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Abstract
Twenty-five years ago this month, Thomas Gold published a seminal manuscript suggesting the presence of a "deep, hot biosphere" in the Earth's crust. Since this publication, a considerable amount of attention has been given to the study of deep biospheres, their role in geochemical cycles, and their potential to inform on the origin of life and its potential outside of Earth. Overwhelming evidence now supports the presence of a deep biosphere ubiquitously distributed on Earth in both terrestrial and marine settings. Furthermore, it has become apparent that much of this life is dependent on lithogenically sourced high-energy compounds to sustain productivity. A vast diversity of uncultivated microorganisms has been detected in subsurface environments, and we show that H2, CH4, and CO feature prominently in many of their predicted metabolisms. Despite 25 years of intense study, key questions remain on life in the deep subsurface, including whether it is endemic and the extent of its involvement in the anaerobic formation and degradation of hydrocarbons. Emergent data from cultivation and next-generation sequencing approaches continue to provide promising new hints to answer these questions. As Gold suggested, and as has become increasingly evident, to better understand the subsurface is critical to further understanding the Earth, life, the evolution of life, and the potential for life elsewhere. To this end, we suggest the need to develop a robust network of interdisciplinary scientists and accessible field sites for long-term monitoring of the Earth's subsurface in the form of a deep subsurface microbiome initiative.
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102
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Sedano-Núñez VT, Boeren S, Stams AJM, Plugge CM. Comparative proteome analysis of propionate degradation by Syntrophobacter fumaroxidans in pure culture and in coculture with methanogens. Environ Microbiol 2018; 20:1842-1856. [PMID: 29611893 PMCID: PMC5947623 DOI: 10.1111/1462-2920.14119] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 03/20/2018] [Accepted: 03/24/2018] [Indexed: 11/28/2022]
Abstract
Syntrophobacter fumaroxidans is a sulfate-reducing bacterium able to grow on propionate axenically or in syntrophic interaction with methanogens or other sulfate-reducing bacteria. We performed a proteome analysis of S. fumaroxidans growing with propionate axenically with sulfate or fumarate, and in syntrophy with Methanospirillum hungatei, Methanobacterium formicicum or Desulfovibrio desulfuricans. Special attention was put on the role of hydrogen and formate in interspecies electron transfer (IET) and energy conservation. Formate dehydrogenase Fdh1 and hydrogenase Hox were the main confurcating enzymes used for energy conservation. In the periplasm, Fdh2 and hydrogenase Hyn play an important role in reverse electron transport associated with succinate oxidation. Periplasmic Fdh3 and Fdh5 were involved in IET. The sulfate reduction pathway was poorly regulated and many enzymes associated with sulfate reduction (Sat, HppA, AprAB, DsrAB and DsrC) were abundant even at conditions where sulfate was not present. Proteins similar to heterodisulfide reductases (Hdr) were abundant. Hdr/Flox was detected in all conditions while HdrABC/HdrL was exclusively detected when sulfate was available; these complexes most likely confurcate electrons. Our results suggest that S. fumaroxidans mainly used formate for electron release and that different confurcating mechanisms were used in its sulfidogenic metabolism.
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Affiliation(s)
- Vicente T Sedano-Núñez
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, Wageningen, The Netherlands
| | - Sjef Boeren
- Laboratory of Biochemistry, Wageningen University & Research, Stippeneng 4, Wageningen, The Netherlands
| | - Alfons J M Stams
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, Wageningen, The Netherlands.,Centre of Biological Engineering, University of Minho, Campus de Gualtar, Braga, 4710-057, Portugal
| | - Caroline M Plugge
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, Wageningen, The Netherlands
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103
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Sousa FM, Pereira JG, Marreiros BC, Pereira MM. Taxonomic distribution, structure/function relationship and metabolic context of the two families of sulfide dehydrogenases: SQR and FCSD. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:742-753. [PMID: 29684324 DOI: 10.1016/j.bbabio.2018.04.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 03/28/2018] [Accepted: 04/15/2018] [Indexed: 12/26/2022]
Abstract
Hydrogen sulfide (H2S) is a versatile molecule with different functions in living organisms: it can work as a metabolite of sulfur and energetic metabolism or as a signaling molecule in higher Eukaryotes. H2S is also highly toxic since it is able to inhibit heme cooper oxygen reductases, preventing oxidative phosphorylation. Due to the fact that it can both inhibit and feed the respiratory chain, the immediate role of H2S on energy metabolism crucially relies on its bioavailability, meaning that studying the central players involved in the H2S homeostasis is key for understanding sulfide metabolism. Two different enzymes with sulfide oxidation activity (sulfide dehydrogenases) are known: flavocytochrome c sulfide dehydrogenase (FCSD), a sulfide:cytochrome c oxidoreductase; and sulfide:quinone oxidoreductase (SQR). In this work we performed a thorough bioinformatic study of SQRs and FCSDs and integrated all published data. We systematized several properties of these proteins: (i) nature of flavin binding, (ii) capping loops and (iii) presence of key amino acid residues. We also propose an update to the SQR classification system and discuss the role of these proteins in sulfur metabolism.
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Affiliation(s)
- Filipe M Sousa
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da Republica EAN, 2780-157 Oeiras, Portugal
| | - Juliana G Pereira
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da Republica EAN, 2780-157 Oeiras, Portugal
| | - Bruno C Marreiros
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da Republica EAN, 2780-157 Oeiras, Portugal
| | - Manuela M Pereira
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da Republica EAN, 2780-157 Oeiras, Portugal; University of Lisbon, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal.
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104
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Krukenberg V, Riedel D, Gruber-Vodicka HR, Buttigieg PL, Tegetmeyer HE, Boetius A, Wegener G. Gene expression and ultrastructure of meso- and thermophilic methanotrophic consortia. Environ Microbiol 2018; 20:1651-1666. [PMID: 29468803 PMCID: PMC5947290 DOI: 10.1111/1462-2920.14077] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 02/15/2018] [Accepted: 02/15/2018] [Indexed: 11/27/2022]
Abstract
The sulfate‐dependent, anaerobic oxidation of methane (AOM) is an important sink for methane in marine environments. It is carried out between anaerobic methanotrophic archaea (ANME) and sulfate‐reducing bacteria (SRB) living in syntrophic partnership. In this study, we compared the genomes, gene expression patterns and ultrastructures of three phylogenetically different microbial consortia found in hydrocarbon‐rich environments under different temperature regimes: ANME‐1a/HotSeep‐1 (60°C), ANME‐1a/Seep‐SRB2 (37°C) and ANME‐2c/Seep‐SRB2 (20°C). All three ANME encode a reverse methanogenesis pathway: ANME‐2c encodes all enzymes, while ANME‐1a lacks the gene for N5,N10‐methylene tetrahydromethanopterin reductase (mer) and encodes a methylenetetrahydrofolate reductase (Met). The bacterial partners contain the genes encoding the canonical dissimilatory sulfate reduction pathway. During AOM, all three consortia types highly expressed genes encoding for the formation of flagella or type IV pili and/or c‐type cytochromes, some predicted to be extracellular. ANME‐2c expressed potentially extracellular cytochromes with up to 32 hemes, whereas ANME‐1a and SRB expressed less complex cytochromes (≤ 8 and ≤ 12 heme respectively). The intercellular space of all consortia showed nanowire‐like structures and heme‐rich areas. These features are proposed to enable interspecies electron exchange, hence suggesting that direct electron transfer is a common mechanism to sulfate‐dependent AOM, and that both partners synthesize molecules to enable it.
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Affiliation(s)
- Viola Krukenberg
- Max Planck Institute for Marine Microbiology, Bremen, 28359, Germany
| | - Dietmar Riedel
- Max Planck Institute for Biophysical Chemistry, Göttingen, 37077, Germany
| | | | - Pier Luigi Buttigieg
- Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Bremerhaven, 27570, Germany
| | - Halina E Tegetmeyer
- Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Bremerhaven, 27570, Germany.,Center for Biotechnology, Bielefeld University, Bielefeld, 33615, Germany
| | - Antje Boetius
- Max Planck Institute for Marine Microbiology, Bremen, 28359, Germany.,Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Bremerhaven, 27570, Germany.,MARUM, Center for Marine Environmental Sciences, University Bremen, Bremen, 28359, Germany
| | - Gunter Wegener
- Max Planck Institute for Marine Microbiology, Bremen, 28359, Germany.,MARUM, Center for Marine Environmental Sciences, University Bremen, Bremen, 28359, Germany
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105
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Flowers JJ, Richards MA, Baliga N, Meyer B, Stahl DA. Constraint-based modelling captures the metabolic versatility of Desulfovibrio vulgaris. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:190-201. [PMID: 29377633 DOI: 10.1111/1758-2229.12619] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 01/18/2018] [Indexed: 06/07/2023]
Abstract
A refined Desulfovibrio vulgaris Hildenborough flux balance analysis (FBA) model (iJF744) was developed, incorporating 1016 reactions that include 744 genes and 951 metabolites. A draft model was first developed through automatic model reconstruction using the ModelSeed Server and then curated based on existing literature. The curated model was further refined by incorporating three recently proposed redox reactions involving the Hdr-Flx and Qmo complexes and a lactate dehydrogenase (LdhAB, DVU 3027-3028) indicated by mutation and transcript analyses to serve electron transfer reactions central to syntrophic and respiratory growth. Eight different variations of this model were evaluated by comparing model predictions to experimental data determined for four different growth conditions - three for sulfate respiration (with lactate, pyruvate or H2 /CO2 -acetate) and one for fermentation in syntrophic coculture. The final general model supports (i) a role for Hdr-Flx in the oxidation of DsrC and ferredoxin, and reduction of NAD+ in a flavin-based electron confurcating reaction sequence, (ii) a function of the Qmo complex in receiving electrons from the menaquinone pool and potentially from ferredoxin to reduce APS and (iii) a reduction of the soluble DsrC by LdhAB and a function of DsrC in electron transfer reactions other than sulfite reduction.
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Affiliation(s)
- Jason J Flowers
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA
| | | | | | - Birte Meyer
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA
| | - David A Stahl
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA
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106
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Buckel W, Thauer RK. Flavin-Based Electron Bifurcation, Ferredoxin, Flavodoxin, and Anaerobic Respiration With Protons (Ech) or NAD + (Rnf) as Electron Acceptors: A Historical Review. Front Microbiol 2018; 9:401. [PMID: 29593673 PMCID: PMC5861303 DOI: 10.3389/fmicb.2018.00401] [Citation(s) in RCA: 199] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 02/21/2018] [Indexed: 12/19/2022] Open
Abstract
Flavin-based electron bifurcation is a newly discovered mechanism, by which a hydride electron pair from NAD(P)H, coenzyme F420H2, H2, or formate is split by flavoproteins into one-electron with a more negative reduction potential and one with a more positive reduction potential than that of the electron pair. Via this mechanism microorganisms generate low- potential electrons for the reduction of ferredoxins (Fd) and flavodoxins (Fld). The first example was described in 2008 when it was found that the butyryl-CoA dehydrogenase-electron-transferring flavoprotein complex (Bcd-EtfAB) of Clostridium kluyveri couples the endergonic reduction of ferredoxin (E0′ = −420 mV) with NADH (−320 mV) to the exergonic reduction of crotonyl-CoA to butyryl-CoA (−10 mV) with NADH. The discovery was followed by the finding of an electron-bifurcating Fd- and NAD-dependent [FeFe]-hydrogenase (HydABC) in Thermotoga maritima (2009), Fd-dependent transhydrogenase (NfnAB) in various bacteria and archaea (2010), Fd- and H2-dependent heterodisulfide reductase (MvhADG-HdrABC) in methanogenic archaea (2011), Fd- and NADH-dependent caffeyl-CoA reductase (CarCDE) in Acetobacterium woodii (2013), Fd- and NAD-dependent formate dehydrogenase (HylABC-FdhF2) in Clostridium acidi-urici (2013), Fd- and NADP-dependent [FeFe]-hydrogenase (HytA-E) in Clostridium autoethanogrenum (2013), Fd(?)- and NADH-dependent methylene-tetrahydrofolate reductase (MetFV-HdrABC-MvhD) in Moorella thermoacetica (2014), Fd- and NAD-dependent lactate dehydrogenase (LctBCD) in A. woodii (2015), Fd- and F420H2-dependent heterodisulfide reductase (HdrA2B2C2) in Methanosarcina acetivorans (2017), and Fd- and NADH-dependent ubiquinol reductase (FixABCX) in Azotobacter vinelandii (2017). The electron-bifurcating flavoprotein complexes known to date fall into four groups that have evolved independently, namely those containing EtfAB (CarED, LctCB, FixBA) with bound FAD, a NuoF homolog (HydB, HytB, or HylB) harboring FMN, NfnB with bound FAD, or HdrA harboring FAD. All these flavoproteins are cytoplasmic except for the membrane-associated protein FixABCX. The organisms—in which they have been found—are strictly anaerobic microorganisms except for the aerobe A. vinelandii. The electron-bifurcating complexes are involved in a variety of processes such as butyric acid fermentation, methanogenesis, acetogenesis, anaerobic lactate oxidation, dissimilatory sulfate reduction, anaerobic- dearomatization, nitrogen fixation, and CO2 fixation. They contribute to energy conservation via the energy-converting ferredoxin: NAD+ reductase complex Rnf or the energy-converting ferredoxin-dependent hydrogenase complex Ech. This Review describes how this mechanism was discovered.
