1
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Sirohiwal A, Gamiz-Hernandez AP, Kaila VRI. Mechanistic Principles of Hydrogen Evolution in the Membrane-Bound Hydrogenase. J Am Chem Soc 2024; 146:18019-18031. [PMID: 38888987 PMCID: PMC11228991 DOI: 10.1021/jacs.4c04476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 05/22/2024] [Accepted: 05/23/2024] [Indexed: 06/20/2024]
Abstract
The membrane-bound hydrogenase (Mbh) from Pyrococcus furiosus is an archaeal member of the Complex I superfamily. It catalyzes the reduction of protons to H2 gas powered by a [NiFe] active site and transduces the free energy into proton pumping and Na+/H+ exchange across the membrane. Despite recent structural advances, the mechanistic principles of H2 catalysis and ion transport in Mbh remain elusive. Here, we probe how the redox chemistry drives the reduction of the proton to H2 and how the catalysis couples to conformational dynamics in the membrane domain of Mbh. By combining large-scale quantum chemical density functional theory (DFT) and correlated ab initio wave function methods with atomistic molecular dynamics simulations, we show that the proton transfer reactions required for the catalysis are gated by electric field effects that direct the protons by water-mediated reactions from Glu21L toward the [NiFe] site, or alternatively along the nearby His75L pathway that also becomes energetically feasible in certain reaction steps. These local proton-coupled electron transfer (PCET) reactions induce conformational changes around the active site that provide a key coupling element via conserved loop structures to the ion transport activity. We find that H2 forms in a heterolytic proton reduction step, with spin crossovers tuning the energetics along key reaction steps. On a general level, our work showcases the role of electric fields in enzyme catalysis and how these effects are employed by the [NiFe] active site of Mbh to drive PCET reactions and ion transport.
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Affiliation(s)
- Abhishek Sirohiwal
- Department of Biochemistry
and Biophysics, Stockholm University, Stockholm 10691, Sweden
| | - Ana P. Gamiz-Hernandez
- Department of Biochemistry
and Biophysics, Stockholm University, Stockholm 10691, Sweden
| | - Ville R. I. Kaila
- Department of Biochemistry
and Biophysics, Stockholm University, Stockholm 10691, Sweden
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2
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Thweatt JL, Harman CE, Araújo MN, Marlow JJ, Oliver GC, Sabuda MC, Sevgen S, Wilpiszeki RL. Chapter 6: The Breadth and Limits of Life on Earth. ASTROBIOLOGY 2024; 24:S124-S142. [PMID: 38498824 DOI: 10.1089/ast.2021.0131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
Scientific ideas about the potential existence of life elsewhere in the universe are predominantly informed by knowledge about life on Earth. Over the past ∼4 billion years, life on Earth has evolved into millions of unique species. Life now inhabits nearly every environmental niche on Earth that has been explored. Despite the wide variety of species and diverse biochemistry of modern life, many features, such as energy production mechanisms and nutrient requirements, are conserved across the Tree of Life. Such conserved features help define the operational parameters required by life and therefore help direct the exploration and evaluation of habitability in extraterrestrial environments. As new diversity in the Tree of Life continues to expand, so do the known limits of life on Earth and the range of environments considered habitable elsewhere. The metabolic processes used by organisms living on the edge of habitability provide insights into the types of environments that would be most suitable to hosting extraterrestrial life, crucial for planning and developing future astrobiology missions. This chapter will introduce readers to the breadth and limits of life on Earth and show how the study of life at the extremes can inform the broader field of astrobiology.
