magnetosomes have narrow and uniform size ranges, relatively specific magnetic and crystalline properties, and an enveloping biological membrane. These features are not observed in magnetic particles produced abiotically and thus magnetosomes are of great interest in biotechnology. Most currently described MTB have been isolated from saline or brackish environments and the availability of their genomes has contributed to a better understanding and culturing of these fastidious microorganisms. Moreover, genome sequences have allowed researchers to study genes related to magnetosome production for the synthesis of magnetic particles for use in future commercial and medical applications. Here, we review the current information on the biology of MTB and apply, for the first time, a genome mining strategy on these microorganisms to search for secondary metabolite synthesis genes. More specifically, we discovered that the genome of the cultured MTB Magnetovibrio blakemorei, among other MTB, contains several metabolic pathways for the synthesis of secondary metabolites and other compounds, thereby raising the possibility of the co-production of new bioactive molecules along with magnetosomes by this species.
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Abstract
Magnetotactic bacteria (MTB) are widespread, motile, diverse prokaryotes that biomineralize a unique organelle called the magnetosome. Magnetosomes consist of a nano-sized crystal of a magnetic iron mineral that is enveloped by a lipid bilayer membrane. In cells of almost all MTB, magnetosomes are organized as a well-ordered chain. The magnetosome chain causes the cell to behave like a motile, miniature compass needle where the cell aligns and swims parallel to magnetic field lines. MTB are found in almost all types of aquatic environments, where they can account for an important part of the bacterial biomass. The genes responsible for magnetosome biomineralization are organized as clusters in the genomes of MTB, in some as a magnetosome genomic island. The functions of a number of magnetosome genes and their associated proteins in magnetosome synthesis and construction of the magnetosome chain have now been elucidated. The origin of magnetotaxis appears to be monophyletic; that is, it developed in a common ancestor to all MTB, although horizontal gene transfer of magnetosome genes also appears to play a role in their distribution. The purpose of this review, based on recent progress in this field, is focused on the diversity and the ecology of the MTB and also the evolution and transfer of the molecular determinants involved in magnetosome formation.
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12
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Succession of cable bacteria and electric currents in marine sediment. ISME JOURNAL 2014; 8:1314-22. [PMID: 24451206 DOI: 10.1038/ismej.2013.239] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 11/12/2013] [Accepted: 12/04/2013] [Indexed: 11/08/2022]
Abstract
Filamentous Desulfobulbaceae have been reported to conduct electrons over centimetre-long distances, thereby coupling oxygen reduction at the surface of marine sediment to sulphide oxidation in sub-surface layers. To understand how these 'cable bacteria' establish and sustain electric conductivity, we followed a population for 53 days after exposing sulphidic sediment with initially no detectable filaments to oxygen. After 10 days, cable bacteria and electric currents were established throughout the top 15 mm of the sediment, and after 21 days the filament density peaked with a total length of 2 km cm(-2). Cells elongated and divided at all depths with doubling times over the first 10 days of <20 h. Active, oriented movement must have occurred to explain the separation of O2 and H2S by 15 mm. Filament diameters varied from 0.4-1.7 μm, with a general increase over time and depth, and yet they shared 16S rRNA sequence identity of >98%. Comparison of the increase in biovolume and electric current density suggested high cellular growth efficiency. While the vertical expansion of filaments continued over time and reached 30 mm, the electric current density and biomass declined after 13 and 21 days, respectively. This might reflect a breakdown of short filaments as their solid sulphide sources became depleted in the top layers of the anoxic zone. In conclusion, cable bacteria combine rapid and efficient growth with oriented movement to establish and exploit the spatially separated half-reactions of sulphide oxidation and oxygen consumption.
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MacGregor BJ, Biddle JF, Harbort C, Matthysse AG, Teske A. Sulfide oxidation, nitrate respiration, carbon acquisition, and electron transport pathways suggested by the draft genome of a single orange Guaymas Basin Beggiatoa (Cand. Maribeggiatoa) sp. filament. Mar Genomics 2013; 11:53-65. [PMID: 24012537 DOI: 10.1016/j.margen.2013.08.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 08/12/2013] [Accepted: 08/12/2013] [Indexed: 12/27/2022]
Abstract
A near-complete draft genome has been obtained for a single vacuolated orange Beggiatoa (Cand. Maribeggiatoa) filament from a Guaymas Basin seafloor microbial mat, the third relatively complete sequence for the Beggiatoaceae. Possible pathways for sulfide oxidation; nitrate respiration; inorganic carbon fixation by both Type II RuBisCO and the reductive tricarboxylic acid cycle; acetate and possibly formate uptake; and energy-generating electron transport via both oxidative phosphorylation and the Rnf complex are discussed here. A role in nitrite reduction is suggested for an abundant orange cytochrome produced by the Guaymas strain; this has a possible homolog in Beggiatoa (Cand. Isobeggiatoa) sp. PS, isolated from marine harbor sediment, but not Beggiatoa alba B18LD, isolated from a freshwater rice field ditch. Inferred phylogenies for the Calvin-Benson-Bassham (CBB) cycle and the reductive (rTCA) and oxidative (TCA) tricarboxylic acid cycles suggest that genes encoding succinate dehydrogenase and enzymes for carboxylation and/or decarboxylation steps (including RuBisCO) may have been introduced to (or exported from) one or more of the three genomes by horizontal transfer, sometimes by different routes. Sequences from the two marine strains are generally more similar to each other than to sequences from the freshwater strain, except in the case of RuBisCO: only the Guaymas strain encodes a Type II enzyme, which (where studied) discriminates less against oxygen than do Type I RuBisCOs. Genes subject to horizontal transfer may represent key steps for adaptation to factors such as oxygen and carbon dioxide concentration, organic carbon availability, and environmental variability.