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Affiliation(s)
- Wolfgang Buckel
- Laboratory for Microbiology, Faculty of Biology, Philipps-Universität Marburg, Marburg, Germany
| | - Rudolf K Thauer
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
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107
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Marietou A, Røy H, Jørgensen BB, Kjeldsen KU. Sulfate Transporters in Dissimilatory Sulfate Reducing Microorganisms: A Comparative Genomics Analysis. Front Microbiol 2018; 9:309. [PMID: 29551997 PMCID: PMC5840216 DOI: 10.3389/fmicb.2018.00309] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 02/09/2018] [Indexed: 12/31/2022] Open
Abstract
The first step in the sulfate reduction pathway is the transport of sulfate across the cell membrane. This uptake has a major effect on sulfate reduction rates. Much of the information available on sulfate transport was obtained by studies on assimilatory sulfate reduction, where sulfate transporters were identified among several types of protein families. Despite our growing knowledge on the physiology of dissimilatory sulfate-reducing microorganisms (SRM) there are no studies identifying the proteins involved in sulfate uptake in members of this ecologically important group of anaerobes. We surveyed the complete genomes of 44 sulfate-reducing bacteria and archaea across six phyla and identified putative sulfate transporter encoding genes from four out of the five surveyed protein families based on homology. We did not find evidence that ABC-type transporters (SulT) are involved in the uptake of sulfate in SRM. We speculate that members of the CysP sulfate transporters could play a key role in the uptake of sulfate in thermophilic SRM. Putative CysZ-type sulfate transporters were present in all genomes examined suggesting that this overlooked group of sulfate transporters might play a role in sulfate transport in dissimilatory sulfate reducers alongside SulP. Our in silico analysis highlights several targets for further molecular studies in order to understand this key step in the metabolism of SRMs.
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Affiliation(s)
- Angeliki Marietou
- Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Hans Røy
- Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Bo B Jørgensen
- Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Kasper U Kjeldsen
- Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
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108
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Rice Paddy Nitrospirae Carry and Express Genes Related to Sulfate Respiration: Proposal of the New Genus "Candidatus Sulfobium". Appl Environ Microbiol 2018; 84:AEM.02224-17. [PMID: 29247059 PMCID: PMC5812927 DOI: 10.1128/aem.02224-17] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 12/08/2017] [Indexed: 01/16/2023] Open
Abstract
Nitrospirae spp. distantly related to thermophilic, sulfate-reducing Thermodesulfovibrio species are regularly observed in environmental surveys of anoxic marine and freshwater habitats. Here we present a metaproteogenomic analysis of Nitrospirae bacterium Nbg-4 as a representative of this clade. Its genome was assembled from replicated metagenomes of rice paddy soil that was used to grow rice in the presence and absence of gypsum (CaSO4·2H2O). Nbg-4 encoded the full pathway of dissimilatory sulfate reduction and showed expression of this pathway in gypsum-amended anoxic bulk soil as revealed by parallel metaproteomics. In addition, Nbg-4 encoded the full pathway of dissimilatory nitrate reduction to ammonia (DNRA), with expression of its first step being detected in bulk soil without gypsum amendment. The relative abundances of Nbg-4 were similar under both treatments, indicating that Nbg-4 maintained stable populations while shifting its energy metabolism. Whether Nbg-4 is a strict sulfate reducer or can couple sulfur oxidation to DNRA by operating the pathway of dissimilatory sulfate reduction in reverse could not be resolved. Further genome reconstruction revealed the potential to utilize butyrate, formate, H2, or acetate as an electron donor; the Wood-Ljungdahl pathway was expressed under both treatments. Comparison to publicly available Nitrospirae genome bins revealed the pathway for dissimilatory sulfate reduction also in related Nitrospirae recovered from groundwater. Subsequent phylogenomics showed that such microorganisms form a novel genus within the Nitrospirae, with Nbg-4 as a representative species. Based on the widespread occurrence of this novel genus, we propose for Nbg-4 the name “Candidatus Sulfobium mesophilum,” gen. nov., sp. nov. IMPORTANCE Rice paddies are indispensable for the food supply but are a major source of the greenhouse gas methane. If it were not counterbalanced by cryptic sulfur cycling, methane emission from rice paddy fields would be even higher. However, the microorganisms involved in this sulfur cycling are little understood. By using an environmental systems biology approach with Italian rice paddy soil, we could retrieve the population genome of a novel member of the phylum Nitrospirae. This microorganism encoded the full pathway of dissimilatory sulfate reduction and expressed it in anoxic paddy soil under sulfate-enriched conditions. Phylogenomics and comparison to the results of environmental surveys showed that such microorganisms are actually widespread in freshwater and marine environments. At the same time, they represent an undiscovered genus within the little-explored phylum Nitrospirae. Our results will be important for the design of enrichment strategies and postgenomic studies to further understanding of the contribution of these novel Nitrospirae spp. to the global sulfur cycle.
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109
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Wenk CB, Wing BA, Halevy I. Electron carriers in microbial sulfate reduction inferred from experimental and environmental sulfur isotope fractionations. THE ISME JOURNAL 2018; 12:495-507. [PMID: 29087380 PMCID: PMC5776465 DOI: 10.1038/ismej.2017.185] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 08/26/2017] [Accepted: 09/24/2017] [Indexed: 01/29/2023]
Abstract
Dissimilatory sulfate reduction (DSR) has been a key process influencing the global carbon cycle, atmospheric composition and climate for much of Earth's history, yet the energy metabolism of sulfate-reducing microbes remains poorly understood. Many organisms, particularly sulfate reducers, live in low-energy environments and metabolize at very low rates, requiring specific physiological adaptations. We identify one such potential adaptation-the electron carriers selected for survival under energy-limited conditions. Employing a quantitative biochemical-isotopic model, we find that the large S isotope fractionations (>55‰) observed in a wide range of natural environments and culture experiments at low respiration rates are only possible when the standard-state Gibbs free energy (ΔG'°) of all steps during DSR is more positive than -10 kJ mol-1. This implies that at low respiration rates, only electron carriers with modestly negative reduction potentials are involved, such as menaquinone, rubredoxin, rubrerythrin or some flavodoxins. Furthermore, the constraints from S isotope fractionation imply that ferredoxins with a strongly negative reduction potential cannot be the direct electron donor to S intermediates at low respiration rates. Although most sulfate reducers have the genetic potential to express a variety of electron carriers, our results suggest that a key physiological adaptation of sulfate reducers to low-energy environments is to use electron carriers with modestly negative reduction potentials.
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Affiliation(s)
- Christine B Wenk
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel.
| | - Boswell A Wing
- Department of Geological Sciences, University of Colorado, Boulder, CO, USA
| | - Itay Halevy
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel.
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110
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Beinart RA, Beaudoin DJ, Bernhard JM, Edgcomb VP. Insights into the metabolic functioning of a multipartner ciliate symbiosis from oxygen-depleted sediments. Mol Ecol 2018; 27:1794-1807. [PMID: 29271011 DOI: 10.1111/mec.14465] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 11/21/2017] [Accepted: 11/24/2017] [Indexed: 12/13/2022]
Abstract
Symbioses between anaerobic or microaerophilic protists and prokaryotes are common in anoxic and oxygen-depleted habitats ranging from marine sediments to gastrointestinal tracts. Nevertheless, little is known about the mechanisms of metabolic interaction between partners. In these putatively syntrophic associations, consumption of fermentative end products (e.g., hydrogen) by the prokaryotic symbionts is thought to facilitate protistan anaerobic metabolism. Here, we employed metagenomic and metatranscriptomic sequencing of a microaerophilic or anaerobic karyorelictid ciliate and its prokaryotic symbionts from oxygen-depleted Santa Barbara Basin (CA, USA) sediments to assess metabolic coupling within this consortium. This sequencing confirmed the predominance of deltaproteobacterial symbionts from the Families Desulfobacteraceae and Desulfobulbaceae and suggested active symbiont reduction of host-provided sulphate, transfer of small organic molecules from host to symbionts and hydrogen cycling among the symbionts. In addition, patterns of gene expression indicated active cell division by the symbionts, their growth via autotrophic processes and nitrogen exchange with the ciliate host. Altogether, this research underscores the importance of symbiont metabolism to host fermentative metabolism and, thus, likely its success in anoxic and low-oxygen habitats, but also suggests ciliate-associated prokaryotes play a role in important biogeochemical processes.
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Affiliation(s)
- R A Beinart
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - D J Beaudoin
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - J M Bernhard
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - V P Edgcomb
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
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111
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The complete genome sequence of the rumen bacterium Butyrivibrio hungatei MB2003. Stand Genomic Sci 2017; 12:72. [PMID: 29225728 PMCID: PMC5716241 DOI: 10.1186/s40793-017-0285-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 11/23/2017] [Indexed: 12/04/2022] Open
Abstract
Butyrivibrio hungatei MB2003 was isolated from the plant-adherent fraction of rumen contents from a pasture-grazed New Zealand dairy cow, and was selected for genome sequencing in order to examine its ability to degrade plant polysaccharides. The genome of MB2003 is 3.39 Mb and consists of four replicons; a chromosome, a secondary chromosome or chromid, a megaplasmid and a small plasmid. The genome has an average G + C content of 39.7%, and encodes 2983 putative protein-coding genes. MB2003 is able to use a variety of monosaccharide substrates for growth, with acetate, butyrate and formate as the principal fermentation end-products, and the genes encoding these metabolic pathways have been identified. MB2003 is predicted to encode an extensive repertoire of CAZymes with 78 GHs, 7 CEs, 1 PL and 78 GTs. MB2003 is unable to grow on xylan or pectin, and its role in the rumen appears to be as a utilizer of monosaccharides, disaccharides and oligosaccharides made available by the degradative activities of other bacterial species.
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112
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Sousa JR, Silveira CM, Fontes P, Roma-Rodrigues C, Fernandes AR, Van Driessche G, Devreese B, Moura I, Moura JJ, Almeida MG. Understanding the response of Desulfovibrio desulfuricans ATCC 27774 to the electron acceptors nitrate and sulfate - biosynthetic costs modulate substrate selection. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:1455-1469. [DOI: 10.1016/j.bbapap.2017.07.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 07/12/2017] [Accepted: 07/21/2017] [Indexed: 11/27/2022]
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113
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Microbial community differentiation between active and inactive sulfide chimneys of the Kolumbo submarine volcano, Hellenic Volcanic Arc. Extremophiles 2017; 22:13-27. [DOI: 10.1007/s00792-017-0971-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 10/03/2017] [Indexed: 01/28/2023]
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114
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Dörries M, Wöhlbrand L, Rabus R. Differential proteomic analysis of the metabolic network of the marine sulfate-reducer Desulfobacterium autotrophicum HRM2. Proteomics 2017; 16:2878-2893. [PMID: 27701823 DOI: 10.1002/pmic.201600041] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 08/24/2016] [Accepted: 09/30/2016] [Indexed: 01/30/2023]
Abstract
The marine sulfate-reducing bacterium Desulfobacterium autotrophicum HRM2 belongs to the deltaproteobacterial family Desulfobacteraceae and stands out for its capacity of facultative chemolithoautotrophic growth (next to heterotrophy). Here, proteomics-driven metabolic reconstruction was based on a combination of 2D-DIGE, shotgun proteomics, and analysis of the membrane protein enriched fraction applied to eight different substrate adaptation conditions (seven aliphatic compounds plus H2 /CO2 ). In total, 1344 different proteins were identified (∼27% of the 4947 genome-predicted), from which a complex metabolic network was reconstructed consisting of 136 proteins (124 detected; ∼91%). Peripheral degradation routes for organic substrates feed directly or via the methylmalonyl-CoA pathway into the Wood-Ljungdahl pathway (WLP) for terminal oxidation to CO2 . Chemolithoautotrophic growth apparently involves the periplasmic [Ni/Fe/Se]-containing hydrogenase HysAB (H2 oxidation), the reductively operating WLP (CO2 fixation), and classical gluconeogenesis. Diverse soluble proteins (e.g., Hdr, Etf) probably establish a fine balanced cytoplasmic electron transfer network connecting individual catabolic reactions with the membrane menaquinone pool. In addition, multiple membrane protein complexes (Nqr, Qmo, Qrc, Rnf1, Rnf2, and Tmc) provide ample routes for interacting with the reducing equivalent pool and delivering electrons to dissimilatory sulfate reduction (both localized in the cytoplasm). Overall, this study contributes to the molecular understanding of the habitat-relevant Desulfobacteraceae.
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Affiliation(s)
- Marvin Dörries
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Lars Wöhlbrand
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Ralf Rabus
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg, Oldenburg, Germany.,Department Microbiology, Max Planck Institute for Marine Microbiology, Bremen, Germany
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115
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Barton LL, Ritz NL, Fauque GD, Lin HC. Sulfur Cycling and the Intestinal Microbiome. Dig Dis Sci 2017; 62:2241-2257. [PMID: 28766244 DOI: 10.1007/s10620-017-4689-5] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 07/19/2017] [Indexed: 02/08/2023]
Abstract
In this review, we focus on the activities transpiring in the anaerobic segment of the sulfur cycle occurring in the gut environment where hydrogen sulfide is produced. While sulfate-reducing bacteria are considered as the principal agents for hydrogen sulfide production, the enzymatic desulfhydration of cysteine by heterotrophic bacteria also contributes to production of hydrogen sulfide. For sulfate-reducing bacteria respiration, molecular hydrogen and lactate are suitable as electron donors while sulfate functions as the terminal electron acceptor. Dietary components provide fiber and macromolecules that are degraded by bacterial enzymes to monomers, and these are fermented by intestinal bacteria with the production to molecular hydrogen which promotes the metabolic dominance by sulfate-reducing bacteria. Sulfate is also required by the sulfate-reducing bacteria, and this can be supplied by sulfate- and sulfonate-containing compounds that are hydrolyzed by intestinal bacterial with the release of sulfate. While hydrogen sulfide in the intestinal biosystem may be beneficial to bacteria by increasing resistance to antibiotics, and protecting them from reactive oxygen species, hydrogen sulfide at elevated concentrations may become toxic to the host.
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Affiliation(s)
- Larry L Barton
- Department of Biology, MSCO3 2020, University of New Mexico, Albuquerque, NM, 87131, USA.
| | - Nathaniel L Ritz
- New Mexico VA Health Care System, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Guy D Fauque
- CNRS, IRD, Mediterranean Institute of Oceanography (MIO) UM 110, Aix-Marseille Université, Université de Toulon, Campus de Luminy, Case 901, 13288, Marseille Cedex 09, France
| | - Henry C Lin
- New Mexico VA Health Care System, University of New Mexico, Albuquerque, NM, 87131, USA
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116
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Gilmore SP, Henske JK, Sexton JA, Solomon KV, Seppälä S, Yoo JI, Huyett LM, Pressman A, Cogan JZ, Kivenson V, Peng X, Tan Y, Valentine DL, O'Malley MA. Genomic analysis of methanogenic archaea reveals a shift towards energy conservation. BMC Genomics 2017; 18:639. [PMID: 28826405 PMCID: PMC5563889 DOI: 10.1186/s12864-017-4036-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 08/08/2017] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND The metabolism of archaeal methanogens drives methane release into the environment and is critical to understanding global carbon cycling. Methanogenesis operates at a very low reducing potential compared to other forms of respiration and is therefore critical to many anaerobic environments. Harnessing or altering methanogen metabolism has the potential to mitigate global warming and even be utilized for energy applications. RESULTS Here, we report draft genome sequences for the isolated methanogens Methanobacterium bryantii, Methanosarcina spelaei, Methanosphaera cuniculi, and Methanocorpusculum parvum. These anaerobic, methane-producing archaea represent a diverse set of isolates, capable of methylotrophic, acetoclastic, and hydrogenotrophic methanogenesis. Assembly and analysis of the genomes allowed for simple and rapid reconstruction of metabolism in the four methanogens. Comparison of the distribution of Clusters of Orthologous Groups (COG) proteins to a sample of genomes from the RefSeq database revealed a trend towards energy conservation in genome composition of all methanogens sequenced. Further analysis of the predicted membrane proteins and transporters distinguished differing energy conservation methods utilized during methanogenesis, such as chemiosmotic coupling in Msar. spelaei and electron bifurcation linked to chemiosmotic coupling in Mbac. bryantii and Msph. cuniculi. CONCLUSIONS Methanogens occupy a unique ecological niche, acting as the terminal electron acceptors in anaerobic environments, and their genomes display a significant shift towards energy conservation. The genome-enabled reconstructed metabolisms reported here have significance to diverse anaerobic communities and have led to proposed substrate utilization not previously reported in isolation, such as formate and methanol metabolism in Mbac. bryantii and CO2 metabolism in Msph. cuniculi. The newly proposed substrates establish an important foundation with which to decipher how methanogens behave in native communities, as CO2 and formate are common electron carriers in microbial communities.
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Affiliation(s)
- Sean P Gilmore
- Department of Chemical Engineering, University of California, Santa Barbara, California, USA
| | - John K Henske
- Department of Chemical Engineering, University of California, Santa Barbara, California, USA
| | - Jessica A Sexton
- Department of Chemical Engineering, University of California, Santa Barbara, California, USA
| | - Kevin V Solomon
- Department of Chemical Engineering, University of California, Santa Barbara, California, USA.,Present Address: Agricultural & Biological Engineering, Purdue University, West Lafayette, Indiana, USA
| | - Susanna Seppälä
- Department of Chemical Engineering, University of California, Santa Barbara, California, USA.,Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Hørsholm, Denmark
| | - Justin I Yoo
- Department of Chemical Engineering, University of California, Santa Barbara, California, USA
| | - Lauren M Huyett
- Department of Chemical Engineering, University of California, Santa Barbara, California, USA
| | - Abe Pressman
- Department of Chemical Engineering, University of California, Santa Barbara, California, USA
| | - James Z Cogan
- Biology Program, College of Creative Studies, University of California, Santa Barbara, California, USA
| | - Veronika Kivenson
- Department of Earth Science and Marine Science Institute, University of California, Santa Barbara, California, USA
| | - Xuefeng Peng
- Department of Chemical Engineering, University of California, Santa Barbara, California, USA.,Department of Earth Science and Marine Science Institute, University of California, Santa Barbara, California, USA
| | - YerPeng Tan
- California NanoScience Institute, University of California, Santa Barbara, California, USA
| | - David L Valentine
- Department of Earth Science and Marine Science Institute, University of California, Santa Barbara, California, USA
| | - Michelle A O'Malley
- Department of Chemical Engineering, University of California, Santa Barbara, California, USA.
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117
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Wagner T, Koch J, Ermler U, Shima S. Methanogenic heterodisulfide reductase (HdrABC-MvhAGD) uses two noncubane [4Fe-4S] clusters for reduction. Science 2017; 357:699-703. [DOI: 10.1126/science.aan0425] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Accepted: 07/25/2017] [Indexed: 12/15/2022]
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118
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Qin QS, Feng DS, Liu PF, He Q, Li X, Liu AM, Zhang H, Hu GQ, Cheng L. Metagenomic Characterization of Candidatus Smithella cisternae Strain M82_1, a Syntrophic Alkane-Degrading Bacteria, Enriched from the Shengli Oil Field. Microbes Environ 2017; 32:234-243. [PMID: 28781346 PMCID: PMC5606693 DOI: 10.1264/jsme2.me17022] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The methanogenic degradation of hydrocarbons plays an important role in hydrocarbon-contaminated environments in the absence of an external electron acceptor. Members of Syntrophaceae sublineages were previously reported to be responsible for syntrophic alkane degradation. However, limited information is currently available on their physiological capabilities in nature because it is very challenging to cultivate these as-yet uncultured microbes. We herein performed metagenomic sequencing of the methanogenic hexadecane-degrading culture M82 and recovered a nearly complete genome (2.75 Mb, estimated completeness ≥97%) belonging to Syntrophaceae sublineage II. The assembly genome was tentatively named “Candidatus Smithella cisternae strain M82_1”. Genes encoding alkylsuccinate synthase for alkane activation were identified, suggesting that this organism is capable of oxidizing alkanes through fumarate addition. This capability was further supported by the detection of methyl pentadecyl succinic acid and methyl tetradecyl succinic acid in cultures amended with hexadecane and pentadecane, respectively. Genes encoding enzymes for the β-oxidation of long-chain fatty acids and butyrate were also identified. The electron transfer flavoprotein/DUF224 complex is presumed to link electron flow from acyl-CoA dehydrogenase to a membrane hydrogenase or formate dehydrogenase. Although no indications of Rnf complexes were detected, genes encoding electron-confurcating hydrogenase and formate dehydrogenase were proposed to couple the thermodynamically favorable oxidation of ferredoxin to generate H2 and formate from NADH. Strain M82_1 synthesized ATP from acetyl-CoA by substrate-level phosphorylation or F1F0-ATP synthases. These results provide an insight into the potential metabolic traits and ecophysiological roles of the syntrophic alkane degrader Syntrophaceae.
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Affiliation(s)
- Qian-Shan Qin
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture
| | | | - Peng-Fei Liu
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture
| | - Qiao He
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture
| | - Xia Li
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture
| | | | - Hui Zhang
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture
| | - Guo-Quan Hu
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture
| | - Lei Cheng
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture
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119
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Methane-Fueled Syntrophy through Extracellular Electron Transfer: Uncovering the Genomic Traits Conserved within Diverse Bacterial Partners of Anaerobic Methanotrophic Archaea. mBio 2017; 8:mBio.00530-17. [PMID: 28765215 PMCID: PMC5539420 DOI: 10.1128/mbio.00530-17] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The anaerobic oxidation of methane by anaerobic methanotrophic (ANME) archaea in syntrophic partnership with deltaproteobacterial sulfate-reducing bacteria (SRB) is the primary mechanism for methane removal in ocean sediments. The mechanism of their syntrophy has been the subject of much research as traditional intermediate compounds, such as hydrogen and formate, failed to decouple the partners. Recent findings have indicated the potential for extracellular electron transfer from ANME archaea to SRB, though it is unclear how extracellular electrons are integrated into the metabolism of the SRB partner. We used metagenomics to reconstruct eight genomes from the globally distributed SEEP-SRB1 clade of ANME partner bacteria to determine what genomic features are required for syntrophy. The SEEP-SRB1 genomes contain large multiheme cytochromes that were not found in previously described free-living SRB and also lack periplasmic hydrogenases that may prevent an independent lifestyle without an extracellular source of electrons from ANME archaea. Metaproteomics revealed the expression of these cytochromes at in situ methane seep sediments from three sites along the Pacific coast of the United States. Phylogenetic analysis showed that these cytochromes appear to have been horizontally transferred from metal-respiring members of the Deltaproteobacteria such as Geobacter and may allow these syntrophic SRB to accept extracellular electrons in place of other chemical/organic electron donors. Some archaea, known as anaerobic methanotrophs, are capable of converting methane into carbon dioxide when they are growing syntopically with sulfate-reducing bacteria. This partnership is the primary mechanism for methane removal in ocean sediments; however, there is still much to learn about how this syntrophy works. Previous studies have failed to identify the metabolic intermediate, such as hydrogen or formate, that is passed between partners. However, recent analysis of methanotrophic archaea has suggested that the syntrophy is formed through direct electron transfer. In this research, we analyzed the genomes of multiple partner bacteria and showed that they also contain the genes necessary to perform extracellular electron transfer, which are absent in related bacteria that do not form syntrophic partnerships with anaerobic methanotrophs. This genomic evidence shows a possible mechanism for direct electron transfer from methanotrophic archaea into the metabolism of the partner bacteria.
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120
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Mourato C, Martins M, da Silva SM, Pereira IAC. A continuous system for biocatalytic hydrogenation of CO 2 to formate. BIORESOURCE TECHNOLOGY 2017; 235:149-156. [PMID: 28365342 DOI: 10.1016/j.biortech.2017.03.091] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/15/2017] [Accepted: 03/16/2017] [Indexed: 05/20/2023]
Abstract
In this work a novel bioprocess for hydrogenation of CO2 to formate was developed, using whole cell catalysis by a sulfate-reducing bacterium. Three Desulfovibrio species were tested (D. vulgaris Hildenborough, D. alaskensis G20, and D. desulfuricans ATCC 27774), of which D. desulfuricans showed the highest activity, producing 12mM of formate in batch, with a production rate of 0.09mMh-1. Gene expression analysis indicated that among the three formate dehydrogenases and five hydrogenases, the cytoplasmic FdhAB and the periplasmic [FeFe] HydAB are the main enzymes expressed in D. desulfuricans in these conditions. The new bioprocess for continuous formate production by D. desulfuricans had a maximum specific formate production rate of 14mMgdcw-1h-1, and more than 45mM of formate were obtained with a production rate of 0.40mMh-1. This is the first report of a continuous process for biocatalytic formate production.
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Affiliation(s)
- Cláudia Mourato
- Instituto de Tecnologia Química e Biológica António Xavier/Universidade Nova de Lisboa (ITQB NOVA), Av. da Republica-EAN, 2780-157 Oeiras, Portugal
| | - Mónica Martins
- Instituto de Tecnologia Química e Biológica António Xavier/Universidade Nova de Lisboa (ITQB NOVA), Av. da Republica-EAN, 2780-157 Oeiras, Portugal
| | - Sofia M da Silva
- Instituto de Tecnologia Química e Biológica António Xavier/Universidade Nova de Lisboa (ITQB NOVA), Av. da Republica-EAN, 2780-157 Oeiras, Portugal
| | - Inês A C Pereira
- Instituto de Tecnologia Química e Biológica António Xavier/Universidade Nova de Lisboa (ITQB NOVA), Av. da Republica-EAN, 2780-157 Oeiras, Portugal.