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Affiliation(s)
- Barbara J MacGregor
- Department of Marine Sciences, University of North Carolina - Chapel Hill, Chapel Hill, NC 27599, USA.
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Insight into the evolution of magnetotaxis in Magnetospirillum spp., based on mam gene phylogeny. Appl Environ Microbiol 2012; 78:7238-48. [PMID: 22865076 DOI: 10.1128/aem.01951-12] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrioid- to helical-shaped magnetotactic bacteria phylogenetically related to the genus Magnetospirillum were isolated in axenic cultures from a number of freshwater and brackish environments located in the southwestern United States. Based on 16S rRNA gene sequences, most of the new isolates represent new Magnetospirillum species or new strains of known Magnetospirillum species, while one isolate appears to represent a new genus basal to Magnetospirillum. Partial sequences of conserved mam genes, genes reported to be involved in the magnetosome and magnetosome chain formation, and form II of the ribulose-1,5-bisphosphate carboxylase/oxygenase gene (cbbM) were determined in the new isolates and compared. The cbbM gene was chosen for comparison because it is not involved in magnetosome synthesis; it is highly conserved and is present in all but possibly one of the genomes of the magnetospirilla and the new isolates. Phylogenies based on 16S rRNA, cbbM, and mam gene sequences were reasonably congruent, indicating that the genes involved in magnetotaxis were acquired by a common ancestor of the Magnetospirillum clade. However, in one case, magnetosome genes might have been acquired through horizontal gene transfer. Our results also extend the known diversity of the Magnetospirillum group and show that they are widespread in freshwater environments.
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Dzyuba MV, Mardanov AV, Beletskii AV, Kolganova TV, Sukhacheva MV, Shelenkov AA, Gorlenko VM, Kuznetsov BB, Skryabin KG. Reconstruction of iron metabolism pathways of bacteria Magnetospirillum aberrantis SpK spp. based on sequenced genome analysis. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2012; 444:202-5. [PMID: 22760625 DOI: 10.1134/s001249661203009x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Indexed: 11/23/2022]
Affiliation(s)
- M V Dzyuba
- Bioengineering Center, Russian Academy of Sciences, Moscow, Russia
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Postec A, Tapia N, Bernadac A, Joseph M, Davidson S, Wu LF, Ollivier B, Pradel N. Magnetotactic bacteria in microcosms originating from the French Mediterranean Coast subjected to oil industry activities. MICROBIAL ECOLOGY 2012; 63:1-11. [PMID: 21766218 DOI: 10.1007/s00248-011-9910-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 06/30/2011] [Indexed: 05/31/2023]
Abstract
Magnetotactic bacteria (MTB) mineralize nanosized magnetite or greigite crystals within cells and thus play an important role in the biogeochemical process. Despite decades of research, knowledge of MTB distribution and ecology, notably in areas subjected to oil industry activities, is still limited. In the present study, we investigated the presence of MTB in the Gulf of Fos, French Mediterranean coast, which is subjected to intensive oil industry activities. Microcosms containing sediments/water (1:2, v/v) from several sampling sites were monitored over several weeks. The presence of MTB was revealed in five of eight sites. Diverse and numerous MTB were revealed particularly from one site (named CAR), whilst temporal variations of a homogenous magnetotactic cocci population was shown within the LAV site microcosm over a 4-month period. Phylogenetic analysis revealed that they belonged to Alphaproteobacteria, and a novel genus from the LAV site was evidenced. Among the physicochemical parameters measured, a correlation was shown between the variation of MTB abundance in microcosms and the redox state of sulphur compounds.