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121
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Baba R, Morita M, Asakawa S, Watanabe T. Transcription of [FeFe]-Hydrogenase Genes during H 2 Production in Clostridium and Desulfovibrio spp. Isolated from a Paddy Field Soil. Microbes Environ 2017; 32:125-132. [PMID: 28502969 PMCID: PMC5478535 DOI: 10.1264/jsme2.me16171] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Changes in the relative abundances of the transcripts of hydA gene paralogs for [FeFe]-hydrogenase in Clostridium sp. strain H2 and Desulfovibrio sp. strain A1 isolated from paddy field soil were analyzed during H2 production. Strains H2 and A1 had at least five and two phylogenetically different hydA genes, respectively. The relative abundances of their hydA transcripts differed among the paralogs and H2 production activity changed in a manner that depended on the growth phase and conditions. Increases or decreases in the relative abundances of the transcripts of two out of five hydA genes in strain H2 correlated with changes in H2 production rates, whereas those of the others remained unchanged or decreased. In strain A1, the relative abundances of the transcripts of two hydA genes differed between monoculture, sulfate-reducing, and syntrophic, methanogenic conditions. The relative abundance of the transcripts of one hydA gene, predicted to encode a cytosolic [FeFe]-hydrogenase, was higher under syntrophic, methanogenic conditions than sulfate-reducing conditions, while that of the transcripts of the other hydA gene decreased with time under both conditions. This study showed that the transcription of the hydA gene during growth with active H2 production was differently regulated among the paralogs in H2 producers isolated from paddy field soil.
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Affiliation(s)
- Ryuko Baba
- Laboratory of Soil Biology and Chemistry, Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University
| | - Mayumi Morita
- Laboratory of Soil Biology and Chemistry, School of Agricultural Sciences, Nagoya University
| | - Susumu Asakawa
- Laboratory of Soil Biology and Chemistry, Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University
| | - Takeshi Watanabe
- Laboratory of Soil Biology and Chemistry, Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University
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122
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Carlson HK, Mullan MR, Mosqueda LA, Chen S, Arkin MR, Coates JD. High-Throughput Screening To Identify Potent and Specific Inhibitors of Microbial Sulfate Reduction. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:7278-7285. [PMID: 28492331 DOI: 10.1021/acs.est.7b00686] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The selective perturbation of complex microbial ecosystems to predictably influence outcomes in engineered and industrial environments remains a grand challenge for geomicrobiology. In some industrial ecosystems, such as oil reservoirs, sulfate reducing microorganisms (SRM) produce hydrogen sulfide which is toxic, explosive, and corrosive. Despite the economic cost of sulfidogenesis, there has been minimal exploration of the chemical space of possible inhibitory compounds, and very little work has quantitatively assessed the selectivity of putative souring treatments. We have developed a high-throughput screening strategy to identify potent and selective inhibitors of SRM, quantitatively ranked the selectivity and potency of hundreds of compounds and identified previously unrecognized SRM selective inhibitors and synergistic interactions between inhibitors. Zinc pyrithione is the most potent inhibitor of sulfidogenesis that we identified, and is several orders of magnitude more potent than commonly used industrial biocides. Both zinc and copper pyrithione are also moderately selective against SRM. The high-throughput (HT) approach we present can be readily adapted to target SRM in diverse environments and similar strategies could be used to quantify the potency and selectivity of inhibitors of a variety of microbial metabolisms. Our findings and approach are relevant to efforts to engineer environmental ecosystems and also to understand the role of natural gradients in shaping microbial niche space.
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Affiliation(s)
- Hans K Carlson
- Energy Biosciences Institute, University of California, Berkeley , Berkeley, California 94720, United States
- Physical Biosciences Division, Lawrence Berkeley National Lab , Berkeley, California 94720, United States
| | - Mark R Mullan
- Energy Biosciences Institute, University of California, Berkeley , Berkeley, California 94720, United States
| | - Lorraine A Mosqueda
- Energy Biosciences Institute, University of California, Berkeley , Berkeley, California 94720, United States
| | - Steven Chen
- Small Molecule Discovery Center, University of California, San Francisco , San Francisco, California 94143, United States
| | - Michelle R Arkin
- Small Molecule Discovery Center, University of California, San Francisco , San Francisco, California 94143, United States
| | - John D Coates
- Energy Biosciences Institute, University of California, Berkeley , Berkeley, California 94720, United States
- Earth Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
- Department of Plant and Microbial Biology, University of California, Berkeley , Berkeley, California 94720, United States
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123
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Clark IC, Abate AR. Finding a helix in a haystack: nucleic acid cytometry with droplet microfluidics. LAB ON A CHIP 2017; 17:2032-2045. [PMID: 28540956 PMCID: PMC6005652 DOI: 10.1039/c7lc00241f] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Nucleic acids encode the information of life, programming cellular functions and dictating many biological outcomes. Differentiating between cells based on their nucleic acid programs is, thus, a powerful way to unravel the genetic bases of many phenotypes. This is especially important considering that most cells exist in heterogeneous populations, requiring them to be isolated before they can be studied. Existing flow cytometry techniques, however, are unable to reliably recover specific cells based on nucleic acid content. Nucleic acid cytometry is a new field built on droplet microfluidics that allows robust identification, sorting, and sequencing of cells based on specific nucleic acid biomarkers. This review highlights applications that immediately benefit from the approach, biological questions that can be addressed for the first time with it, and considerations for building successful workflows.
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Affiliation(s)
- Iain C Clark
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA.
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124
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Rasigraf O, Schmitt J, Jetten MSM, Lüke C. Metagenomic potential for and diversity of N-cycle driving microorganisms in the Bothnian Sea sediment. Microbiologyopen 2017; 6. [PMID: 28544522 PMCID: PMC5552932 DOI: 10.1002/mbo3.475] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Revised: 02/13/2017] [Accepted: 02/22/2017] [Indexed: 11/10/2022] Open
Abstract
The biological nitrogen cycle is driven by a plethora of reactions transforming nitrogen compounds between various redox states. Here, we investigated the metagenomic potential for nitrogen cycle of the in situ microbial community in an oligotrophic, brackish environment of the Bothnian Sea sediment. Total DNA from three sediment depths was isolated and sequenced. The characterization of the total community was performed based on 16S rRNA gene inventory using SILVA database as reference. The diversity of diagnostic functional genes coding for nitrate reductases (napA;narG), nitrite:nitrate oxidoreductase (nxrA), nitrite reductases (nirK;nirS;nrfA), nitric oxide reductase (nor), nitrous oxide reductase (nosZ), hydrazine synthase (hzsA), ammonia monooxygenase (amoA), hydroxylamine oxidoreductase (hao), and nitrogenase (nifH) was analyzed by blastx against curated reference databases. In addition, Polymerase chain reaction (PCR)‐based amplification was performed on the hzsA gene of anammox bacteria. Our results reveal high genomic potential for full denitrification to N2, but minor importance of anaerobic ammonium oxidation and dissimilatory nitrite reduction to ammonium. Genomic potential for aerobic ammonia oxidation was dominated by Thaumarchaeota. A higher diversity of anammox bacteria was detected in metagenomes than with PCR‐based technique. The results reveal the importance of various N‐cycle driving processes and highlight the advantage of metagenomics in detection of novel microbial key players.
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Affiliation(s)
- Olivia Rasigraf
- Department of Microbiology, IWWR, Radboud University Nijmegen, Nijmegen, Netherlands
| | - Julia Schmitt
- DVGW-Forschungsstelle TUHH, Hamburg University of Technology, Hamburg, Germany
| | - Mike S M Jetten
- Department of Microbiology, IWWR, Radboud University Nijmegen, Nijmegen, Netherlands.,Department of Biotechnology, Delft University of Technology, Delft, Netherlands.,Soehngen Institute of Anaerobic Microbiology, Nijmegen, Netherlands
| | - Claudia Lüke
- Department of Microbiology, IWWR, Radboud University Nijmegen, Nijmegen, Netherlands
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125
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Kryachko Y, Hemmingsen SM. The Role of Localized Acidity Generation in Microbially Influenced Corrosion. Curr Microbiol 2017; 74:870-876. [PMID: 28444419 DOI: 10.1007/s00284-017-1254-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/13/2017] [Indexed: 10/19/2022]
Abstract
Microbially influenced corrosion is of great industrial concern. Microbial coupling of metal oxidation to sulfate-, nitrate-, nitrite-, or CO2-reduction is proton-mediated, and some sulfate-reducing prokaryotes are capable of regulating extracellular pH. The analysis of the corrosive processes catalyzed by nitrate reducing bacteria and methanogenic archaea indicates that these microorganisms may be capable of regulating extracellular pH as well. It is proposed that nutrient limitation at metal-biofilm interfaces may induce activation of enzymatic proton-producing/proton-secreting functions in respiratory and methanogenic microorganisms to make them capable of using Fe0 as the electron donor. This can be further verified through experiments involving measurements of ion and gas concentrations at metal-biofilm interfaces, microscopy, and transcriptomics analyses.
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Affiliation(s)
- Yuriy Kryachko
- National Research Council Canada, 110 Gymnasium Place, Saskatoon, SK, S7N 0W9, Canada.
| | - Sean M Hemmingsen
- National Research Council Canada, 110 Gymnasium Place, Saskatoon, SK, S7N 0W9, Canada
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126
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Kurth D, Amadio A, Ordoñez OF, Albarracín VH, Gärtner W, Farías ME. Arsenic metabolism in high altitude modern stromatolites revealed by metagenomic analysis. Sci Rep 2017; 7:1024. [PMID: 28432307 PMCID: PMC5430908 DOI: 10.1038/s41598-017-00896-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 03/16/2017] [Indexed: 11/09/2022] Open
Abstract
Modern stromatolites thrive only in selected locations in the world. Socompa Lake, located in the Andean plateau at 3570 masl, is one of the numerous extreme Andean microbial ecosystems described over recent years. Extreme environmental conditions include hypersalinity, high UV incidence, and high arsenic content, among others. After Socompa's stromatolite microbial communities were analysed by metagenomic DNA sequencing, taxonomic classification showed dominance of Proteobacteria, Bacteroidetes and Firmicutes, and a remarkably high number of unclassified sequences. A functional analysis indicated that carbon fixation might occur not only by the Calvin-Benson cycle, but also through alternative pathways such as the reverse TCA cycle, and the reductive acetyl-CoA pathway. Deltaproteobacteria were involved both in sulfate reduction and nitrogen fixation. Significant differences were found when comparing the Socompa stromatolite metagenome to the Shark Bay (Australia) smooth mat metagenome: namely, those involving stress related processes, particularly, arsenic resistance. An in-depth analysis revealed a surprisingly diverse metabolism comprising all known types of As resistance and energy generating pathways. While the ars operon was the main mechanism, an important abundance of arsM genes was observed in selected phyla. The data resulting from this work will prove a cornerstone for further studies on this rare microbial community.
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Affiliation(s)
- Daniel Kurth
- Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CCT Tucumán, CONICET, San Miguel de Tucumán, Argentina
| | - Ariel Amadio
- E.E.A. Rafaela, Instituto Nacional de Tecnología Agropecuaria (INTA), CCT Santa Fe, CONICET, Rafaela, Argentina
| | - Omar F Ordoñez
- Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CCT Tucumán, CONICET, San Miguel de Tucumán, Argentina
| | - Virginia H Albarracín
- Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CCT Tucumán, CONICET, San Miguel de Tucumán, Argentina
- Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, San Miguel de Tucumán, Argentina
| | - Wolfgang Gärtner
- Max-Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr, Germany
| | - María E Farías
- Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CCT Tucumán, CONICET, San Miguel de Tucumán, Argentina.
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127
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Ang WK, Mahbob M, Dhouib R, Kappler U. Sulfur compound oxidation and carbon co-assimilation in the haloalkaliphilic sulfur oxidizers Thioalkalivibrio versutus and Thioalkalimicrobium aerophilum. Res Microbiol 2017; 168:255-265. [DOI: 10.1016/j.resmic.2016.12.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 12/09/2016] [Accepted: 12/20/2016] [Indexed: 10/20/2022]
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128
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Zhang M, Liu X, Li Y, Wang G, Wang Z, Wen J. Microbial community and metabolic pathway succession driven by changed nutrient inputs in tailings: effects of different nutrients on tailing remediation. Sci Rep 2017; 7:474. [PMID: 28352108 PMCID: PMC5428726 DOI: 10.1038/s41598-017-00580-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 03/06/2017] [Indexed: 11/24/2022] Open
Abstract
To solve the competition problem of acidophilic bacteria and sulfate-reducing bacteria in the practical application of mine tailing bioremediation, research into the mechanisms of using different nutrients to adjust the microbial community was conducted. Competition experiments involving acidophilic bacteria and sulfate-reducing bacteria were performed by supplementing the media with yeast extract, tryptone, lactate, and glucose. The physiochemical properties were determined, and the microbial community structure and biomass were investigated using MiSeq sequencing and qRT-PCR, respectively. Four nutrients had different remediation mechanisms and yielded different remediation effects. Yeast extract and tryptone (more than 1.6 g/L) promoted sulfate-reducing bacteria and inhibited acidophilic bacteria. Lactate inhibited both sulfate-reducing and acidophilic bacteria. Glucose promoted acidophilic bacteria more than sulfate-reducing bacteria. Yeast extract was the best choice for adjusting the microbial community and bioremediation, followed by tryptone. Lactate kept the physiochemical properties stable or made slight improvements; however, glucose was not suitable for mine tailing remediation. Different nutrients had significant effects on the abundance of the second enzyme of the sulfate-reducing pathway (p < 0.05), which is the rate-limiting step of sulfate-reducing pathways. Nutrients changed the remediation effects effectively by adjusting the microbial community and the abundance of the sulfate-reducing rate-limiting enzyme.
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Affiliation(s)
- Mingjiang Zhang
- National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Nonferrous Metals, No. 2 Xinjiekouwai Street, Beijing, 100088, China
| | - Xingyu Liu
- National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Nonferrous Metals, No. 2 Xinjiekouwai Street, Beijing, 100088, China.
| | - Yibin Li
- National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Nonferrous Metals, No. 2 Xinjiekouwai Street, Beijing, 100088, China
| | - Guangyuan Wang
- National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Nonferrous Metals, No. 2 Xinjiekouwai Street, Beijing, 100088, China
| | - Zining Wang
- National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Nonferrous Metals, No. 2 Xinjiekouwai Street, Beijing, 100088, China
| | - Jiankang Wen
- National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Nonferrous Metals, No. 2 Xinjiekouwai Street, Beijing, 100088, China
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129
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Twing KI, Brazelton WJ, Kubo MDY, Hyer AJ, Cardace D, Hoehler TM, McCollom TM, Schrenk MO. Serpentinization-Influenced Groundwater Harbors Extremely Low Diversity Microbial Communities Adapted to High pH. Front Microbiol 2017; 8:308. [PMID: 28298908 PMCID: PMC5331062 DOI: 10.3389/fmicb.2017.00308] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 02/14/2017] [Indexed: 11/25/2022] Open
Abstract
Serpentinization is a widespread geochemical process associated with aqueous alteration of ultramafic rocks that produces abundant reductants (H2 and CH4) for life to exploit, but also potentially challenging conditions, including high pH, limited availability of terminal electron acceptors, and low concentrations of inorganic carbon. As a consequence, past studies of serpentinites have reported low cellular abundances and limited microbial diversity. Establishment of the Coast Range Ophiolite Microbial Observatory (California, U.S.A.) allowed a comparison of microbial communities and physicochemical parameters directly within serpentinization-influenced subsurface aquifers. Samples collected from seven wells were subjected to a range of analyses, including solute and gas chemistry, microbial diversity by 16S rRNA gene sequencing, and metabolic potential by shotgun metagenomics, in an attempt to elucidate what factors drive microbial activities in serpentinite habitats. This study describes the first comprehensive interdisciplinary analysis of microbial communities in hyperalkaline groundwater directly accessed by boreholes into serpentinite rocks. Several environmental factors, including pH, methane, and carbon monoxide, were strongly associated with the predominant subsurface microbial communities. A single operational taxonomic unit (OTU) of Betaproteobacteria and a few OTUs of Clostridia were the almost exclusive inhabitants of fluids exhibiting the most serpentinized character. Metagenomes from these extreme samples contained abundant sequences encoding proteins associated with hydrogen metabolism, carbon monoxide oxidation, carbon fixation, and acetogenesis. Metabolic pathways encoded by Clostridia and Betaproteobacteria, in particular, are likely to play important roles in the ecosystems of serpentinizing groundwater. These data provide a basis for further biogeochemical studies of key processes in serpentinite subsurface environments.
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Affiliation(s)
- Katrina I Twing
- Department of Microbiology and Molecular Genetics, Michigan State University, East LansingMI, USA; Department of Biology, University of Utah, Salt Lake CityUT, USA
| | | | | | - Alex J Hyer
- Department of Biology, University of Utah, Salt Lake City UT, USA
| | - Dawn Cardace
- Department of Geosciences, University of Rhode Island, Kingston RI, USA
| | - Tori M Hoehler
- Exobiology Branch, NASA Ames Research Center, Moffett Field CA, USA
| | - Tom M McCollom
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder CO, USA
| | - Matthew O Schrenk
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing MI, USA
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130
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Slobodkina GB, Mardanov AV, Ravin NV, Frolova AA, Chernyh NA, Bonch-Osmolovskaya EA, Slobodkin AI. Respiratory Ammonification of Nitrate Coupled to Anaerobic Oxidation of Elemental Sulfur in Deep-Sea Autotrophic Thermophilic Bacteria. Front Microbiol 2017; 8:87. [PMID: 28194142 PMCID: PMC5276818 DOI: 10.3389/fmicb.2017.00087] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 01/12/2017] [Indexed: 02/05/2023] Open
Abstract
Respiratory ammonification of nitrate is the microbial process that determines the retention of nitrogen in an ecosystem. To date, sulfur-dependent dissimilatory nitrate reduction to ammonium has been demonstrated only with sulfide as an electron donor. We detected a novel pathway that couples the sulfur and nitrogen cycles. Thermophilic anaerobic bacteria Thermosulfurimonas dismutans and Dissulfuribacter thermophilus, isolated from deep-sea hydrothermal vents, grew autotrophically with elemental sulfur as an electron donor and nitrate as an electron acceptor producing sulfate and ammonium. The genomes of both bacteria contain a gene cluster that encodes a putative nitrate ammonification enzyme system. Nitrate reduction occurs via a Nap-type complex. The reduction of produced nitrite to ammonium does not proceed via the canonical Nrf system because nitrite reductase NrfA is absent in the genomes of both microorganisms. The genome of D. thermophilus encodes a complete sulfate reduction pathway, while the Sox sulfur oxidation system is missing, as shown previously for T. dismutans. Thus, in high-temperature environments, nitrate ammonification with elemental sulfur may represent an unrecognized route of primary biomass production. Moreover, the anaerobic oxidation of sulfur compounds coupled to growth has not previously been demonstrated for the members of Thermodesulfobacteria or Deltaproteobacteria, which were considered exclusively as participants of the reductive branch of the sulfur cycle.
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Affiliation(s)
- Galina B Slobodkina
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
| | - Andrey V Mardanov
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
| | - Nikolai V Ravin
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
| | - Anastasia A Frolova
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
| | - Nikolay A Chernyh
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
| | - Elizaveta A Bonch-Osmolovskaya
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
| | - Alexander I Slobodkin
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
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131
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Martins M, Mourato C, Sanches S, Noronha JP, Crespo MTB, Pereira IAC. Biogenic platinum and palladium nanoparticles as new catalysts for the removal of pharmaceutical compounds. WATER RESEARCH 2017; 108:160-168. [PMID: 27817891 DOI: 10.1016/j.watres.2016.10.071] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 10/25/2016] [Accepted: 10/27/2016] [Indexed: 06/06/2023]
Abstract
Pharmaceutical products (PhP) are one of the most alarming emergent pollutants in the environment. Therefore, it is of extreme importance to investigate efficient PhP removal processes. Biologic synthesis of platinum nanoparticles (Bio-Pt) has been reported, but their catalytic activity was never investigated. In this work, we explored the potential of cell-supported platinum (Bio-Pt) and palladium (Bio-Pd) nanoparticles synthesized with Desulfovibrio vulgaris as biocatalysts for removal of four PhP: ciprofloxacin, sulfamethoxazole, ibuprofen and 17β-estradiol. The catalytic activity of the biological nanoparticles was compared with the PhP removal efficiency of D. vulgaris whole-cells. In contrast with Bio-Pd, Bio-Pt has a high catalytic activity in PhP removal, with 94, 85 and 70% removal of 17β-estradiol, sulfamethoxazole and ciprofloxacin, respectively. In addition, the estrogenic activity of 17β-estradiol was strongly reduced after the reaction with Bio-Pt, showing that this biocatalyst produces less toxic effluents. Bio-Pt or Bio-Pd did not act on ibuprofen, but this could be completely removed by D. vulgaris whole-cells, demonstrating that sulfate-reducing bacteria are among the microorganisms capable of biotransformation of ibuprofen in anaerobic environments. This study demonstrates for the first time that Bio-Pt has a high catalytic activity, and is a promising catalyst to be used in water treatment processes for the removal of antibiotics and endocrine disrupting compounds, the most problematic PhP.
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Affiliation(s)
- Mónica Martins
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier/ Universidade Nova de Lisboa, Av. da Republica-EAN, 2780-157 Oeiras, Portugal.
| | - Cláudia Mourato
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier/ Universidade Nova de Lisboa, Av. da Republica-EAN, 2780-157 Oeiras, Portugal
| | - Sandra Sanches
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780-901 Oeiras, Portugal
| | - João Paulo Noronha
- LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - M T Barreto Crespo
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier/ Universidade Nova de Lisboa, Av. da Republica-EAN, 2780-157 Oeiras, Portugal; iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780-901 Oeiras, Portugal
| | - Inês A C Pereira
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier/ Universidade Nova de Lisboa, Av. da Republica-EAN, 2780-157 Oeiras, Portugal.
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132
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Frank YA, Kadnikov VV, Lukina AP, Banks D, Beletsky AV, Mardanov AV, Sen'kina EI, Avakyan MR, Karnachuk OV, Ravin NV. Characterization and Genome Analysis of the First Facultatively Alkaliphilic Thermodesulfovibrio Isolated from the Deep Terrestrial Subsurface. Front Microbiol 2016; 7:2000. [PMID: 28066337 PMCID: PMC5165239 DOI: 10.3389/fmicb.2016.02000] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 11/29/2016] [Indexed: 11/16/2022] Open
Abstract
Members of the genus Thermodesulfovibrio belong to the Nitrospirae phylum and all isolates characterized to date are neutrophiles. They have been isolated from terrestrial hot springs and thermophilic methanogenic anaerobic sludges. Their molecular signatures have, however, also been detected in deep subsurface. The purpose of this study was to characterize and analyze the genome of a newly isolated, facultatively alkaliphilic Thermodesulfovibrio from a 2 km deep aquifer system in Western Siberia, Russia. The new isolate, designated N1, grows optimally at pH 8.5 and at 65°C. It is able to reduce sulfate, thiosulfate or sulfite with a limited range of electron donors, such as formate, pyruvate, and lactate. Analysis of the 1.93 Mb draft genome of strain N1 revealed that it contains a set of genes for dissimilatory sulfate reduction, including sulfate adenyltransferase, adenosine-5′-phosphosulfate reductase AprAB, membrane-bound electron transfer complex QmoABC, dissimilatory sulfite reductase DsrABC, and sulfite reductase-associated electron transfer complex DsrMKJOP. Hydrogen turnover is enabled by soluble cytoplasmic, membrane-linked, and soluble periplasmic hydrogenases. The use of thiosulfate as an electron acceptor is enabled by a membrane-linked molybdopterin oxidoreductase. The N1 requirement for organic carbon sources corresponds to the lack of the autotrophic C1-fixation pathways. Comparative analysis of the genomes of Thermodesulfovibrio (T. yellowstonii, T. islandicus, T. àggregans, T. thiophilus, and strain N1) revealed a low overall genetic diversity and several adaptive traits. Consistent with an alkaliphilic lifestyle, a multisubunit Na+/H+ antiporter of the Mnh family is encoded in the Thermodesulfovibrio strain N1 genome. Nitrogenase genes were found in T. yellowstonii, T. aggregans, and T. islandicus, nitrate reductase in T. islandicus, and cellulose synthetase in T. aggregans and strain N1. Overall, our results provide genomic insights into metabolism of the Thermodesulfovibrio lineage in microbial communities of the deep subsurface biosphere.