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Affiliation(s)
- Anne Postec
- IRD, UMR_D 180, Université Aix Marseille, ESIL case 925, 163 Avenue de Luminy, 13288, Marseille Cedex 9, France
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Gorlenko VM, Dzyuba MV, Maleeva AN, Panteleeva AN, Kolganova TV, Kuznetsov BB. Magnetospirillum aberrantis sp. nov., a new freshwater bacterium with magnetic inclusions. Microbiology (Reading) 2011. [DOI: 10.1134/s0026261711050055] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Srinivasan V, Morowitz HJ, Huber H. What is an autotroph? Arch Microbiol 2011; 194:135-40. [DOI: 10.1007/s00203-011-0755-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2011] [Revised: 07/24/2011] [Accepted: 09/13/2011] [Indexed: 10/17/2022]
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Lefèvre CT, Viloria N, Schmidt ML, Pósfai M, Frankel RB, Bazylinski DA. Novel magnetite-producing magnetotactic bacteria belonging to the Gammaproteobacteria. ISME JOURNAL 2011; 6:440-50. [PMID: 21776027 DOI: 10.1038/ismej.2011.97] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Two novel magnetotactic bacteria (MTB) were isolated from sediment and water collected from the Badwater Basin, Death Valley National Park and southeastern shore of the Salton Sea, respectively, and were designated as strains BW-2 and SS-5, respectively. Both organisms are rod-shaped, biomineralize magnetite, and are motile by means of flagella. The strains grow chemolithoautotrophically oxidizing thiosulfate and sulfide microaerobically as electron donors, with thiosulfate oxidized stoichiometrically to sulfate. They appear to utilize the Calvin-Benson-Bassham cycle for autotrophy based on ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) activity and the presence of partial sequences of RubisCO genes. Strains BW-2 and SS-5 biomineralize chains of octahedral magnetite crystals, although the crystals of SS-5 are elongated. Based on 16S rRNA gene sequences, both strains are phylogenetically affiliated with the Gammaproteobacteria class. Strain SS-5 belongs to the order Chromatiales; the cultured bacterium with the highest 16S rRNA gene sequence identity to SS-5 is Thiohalocapsa marina (93.0%). Strain BW-2 clearly belongs to the Thiotrichales; interestingly, the organism with the highest 16S rRNA gene sequence identity to this strain is Thiohalospira alkaliphila (90.2%), which belongs to the Chromatiales. Each strain represents a new genus. This is the first report of magnetite-producing MTB phylogenetically associated with the Gammaproteobacteria. This finding is important in that it significantly expands the phylogenetic diversity of the MTB. Physiology of these strains is similar to other MTB and continues to demonstrate their potential in nitrogen, iron, carbon and sulfur cycling in natural environments.
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Affiliation(s)
- Christopher T Lefèvre
- School of Life Sciences, University of Nevada at Las Vegas, Las Vegas, NV 89154-4004, USA
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Berg IA. Ecological aspects of the distribution of different autotrophic CO2 fixation pathways. Appl Environ Microbiol 2011; 77:1925-36. [PMID: 21216907 PMCID: PMC3067309 DOI: 10.1128/aem.02473-10] [Citation(s) in RCA: 424] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Autotrophic CO(2) fixation represents the most important biosynthetic process in biology. Besides the well-known Calvin-Benson cycle, five other totally different autotrophic mechanisms are known today. This minireview discusses the factors determining their distribution. As will be made clear, the observed diversity reflects the variety of the organisms and the ecological niches existing in nature.
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Affiliation(s)
- Ivan A Berg
- Mikrobiologie, Fakultät für Biologie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
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Magnetospirillum bellicus sp. nov., a novel dissimilatory perchlorate-reducing alphaproteobacterium isolated from a bioelectrical reactor. Appl Environ Microbiol 2010; 76:4730-7. [PMID: 20495050 DOI: 10.1128/aem.00015-10] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previously isolated dissimilatory perchlorate-reducing bacteria (DPRB) have been primarily affiliated with the Betaproteobacteria. Enrichments from the cathodic chamber of a bioelectrical reactor (BER) inoculated from creek water in Berkeley, CA, yielded a novel organism most closely related to a previously described strain, WD (99% 16S rRNA gene identity). Strain VDY(T) has 96% 16S rRNA gene identity to both Magnetospirillum gryphiswaldense and Magnetospirillum magnetotacticum, and along with strain WD, distinguishes a clade of perchlorate-reducing Magnetospirillum species in the Alphaproteobacteria. In spite of the phylogenetic location of VDY(T), attempted PCR for the key magnetosome formation genes mamI and mamL was negative. Strain VDY(T) was motile, non-spore forming, and, in addition to perchlorate, could use oxygen, chlorate, nitrate, nitrite, and nitrous oxide as alternative electron acceptors with acetate as the electron donor. Transient chlorate accumulation occurred during respiration of perchlorate. The organism made use of fermentation end products, such as acetate and ethanol, as carbon sources and electron donors for heterotrophic growth, and in addition, strain VDY(T) could grow chemolithotrophically with hydrogen serving as the electron donor. VDY(T) contains a copy of the RuBisCo cbbM gene, which was expressed under autotrophic but not heterotrophic conditions. DNA-DNA hybridization with strain WD confirmed VDY(T) as a separate species (46.2% identity), and the name Magnetospirillum bellicus sp. nov. (DSM 21662, ATCC BAA-1730) is proposed.
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