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Affiliation(s)
- Yulia A Frank
- Laboratory of Biochemistry and Molecular Biology, Tomsk State University Tomsk, Russia
| | - Vitaly V Kadnikov
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
| | - Anastasia P Lukina
- Laboratory of Biochemistry and Molecular Biology, Tomsk State University Tomsk, Russia
| | - David Banks
- Systems, Power and Energy, School of Engineering, Glasgow UniversityGlasgow, UK; Holymoor Consultancy Ltd.Chesterfield, UK
| | - Alexey V Beletsky
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
| | - Andrey V Mardanov
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
| | - Elena I Sen'kina
- Laboratory of Biochemistry and Molecular Biology, Tomsk State University Tomsk, Russia
| | - Marat R Avakyan
- Laboratory of Biochemistry and Molecular Biology, Tomsk State University Tomsk, Russia
| | - Olga V Karnachuk
- Laboratory of Biochemistry and Molecular Biology, Tomsk State University Tomsk, Russia
| | - Nikolai V Ravin
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
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133
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Quorum Sensing and the Use of Quorum Quenchers as Natural Biocides to Inhibit Sulfate-Reducing Bacteria. Antibiotics (Basel) 2016; 5:antibiotics5040039. [PMID: 27983678 PMCID: PMC5187520 DOI: 10.3390/antibiotics5040039] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/23/2016] [Accepted: 12/06/2016] [Indexed: 11/17/2022] Open
Abstract
Sulfate-reducing bacteria (SRB) are one of the main protagonist groups of biocorrosion in the seawater environment. Given their principal role in biocorrosion, it remains a crucial task to develop strategies to reduce the abundance of SRBs. Conventional approaches include the use of biocides and antibiotics, which can impose health, safety, and environmental concerns. This review examines an alternative approach to this problem. This is achieved by reviewing the role of quorum sensing (QS) in SRB populations and its impact on the biofilm formation process. Genome databases of SRBs are mined to look for putative QS systems and homologous protein sequences representative of autoinducer receptors or synthases. Subsequently, this review puts forward the potential use of quorum quenchers as natural biocides against SRBs and outlines the potential strategies for the implementation of this approach.
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134
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Wöhlbrand L, Ruppersberg HS, Feenders C, Blasius B, Braun HP, Rabus R. Analysis of membrane-protein complexes of the marine sulfate reducer Desulfobacula toluolica Tol2 by 1D blue native-PAGE complexome profiling and 2D blue native-/SDS-PAGE. Proteomics 2016; 16:973-88. [PMID: 26792001 DOI: 10.1002/pmic.201500360] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 12/16/2015] [Accepted: 12/30/2015] [Indexed: 02/03/2023]
Abstract
Sulfate-reducing bacteria (SRB) obtain energy from cytoplasmic reduction of sulfate to sulfide involving APS-reductase (AprAB) and dissimilatory sulfite reductase (DsrAB). These enzymes are predicted to obtain electrons from membrane redox complexes, i.e. the quinone-interacting membrane-bound oxidoreductase (QmoABC) and DsrMKJOP complexes. In addition to these conserved complexes, the genomes of SRB encode a large number of other (predicted) membrane redox complexes, the function and actual formation of which is unknown. This study reports the establishment of 1D Blue Native-PAGE complexome profiling and 2D BN-/SDS-PAGE for analysis of the membrane protein complexome of the marine sulfate reducer Desulfobacula toluolica Tol2. Analysis of normalized score profiles of >800 proteins in combination with hierarchical clustering and identification of 2D BN-/SDS-PAGE separated spots demonstrated separation of membrane complexes in their native form, e.g. ATP synthase. In addition to the QmoABC and DsrMKJOP complexes, other complexes were detected that constitute the basic membrane complexome of D. toluolica Tol2, e.g. transport proteins (e.g. sodium/sulfate symporters) or redox complexes involved in Na(+) -based bioenergetics (RnfABCDEG). Notably, size estimation indicates dimer and quadruple formation of the DsrMKJOP complex in vivo. Furthermore, cluster analysis suggests interaction of this complex with a rhodanese-like protein (Tol2_C05230) possibly representing a periplasmic electron transfer partner for DsrMKJOP.
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Affiliation(s)
- Lars Wöhlbrand
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Hanna S Ruppersberg
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Christoph Feenders
- Mathematical Modelling, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Bernd Blasius
- Mathematical Modelling, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Hans-Peter Braun
- Plant Proteomics, Institute of Plant Genetics, Leibniz University Hannover, Hannover, Germany
| | - Ralf Rabus
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg, Oldenburg, Germany
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135
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Dörries M, Wöhlbrand L, Kube M, Reinhardt R, Rabus R. Genome and catabolic subproteomes of the marine, nutritionally versatile, sulfate-reducing bacterium Desulfococcus multivorans DSM 2059. BMC Genomics 2016; 17:918. [PMID: 27846794 PMCID: PMC5109826 DOI: 10.1186/s12864-016-3236-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 11/01/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sulfate-reducing bacteria (SRB) are key players of the carbon- and sulfur-cycles in the sediments of the world's oceans. Habitat relevant SRBs are often members of the Desulfosarcina-Desulfococcus clade belonging to the deltaproteobacterial family of Desulfobacteraceae. Despite this environmental recognition, their molecular (genome-based) physiology and their potential to contribute to organic carbon mineralization as well as to adapt to changing environmental conditions have been scarcely investigated. A metabolically versatile representative of this family is Desulfococcus multivorans that is able to completely oxidize (to CO2) a variety of organic acids, including fatty acids up to C14, as well as aromatic compounds. RESULTS In this study the complete 4.46 Mbp and manually annotated genome of metabolically versatile Desulfococcus multivorans DSM 2059 is presented with particular emphasis on a proteomics-driven metabolic reconstruction. Proteomic profiling covered 17 substrate adaptation conditions (6 aromatic and 11 aliphatic compounds) and comprised 2D DIGE, shotgun proteomics and analysis of the membrane protein-enriched fractions. This comprehensive proteogenomic dataset allowed for reconstructing a metabolic network of degradation pathways and energy metabolism that consists of 170 proteins (154 detected; ~91 % coverage). Peripheral degradation routes feed via central benzoyl-CoA, (modified) β-oxidation or methylmalonyl-CoA pathways into the Wood-Ljungdahl pathway for complete oxidation of acetyl-CoA to CO2. Dissimilatory sulfate reduction is fueled by a complex electron transfer network composed of cytoplasmic components (e.g., electron transfer flavoproteins) and diverse membrane redox complexes (Dsr, Qmo, Hmc, Tmc, Qrc, Nuo and Rnf). Overall, a high degree of substrate-specific formation of catabolic enzymes was observed, while most complexes involved in electron transfer appeared to be constitutively formed. CONCLUSIONS A highly dynamic genome structure in combination with substrate-specifically formed catabolic subproteomes and a constitutive subproteome for energy metabolism and electron transfer appears to be a common trait of Desulfobacteraceae members.
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Affiliation(s)
- Marvin Dörries
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Lars Wöhlbrand
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Michael Kube
- Institute of Forest Genetics, Johann Heinrich von Thünen Institute, Waldsieversdorf, Germany
| | | | - Ralf Rabus
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Max Planck Institute for Marine Microbiology, Bremen, Germany
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136
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Kuwahara H, Yuki M, Izawa K, Ohkuma M, Hongoh Y. Genome of 'Ca. Desulfovibrio trichonymphae', an H 2-oxidizing bacterium in a tripartite symbiotic system within a protist cell in the termite gut. ISME JOURNAL 2016; 11:766-776. [PMID: 27801909 PMCID: PMC5322295 DOI: 10.1038/ismej.2016.143] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 08/19/2016] [Accepted: 09/02/2016] [Indexed: 11/23/2022]
Abstract
The cellulolytic protist Trichonympha agilis in the termite gut permanently hosts two symbiotic bacteria, ‘Candidatus Endomicrobium trichonymphae' and ‘Candidatus Desulfovibrio trichonymphae'. The former is an intracellular symbiont, and the latter is almost intracellular but still connected to the outside via a small pore. The complete genome of ‘Ca. Endomicrobium trichonymphae' has previously been reported, and we here present the complete genome of ‘Ca. Desulfovibrio trichonymphae'. The genome is small (1 410 056 bp), has many pseudogenes, and retains biosynthetic pathways for various amino acids and cofactors, which are partially complementary to those of ‘Ca. Endomicrobium trichonymphae'. An amino acid permease gene has apparently been transferred between the ancestors of these two symbionts; a lateral gene transfer has affected their metabolic capacity. Notably, ‘Ca. Desulfovibrio trichonymphae' retains the complex system to oxidize hydrogen by sulfate and/or fumarate, while genes for utilizing other substrates common in desulfovibrios are pseudogenized or missing. Thus, ‘Ca. Desulfovibrio trichonymphae' is specialized to consume hydrogen that may otherwise inhibit fermentation processes in both T. agilis and ‘Ca. Endomicrobium trichonymphae'. The small pore may be necessary to take up sulfate. This study depicts a genome-based model of a multipartite symbiotic system within a cellulolytic protist cell in the termite gut.
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Affiliation(s)
- Hirokazu Kuwahara
- Department of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan
| | - Masahiro Yuki
- Biomass Research Platform Team, RIKEN Biomass Engineering Program Cooperation Division, RIKEN Center for Sustainable Resource Science, Tsukuba, Japan
| | - Kazuki Izawa
- Department of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan
| | - Moriya Ohkuma
- Biomass Research Platform Team, RIKEN Biomass Engineering Program Cooperation Division, RIKEN Center for Sustainable Resource Science, Tsukuba, Japan.,Japan Collection of Microorganisms, RIKEN BioResource Center, Tsukuba, Japan
| | - Yuichi Hongoh
- Department of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan.,Japan Collection of Microorganisms, RIKEN BioResource Center, Tsukuba, Japan
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137
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Jugder BE, Ertan H, Wong YK, Braidy N, Manefield M, Marquis CP, Lee M. Genomic, transcriptomic and proteomic analyses of Dehalobacter UNSWDHB in response to chloroform. ENVIRONMENTAL MICROBIOLOGY REPORTS 2016; 8:814-824. [PMID: 27452500 DOI: 10.1111/1758-2229.12444] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 07/25/2016] [Indexed: 06/06/2023]
Abstract
Organohalide respiring bacteria (ORB) are capable of utilising organohalides as electron acceptors for the generation of cellular energy and consequently play an important role in the turnover of natural and anthropogenically-derived organohalides. In this study, the response of a Dehalobacter sp. strain UNSWDHB to the addition of trichloromethane (TCM) after a 50 h period of its absence (suffocation) was evaluated from a transcriptomic and proteomic perspective. The up-regulation of TCM reductive dehalogenase genes (tmrABC) and their gene products (TmrABC) was confirmed at both transcriptional and proteomic levels. Other findings include the upregulation of various hydrogenases (membrane-associated Ni-Fe hydrogenase complexes and soluble Fe-Fe hydrogenases), formate dehydrogenases, complex I and a pyrophosphate-energized proton pump. The elevated expression of enzymes associated with carbon metabolism, including complete Wood Ljungdahl pathway, during TCM respiration raises interesting questions on possible fates of intracellular formate and its potential role in the physiology of this bacterium. Overall, the findings presented here provide a broader view on the bioenergetics and general physiology of Dehalobacter UNSWDHB cells actively respiring with TCM.
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Affiliation(s)
- Bat-Erdene Jugder
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, 2052, Australia
| | - Haluk Ertan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, 2052, Australia
- Department of Molecular Biology and Genetics, Istanbul University, Turkey
| | - Yie Kuan Wong
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, 2052, Australia
| | - Nady Braidy
- Faculty of Medicine, School of Psychiatry, Centre for Healthy Brain Ageing, University of New South Wales, Sydney, Australia
| | - Michael Manefield
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, 2052, Australia
| | - Christopher P Marquis
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, 2052, Australia
| | - Matthew Lee
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, 2052, Australia
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138
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Melton ED, Sorokin DY, Overmars L, Chertkov O, Clum A, Pillay M, Ivanova N, Shapiro N, Kyrpides NC, Woyke T, Lapidus AL, Muyzer G. Complete genome sequence of Desulfurivibrio alkaliphilus strain AHT2(T), a haloalkaliphilic sulfidogen from Egyptian hypersaline alkaline lakes. Stand Genomic Sci 2016; 11:67. [PMID: 27617057 PMCID: PMC5016858 DOI: 10.1186/s40793-016-0184-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 08/25/2016] [Indexed: 11/18/2022] Open
Abstract
Desulfurivibrio alkaliphilus strain AHT2T is a strictly anaerobic sulfidogenic haloalkaliphile isolated from a composite sediment sample of eight hypersaline alkaline lakes in the Wadi al Natrun valley in the Egyptian Libyan Desert. D. alkaliphilus AHT2T is Gram-negative and belongs to the family Desulfobulbaceae within the Deltaproteobacteria. Here we report its genome sequence, which contains a 3.10 Mbp chromosome. D. alkaliphilus AHT2T is adapted to survive under highly alkaline and moderately saline conditions and therefore, is relevant to the biotechnology industry and life under extreme conditions. For these reasons, D. alkaliphilus AHT2T was sequenced by the DOE Joint Genome Institute as part of the Community Science Program.
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Affiliation(s)
- Emily Denise Melton
- Microbial Systems Ecology, Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Dimitry Y Sorokin
- Winogradsky Institute of Microbiology, Research Centre of Biotechnology, RAS, Moscow, Russia ; Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Lex Overmars
- Microbial Systems Ecology, Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Olga Chertkov
- Bioscience Division, Department of Energy Joint Genome Institute, Los Alamos National Laboratory, Los Alamos, NM 87545 USA
| | - Alicia Clum
- Joint Genome Institute, Walnut Creek, CA USA
| | - Manoj Pillay
- Biological Data Management and Technology Center, Lawrence Berkeley National Laboratory, Berkeley, CA USA
| | | | | | - Nikos C Kyrpides
- Joint Genome Institute, Walnut Creek, CA USA ; Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Tanja Woyke
- Joint Genome Institute, Walnut Creek, CA USA
| | - Alla L Lapidus
- Center for Algorithmic Biotechnology, Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg, Russia
| | - Gerard Muyzer
- Microbial Systems Ecology, Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
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139
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Willis Poratti G, Yaakop AS, Chan CS, Urbieta MS, Chan KG, Ee R, Tan-Guan-Sheng A, Goh KM, Donati ER. Draft Genome Sequence of the Sulfate-Reducing Bacterium Desulfotomaculum copahuensis Strain CINDEFI1 Isolated from the Geothermal Copahue System, Neuquén, Argentina. GENOME ANNOUNCEMENTS 2016; 4:4/4/e00870-16. [PMID: 27540078 PMCID: PMC4991723 DOI: 10.1128/genomea.00870-16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Desulfotomaculum copahuensis strain CINDEFI1 is a novel spore-forming sulfate-reducing bacterium isolated from the Copahue volcano area, Argentina. Here, we present its draft genome in which we found genes related with the anaerobic respiration of sulfur compounds similar to those present in the Copahue environment.
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Affiliation(s)
- Graciana Willis Poratti
- CINDEFI (CCT, La Plata-CONICET, UNLP), Facultad de Ciencias Exactas, Universidad Nacional de la Plata, La Plata, Argentina
| | - Amira Suriaty Yaakop
- Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia
| | - Chia Sing Chan
- Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia
| | - M Sofía Urbieta
- CINDEFI (CCT, La Plata-CONICET, UNLP), Facultad de Ciencias Exactas, Universidad Nacional de la Plata, La Plata, Argentina
| | - Kok-Gan Chan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Robson Ee
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Adrian Tan-Guan-Sheng
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Kian Mau Goh
- Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia
| | - Edgardo R Donati
- CINDEFI (CCT, La Plata-CONICET, UNLP), Facultad de Ciencias Exactas, Universidad Nacional de la Plata, La Plata, Argentina
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140
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Narihiro T, Nobu MK, Tamaki H, Kamagata Y, Sekiguchi Y, Liu WT. Comparative Genomics of Syntrophic Branched-Chain Fatty Acid Degrading Bacteria. Microbes Environ 2016; 31:288-92. [PMID: 27431485 PMCID: PMC5017805 DOI: 10.1264/jsme2.me16057] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The syntrophic degradation of branched-chain fatty acids (BCFAs) such as 2-methylbutyrate and isobutyrate is an essential step in the production of methane from proteins/amino acids in anaerobic ecosystems. While a few syntrophic BCFA-degrading bacteria have been isolated, their metabolic pathways in BCFA and short-chain fatty acid (SCFA) degradation as well as energy conservation systems remain unclear. In an attempt to identify these pathways, we herein performed comparative genomics of three syntrophic bacteria: 2-methylbutyrate-degrading “Syntrophomonas wolfei subsp. methylbutyratica” strain JCM 14075T (=4J5T), isobutyrate-degrading Syntrophothermus lipocalidus strain TGB-C1T, and non-BCFA-metabolizing S. wolfei subsp. wolfei strain GöttingenT. We demonstrated that 4J5 and TGB-C1 both encode multiple genes/gene clusters involved in β-oxidation, as observed in the Göttingen genome, which has multiple copies of genes associated with butyrate degradation. The 4J5 genome possesses phylogenetically distinct β-oxidation genes, which may be involved in 2-methylbutyrate degradation. In addition, these Syntrophomonadaceae strains harbor various hydrogen/formate generation systems (i.e., electron-bifurcating hydrogenase, formate dehydrogenase, and membrane-bound hydrogenase) and energy-conserving electron transport systems, including electron transfer flavoprotein (ETF)-linked acyl-CoA dehydrogenase, ETF-linked iron-sulfur binding reductase, ETF dehydrogenase (FixABCX), and flavin oxidoreductase-heterodisulfide reductase (Flox-Hdr). Unexpectedly, the TGB-C1 genome encodes a nitrogenase complex, which may function as an alternative H2 generation mechanism. These results suggest that the BCFA-degrading syntrophic strains 4J5 and TGB-C1 possess specific β-oxidation-related enzymes for BCFA oxidation as well as appropriate energy conservation systems to perform thermodynamically unfavorable syntrophic metabolism.
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Affiliation(s)
- Takashi Narihiro
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST)
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141
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Abstract
Acetogenic bacteria are a diverse group of strictly anaerobic bacteria that utilize the Wood-Ljungdahl pathway for CO2 fixation and energy conservation. These microorganisms play an important part in the global carbon cycle and are a key component of the anaerobic food web. Their most prominent metabolic feature is autotrophic growth with molecular hydrogen and carbon dioxide as the substrates. However, most members also show an outstanding metabolic flexibility for utilizing a vast variety of different substrates. In contrast to autotrophic growth, which is hardly competitive, metabolic flexibility is seen as a key ability of acetogens to compete in ecosystems and might explain the almost-ubiquitous distribution of acetogenic bacteria in anoxic environments. This review covers the latest findings with respect to the heterotrophic metabolism of acetogenic bacteria, including utilization of carbohydrates, lactate, and different alcohols, especially in the model acetogen Acetobacterium woodii Modularity of metabolism, a key concept of pathway design in synthetic biology, together with electron bifurcation, to overcome energetic barriers, appears to be the basis for the amazing substrate spectrum. At the same time, acetogens depend on only a relatively small number of enzymes to expand the substrate spectrum. We will discuss the energetic advantages of coupling CO2 reduction to fermentations that exploit otherwise-inaccessible substrates and the ecological advantages, as well as the biotechnological applications of the heterotrophic metabolism of acetogens.
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142
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Leavitt WD, Flynn TM, Suess MK, Bradley AS. Transhydrogenase and Growth Substrate Influence Lipid Hydrogen Isotope Ratios in Desulfovibrio alaskensis G20. Front Microbiol 2016; 7:918. [PMID: 27445998 PMCID: PMC4916218 DOI: 10.3389/fmicb.2016.00918] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 05/27/2016] [Indexed: 11/19/2022] Open
Abstract
Microbial fatty acids preserve metabolic and environmental information in their hydrogen isotope ratios ((2)H/(1)H). This ratio is influenced by parameters that include the (2)H/(1)H of water in the microbial growth environment, and biosynthetic fractionations between water and lipid. In some microbes, this biosynthetic fractionation has been shown to vary systematically with central energy metabolism, and controls on fatty acid (2)H/(1)H may be linked to the intracellular production of NADPH. We examined the apparent fractionation between media water and the fatty acids produced by Desulfovibrio alaskensis G20. Growth was in batch culture with malate as an electron donor for sulfate respiration, and with pyruvate and fumarate as substrates for fermentation and for sulfate respiration. A larger fractionation was observed as a consequence of respiratory or fermentative growth on pyruvate than growth on fumarate or malate. This difference correlates with opposite apparent flows of electrons through the electron bifurcating/confurcating transhydrogenase NfnAB. When grown on malate or fumarate, mutant strains of D. alaskensis G20 containing transposon disruptions in a copy of nfnAB show different fractionations than the wild type strain. This phenotype is muted during fermentative growth on pyruvate, and it is absent when pyruvate is a substrate for sulfate reduction. All strains and conditions produced similar fatty acid profiles, and the (2)H/(1)H of individual lipids changed in concert with the mass-weighted average. Unsaturated fatty acids were generally depleted in (2)H relative to their saturated homologs, and anteiso-branched fatty acids were generally depleted in (2)H relative to straight-chain fatty acids. Fractionation correlated with growth rate, a pattern that has also been observed in the fractionation of sulfur isotopes during dissimilatory sulfate reduction by sulfate-reducing bacteria.
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Affiliation(s)
- William D. Leavitt
- Department of Earth and Planetary Sciences, Washington University in St. LouisSaint Louis, MO, USA
| | | | - Melanie K. Suess
- Department of Earth and Planetary Sciences, Washington University in St. LouisSaint Louis, MO, USA
| | - Alexander S. Bradley
- Department of Earth and Planetary Sciences, Washington University in St. LouisSaint Louis, MO, USA
- Division of Biology and Biomedical Sciences, Washington University in St. LouisSaint Louis, MO, USA
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143
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Mardanov AV, Beletsky AV, Kadnikov VV, Slobodkin AI, Ravin NV. Genome Analysis of Thermosulfurimonas dismutans, the First Thermophilic Sulfur-Disproportionating Bacterium of the Phylum Thermodesulfobacteria. Front Microbiol 2016; 7:950. [PMID: 27379079 PMCID: PMC4911364 DOI: 10.3389/fmicb.2016.00950] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 06/02/2016] [Indexed: 11/17/2022] Open
Abstract
Thermosulfurimonas dismutans S95T, isolated from a deep-sea hydrothermal vent is the first bacterium of the phylum Thermodesulfobacteria reported to grow by the disproportionation of elemental sulfur, sulfite, or thiosulfate with carbon dioxide as the sole carbon source. In contrast to its phylogenetically close relatives, which are dissimilatory sulfate-reducers, T. dismutans is unable to grow by sulfate respiration. The features of this organism and its 2,1 Mb draft genome sequence are described in this report. Genome analysis revealed that the T. dismutans genome contains the set of genes for dissimilatory sulfate reduction including ATP sulfurylase, the AprA and B subunits of adenosine-5′-phosphosulfate reductase, and dissimilatory sulfite reductase. The oxidation of elemental sulfur to sulfite could be enabled by APS reductase-associated electron transfer complex QmoABC and heterodisulfide reductase. The genome also contains several membrane-linked molybdopterin oxidoreductases that are thought to be involved in sulfur metabolism as subunits of thiosulfate, polysulfide, or tetrathionate reductases. Nitrate could be used as an electron acceptor and reduced to ammonium, as indicated by the presence of periplasmic nitrate and nitrite reductases. Autotrophic carbon fixation is enabled by the Wood–Ljungdahl pathway, and the complete set of genes that is required for nitrogen fixation is also present in T. dismutans. Overall, our results provide genomic insights into energy and carbon metabolism of chemolithoautotrophic sulfur-disproportionating bacterium that could be important primary producer in microbial communities of deep-sea hydrothermal vents.
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Affiliation(s)
- Andrey V Mardanov
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
| | - Alexey V Beletsky
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
| | - Vitaly V Kadnikov
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
| | - Alexander I Slobodkin
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
| | - Nikolai V Ravin
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia
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144
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Perez-Garcia O, Lear G, Singhal N. Metabolic Network Modeling of Microbial Interactions in Natural and Engineered Environmental Systems. Front Microbiol 2016; 7:673. [PMID: 27242701 PMCID: PMC4870247 DOI: 10.3389/fmicb.2016.00673] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 04/25/2016] [Indexed: 12/14/2022] Open
Abstract
We review approaches to characterize metabolic interactions within microbial communities using Stoichiometric Metabolic Network (SMN) models for applications in environmental and industrial biotechnology. SMN models are computational tools used to evaluate the metabolic engineering potential of various organisms. They have successfully been applied to design and optimize the microbial production of antibiotics, alcohols and amino acids by single strains. To date however, such models have been rarely applied to analyze and control the metabolism of more complex microbial communities. This is largely attributed to the diversity of microbial community functions, metabolisms, and interactions. Here, we firstly review different types of microbial interaction and describe their relevance for natural and engineered environmental processes. Next, we provide a general description of the essential methods of the SMN modeling workflow including the steps of network reconstruction, simulation through Flux Balance Analysis (FBA), experimental data gathering, and model calibration. Then we broadly describe and compare four approaches to model microbial interactions using metabolic networks, i.e., (i) lumped networks, (ii) compartment per guild networks, (iii) bi-level optimization simulations, and (iv) dynamic-SMN methods. These approaches can be used to integrate and analyze diverse microbial physiology, ecology and molecular community data. All of them (except the lumped approach) are suitable for incorporating species abundance data but so far they have been used only to model simple communities of two to eight different species. Interactions based on substrate exchange and competition can be directly modeled using the above approaches. However, interactions based on metabolic feedbacks, such as product inhibition and synthropy require extensions to current models, incorporating gene regulation and compounding accumulation mechanisms. SMN models of microbial interactions can be used to analyze complex “omics” data and to infer and optimize metabolic processes. Thereby, SMN models are suitable to capitalize on advances in high-throughput molecular and metabolic data generation. SMN models are starting to be applied to describe microbial interactions during wastewater treatment, in-situ bioremediation, microalgae blooms methanogenic fermentation, and bioplastic production. Despite their current challenges, we envisage that SMN models have future potential for the design and development of novel growth media, biochemical pathways and synthetic microbial associations.
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Affiliation(s)
- Octavio Perez-Garcia
- Department of Civil and Environmental Engineering, University of Auckland Auckland, New Zealand
| | - Gavin Lear
- School of Biological Sciences, The University of Auckland Auckland, New Zealand
| | - Naresh Singhal
- Department of Civil and Environmental Engineering, University of Auckland Auckland, New Zealand
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145
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Wasmund K, Cooper M, Schreiber L, Lloyd KG, Baker BJ, Petersen DG, Jørgensen BB, Stepanauskas R, Reinhardt R, Schramm A, Loy A, Adrian L. Single-Cell Genome and Group-Specific dsrAB Sequencing Implicate Marine Members of the Class Dehalococcoidia (Phylum Chloroflexi) in Sulfur Cycling. mBio 2016; 7:e00266-16. [PMID: 27143384 PMCID: PMC4959651 DOI: 10.1128/mbio.00266-16] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 04/05/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The marine subsurface sediment biosphere is widely inhabited by bacteria affiliated with the class Dehalococcoidia (DEH), phylum Chloroflexi, and yet little is known regarding their metabolisms. In this report, genomic content from a single DEH cell (DEH-C11) with a 16S rRNA gene that was affiliated with a diverse cluster of 16S rRNA gene sequences prevalent in marine sediments was obtained from sediments of Aarhus Bay, Denmark. The distinctive gene content of this cell suggests metabolic characteristics that differ from those of known DEH and Chloroflexi The presence of genes encoding dissimilatory sulfite reductase (Dsr) suggests that DEH could respire oxidized sulfur compounds, although Chloroflexi have never been implicated in this mode of sulfur cycling. Using long-range PCR assays targeting DEH dsr loci, dsrAB genes were amplified and sequenced from various marine sediments. Many of the amplified dsrAB sequences were affiliated with the DEH Dsr clade, which we propose equates to a family-level clade. This provides supporting evidence for the potential for sulfite reduction by diverse DEH species. DEH-C11 also harbored genes encoding reductases for arsenate, dimethyl sulfoxide, and halogenated organics. The reductive dehalogenase homolog (RdhA) forms a monophyletic clade along with RdhA sequences from various DEH-derived contigs retrieved from available metagenomes. Multiple facts indicate that this RdhA may not be a terminal reductase. The presence of other genes indicated that nutrients and energy may be derived from the oxidation of substituted homocyclic and heterocyclic aromatic compounds. Together, these results suggest that marine DEH play a previously unrecognized role in sulfur cycling and reveal the potential for expanded catabolic and respiratory functions among subsurface DEH. IMPORTANCE Sediments underlying our oceans are inhabited by microorganisms in cell numbers similar to those estimated to inhabit the oceans. Microorganisms in sediments consist of various diverse and uncharacterized groups that contribute substantially to global biogeochemical cycles. Since most subsurface microorganisms continue to evade cultivation, possibly due to very slow growth, we obtained and analyzed genomic information from a representative of one of the most widespread and abundant, yet uncharacterized bacterial groups of the marine subsurface. We describe several key features that may contribute to their widespread distribution, such as respiratory flexibility and the potential to use oxidized sulfur compounds, which are abundant in marine environments, as electron acceptors. Together, these data provide important information that can be used to assist in designing enrichment strategies or other postgenomic studies, while also improving our understanding of the diversity and distribution of dsrAB genes, which are widely used functional marker genes for sulfur-cycling microbes.
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Affiliation(s)
- Kenneth Wasmund
- Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Research Network Chemistry meets Microbiology, University of Vienna, Vienna, Austria
| | - Myriel Cooper
- Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Lars Schreiber
- Department of Bioscience, Center for Geomicrobiology, Aarhus University, Aarhus, Denmark
| | - Karen G Lloyd
- Department of Bioscience, Center for Geomicrobiology, Aarhus University, Aarhus, Denmark
| | - Brett J Baker
- Department of Marine Science, University of Texas-Austin, Marine Science Institute, Port Aransas, Texas, USA
| | - Dorthe G Petersen
- Department of Bioscience, Center for Geomicrobiology, Aarhus University, Aarhus, Denmark
| | - Bo Barker Jørgensen
- Department of Bioscience, Center for Geomicrobiology, Aarhus University, Aarhus, Denmark
| | | | | | - Andreas Schramm
- Department of Bioscience, Center for Geomicrobiology, Aarhus University, Aarhus, Denmark
| | - Alexander Loy
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Research Network Chemistry meets Microbiology, University of Vienna, Vienna, Austria
| | - Lorenz Adrian
- Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
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146
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Wang L, Bradstock P, Li C, McInerney MJ, Krumholz LR. The role of Rnf in ion gradient formation in Desulfovibrio alaskensis. PeerJ 2016; 4:e1919. [PMID: 27114876 PMCID: PMC4841214 DOI: 10.7717/peerj.1919] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Accepted: 03/19/2016] [Indexed: 02/05/2023] Open
Abstract
Rnf is a membrane protein complex that has been shown to be important in energy conservation. Here, Desulfovibrio alaskensis G20 and Rnf mutants of G20 were grown with different electron donor and acceptor combinations to determine the importance of Rnf in energy conservation and the type of ion gradient generated. The addition of the protonophore TCS strongly inhibited lactate-sulfate dependent growth whereas the sodium ionophore ETH2120 had no effect, indicating a role for the proton gradient during growth. Mutants in rnfA and rnfD were more sensitive to the protonophore at 5 µM than the parental strain, suggesting the importance of Rnf in the generation of a proton gradient. The electrical potential (ΔΨ), ΔpH and proton motive force were lower in the rnfA mutant than in the parental strain of D.alaskensis G20. These results provide evidence that the Rnf complex in D. alaskensis functions as a primary proton pump whose activity is important for growth.
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Affiliation(s)
- Luyao Wang
- Department of Microbiology and Plant Biology, University of Oklahoma , Norman, Oklahoma , USA
| | - Peter Bradstock
- Department of Microbiology and Plant Biology, University of Oklahoma , Norman, Oklahoma , USA
| | - Chuang Li
- Department of Microbiology and Plant Biology, University of Oklahoma , Norman, Oklahoma , USA
| | - Michael J McInerney
- Department of Microbiology and Plant Biology, University of Oklahoma , Norman, Oklahoma , USA
| | - Lee R Krumholz
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma, USA; Institute for Energy and the Environment, University of Oklahoma, Norman, Oklahoma, USA
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147
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Genome Sequence of the Piezophilic, Mesophilic Sulfate-Reducing Bacterium Desulfovibrio indicus J2T. GENOME ANNOUNCEMENTS 2016; 4:4/2/e00214-16. [PMID: 27056223 PMCID: PMC4824256 DOI: 10.1128/genomea.00214-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The complete genome sequence of Desulfovibrio indicus J2T, a member of the family Desulfovibrionaceae, consists of 3,966,573-bp in one contig and encodes 3,461 predicted genes, 5 noncoding RNAs, 3 rRNAs operons, and 52 tRNA-encoding genes. The genome is consistent with a heterotrophic, anaerobic lifestyle including the sulfate reduction pathway.
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148
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Krukenberg V, Harding K, Richter M, Glöckner FO, Gruber-Vodicka HR, Adam B, Berg JS, Knittel K, Tegetmeyer HE, Boetius A, Wegener G. CandidatusDesulfofervidus auxilii, a hydrogenotrophic sulfate-reducing bacterium involved in the thermophilic anaerobic oxidation of methane. Environ Microbiol 2016; 18:3073-91. [DOI: 10.1111/1462-2920.13283] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 02/23/2016] [Accepted: 02/24/2016] [Indexed: 01/20/2023]
Affiliation(s)
| | - Katie Harding
- Max Planck Institute for Marine Microbiology; Bremen Germany
| | - Michael Richter
- Max Planck Institute for Marine Microbiology; Bremen Germany
| | - Frank Oliver Glöckner
- Max Planck Institute for Marine Microbiology; Bremen Germany
- Jacobs University Bremen gGmbH; Bremen Germany
| | | | - Birgit Adam
- Max Planck Institute for Marine Microbiology; Bremen Germany
| | - Jasmine S. Berg
- Max Planck Institute for Marine Microbiology; Bremen Germany
| | - Katrin Knittel
- Max Planck Institute for Marine Microbiology; Bremen Germany
| | - Halina E. Tegetmeyer
- Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research; Bremerhaven Germany
- Center for Biotechnology, Bielefeld University; Bielefeld Germany
| | - Antje Boetius
- Max Planck Institute for Marine Microbiology; Bremen Germany
- Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research; Bremerhaven Germany
- MARUM, Center for Marine Environmental Sciences, University Bremen; Bremen Germany
| | - Gunter Wegener
- Max Planck Institute for Marine Microbiology; Bremen Germany
- MARUM, Center for Marine Environmental Sciences, University Bremen; Bremen Germany
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149
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Cao H, Dong C, Bougouffa S, Li J, Zhang W, Shao Z, Bajic VB, Qian PY. Delta-proteobacterial SAR324 group in hydrothermal plumes on the South Mid-Atlantic Ridge. Sci Rep 2016; 6:22842. [PMID: 26953077 PMCID: PMC4782131 DOI: 10.1038/srep22842] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 02/23/2016] [Indexed: 11/17/2022] Open
Abstract
In the dark ocean, the SAR324 group of Delta-proteobacteria has been associated with a chemolithotrophic lifestyle. However, their electron transport chain for energy generation and information system has not yet been well characterized. In the present study, four SAR324 draft genomes were extracted from metagenomes sampled from hydrothermal plumes in the South Mid-Atlantic Ridge. We describe novel electron transport chain components in the SAR324 group, particularly the alternative complex III, which is involved in energy generation. Moreover, we propose that the C-type cytochrome, for example the C553, may play a novel role in electron transfer, adding to our knowledge regarding the energy generation process in the SAR324 cluster. The central carbon metabolism in the described SAR324 genomes exhibits several new features other than methanotrophy e.g. aromatic compound degradation. This suggests that methane oxidation may not be the main central carbon metabolism component in SAR324 cluster bacteria. The reductive acetyl-CoA pathway may potentially be essential in carbon fixation due to the absence of components from the Calvin-Benson cycle. Our study provides insight into the role of recombination events in shaping the genome of the SAR324 group based on a larger number of repeat regions observed, which has been overlooked thus far.
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Affiliation(s)
- Huiluo Cao
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Chunming Dong
- Key Laboratory of Marine Biogenetic Resources, The Third Institute of Oceanography, State of Oceanic Administration, Xiamen, China
| | - Salim Bougouffa
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Jiangtao Li
- State Key Laboratory of Marine Geology, Tongji University, Shanghai, China
| | - Weipeng Zhang
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Zongze Shao
- Key Laboratory of Marine Biogenetic Resources, The Third Institute of Oceanography, State of Oceanic Administration, Xiamen, China
| | - Vladimir B Bajic
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Pei-Yuan Qian
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
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Otwell AE, Callister SJ, Zink EM, Smith RD, Richardson RE. Comparative Proteomic Analysis of Desulfotomaculum reducens MI-1: Insights into the Metabolic Versatility of a Gram-Positive Sulfate- and Metal-Reducing Bacterium. Front Microbiol 2016; 7:191. [PMID: 26925055 PMCID: PMC4759654 DOI: 10.3389/fmicb.2016.00191] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Accepted: 02/03/2016] [Indexed: 11/30/2022] Open
Abstract
The proteomes of the metabolically versatile and poorly characterized Gram-positive bacterium Desulfotomaculum reducens MI-1 were compared across four cultivation conditions including sulfate reduction, soluble Fe(III) reduction, insoluble Fe(III) reduction, and pyruvate fermentation. Collectively across conditions, we observed at high confidence ~38% of genome-encoded proteins. Here, we focus on proteins that display significant differential abundance on conditions tested. To the best of our knowledge, this is the first full-proteome study focused on a Gram-positive organism cultivated either on sulfate or metal-reducing conditions. Several proteins with uncharacterized function encoded within heterodisulfide reductase (hdr)-containing loci were upregulated on either sulfate (Dred_0633-4, Dred_0689-90, and Dred_1325-30) or Fe(III)-citrate-reducing conditions (Dred_0432-3 and Dred_1778-84). Two of these hdr-containing loci display homology to recently described flavin-based electron bifurcation (FBEB) pathways (Dred_1325-30 and Dred_1778-84). Additionally, we propose that a cluster of proteins, which is homologous to a described FBEB lactate dehydrogenase (LDH) complex, is performing lactate oxidation in D. reducens (Dred_0367-9). Analysis of the putative sulfate reduction machinery in D. reducens revealed that most of these proteins are constitutively expressed across cultivation conditions tested. In addition, peptides from the single multiheme c-type cytochrome (MHC) in the genome were exclusively observed on the insoluble Fe(III) condition, suggesting that this MHC may play a role in reduction of insoluble metals.
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Affiliation(s)
- Anne E Otwell
- Department of Microbiology, Cornell University Ithaca, NY, USA
| | - Stephen J Callister
- Pacific Northwest National Laboratory, Biological Sciences Division Richland, WA, USA
| | - Erika M Zink
- Pacific Northwest National Laboratory, Biological Sciences Division Richland, WA, USA
| | - Richard D Smith
- Pacific Northwest National Laboratory, Biological Sciences Division Richland, WA, USA
| | - Ruth E Richardson
- Department of Civil and Environmental Engineering, Cornell University Ithaca, NY, USA
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