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Affiliation(s)
- Jennifer L Thweatt
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania, USA. (Former)
| | - C E Harman
- Planetary Systems Branch, NASA Ames Research Center, Moffett Field, California, USA
| | - M N Araújo
- Biochemistry Department, University of São Paulo, São Carlos, Brazil
| | - Jeffrey J Marlow
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | - Gina C Oliver
- Department of Geology, San Bernardino Valley College, San Bernardino, California, USA
| | - Mary C Sabuda
- Department of Earth and Environmental Sciences, University of Minnesota-Twin Cities, Minneapolis, Minnesota, USA
- Biotechnology Institute, University of Minnesota-Twin Cities, St. Paul, Minnesota, USA
| | - Serhat Sevgen
- Institute of Marine Sciences, Middle East Technical University, Erdemli, Mersin, Turkey
- Blue Marble Space Institute of Science, Seattle, Washington, USA
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3
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Sarkar S, Kazarina A, Hansen PM, Ward K, Hargreaves C, Reese N, Ran Q, Kessler W, de Souza LF, Loecke TD, Sarto MVM, Rice CW, Zeglin LH, Sikes BA, Lee ST. Ammonia-oxidizing archaea and bacteria differentially contribute to ammonia oxidation in soil under precipitation gradients and land legacy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.08.566028. [PMID: 37987001 PMCID: PMC10659370 DOI: 10.1101/2023.11.08.566028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Background Global change has accelerated the nitrogen cycle. Soil nitrogen stock degradation by microbes leads to the release of various gases, including nitrous oxide (N2O), a potent greenhouse gas. Ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) participate in the soil nitrogen cycle, producing N2O. There are outstanding questions regarding the impact of environmental processes such as precipitation and land use legacy on AOA and AOB structurally, compositionally, and functionally. To answer these questions, we analyzed field soil cores and soil monoliths under varying precipitation profiles and land legacies. Results We resolved 28 AOA and AOB metagenome assembled genomes (MAGs) and found that they were significantly higher in drier environments and differentially abundant in different land use legacies. We further dissected AOA and AOB functional potentials to understand their contribution to nitrogen transformation capabilities. We identified the involvement of stress response genes, differential metabolic functional potentials, and subtle population dynamics under different environmental parameters for AOA and AOB. We observed that AOA MAGs lacked a canonical membrane-bound electron transport chain and F-type ATPase but possessed A/A-type ATPase, while AOB MAGs had a complete complex III module and F-type ATPase, suggesting differential survival strategies of AOA and AOB. Conclusions The outcomes from this study will enable us to comprehend how drought-like environments and land use legacies could impact AOA- and AOB-driven nitrogen transformations in soil.
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Affiliation(s)
- Soumyadev Sarkar
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Anna Kazarina
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Paige M. Hansen
- PMH Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado USA
| | - Kaitlyn Ward
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | | | - Nicholas Reese
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Qinghong Ran
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Willow Kessler
- Department of Ecology & Evolutionary Biology, University of Kansas, Lawrence, Kansas, USA
| | - Ligia F.T. de Souza
- Department of Ecology & Evolutionary Biology, University of Kansas, Lawrence, Kansas, USA
| | - Terry D. Loecke
- Kansas Biological Survey and Center for Ecological Research, University of Kansas, Lawrence, Kansas, USA
- Environmental Studies Program, University of Kansas, Lawrence, Kansas, USA
| | | | - Charles W. Rice
- Department of Agronomy, Kansas State University, Manhattan, Kansas, USA
| | - Lydia H. Zeglin
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Benjamin A. Sikes
- Department of Ecology & Evolutionary Biology, University of Kansas, Lawrence, Kansas, USA
- Kansas Biological Survey and Center for Ecological Research, University of Kansas, Lawrence, Kansas, USA
| | - Sonny T.M. Lee
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
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4
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Xie Y, Erşan S, Guan X, Wang J, Sha J, Xu S, Wohlschlegel JA, Park JO, Liu C. Unexpected metabolic rewiring of CO 2 fixation in H 2-mediated materials-biology hybrids. Proc Natl Acad Sci U S A 2023; 120:e2308373120. [PMID: 37816063 PMCID: PMC10589654 DOI: 10.1073/pnas.2308373120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 08/31/2023] [Indexed: 10/12/2023] Open
Abstract
A hybrid approach combining water-splitting electrochemistry and H2-oxidizing, CO2-fixing microorganisms offers a viable solution for producing value-added chemicals from sunlight, water, and air. The classic wisdom without thorough examination to date assumes that the electrochemistry in such a H2-mediated process is innocent of altering microbial behavior. Here, we report unexpected metabolic rewiring induced by water-splitting electrochemistry in H2-oxidizing acetogenic bacterium Sporomusa ovata that challenges such a classic view. We found that the planktonic S. ovata is more efficient in utilizing reducing equivalent for ATP generation in the materials-biology hybrids than cells grown with H2 supply, supported by our metabolomic and proteomic studies. The efficiency of utilizing reducing equivalents and fixing CO2 into acetate has increased from less than 80% of chemoautotrophy to more than 95% under electroautotrophic conditions. These observations unravel previously underappreciated materials' impact on microbial metabolism in seemingly simply H2-mediated charge transfer between biotic and abiotic components. Such a deeper understanding of the materials-biology interface will foster advanced design of hybrid systems for sustainable chemical transformation.
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Affiliation(s)
- Yongchao Xie
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
| | - Sevcan Erşan
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA90095
| | - Xun Guan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
| | - Jingyu Wang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
| | - Jihui Sha
- Department of Biological Chemistry, University of California, Los Angeles, CA90095
| | - Shuangning Xu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
| | | | - Junyoung O. Park
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA90095
- California NanoSystems Institute, University of California, Los Angeles, CA90095
| | - Chong Liu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
- California NanoSystems Institute, University of California, Los Angeles, CA90095
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5
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Metatranscriptomic insights into the microbial electrosynthesis of acetate by Fe 2+/Ni 2+ addition. World J Microbiol Biotechnol 2023; 39:109. [PMID: 36879133 DOI: 10.1007/s11274-023-03554-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 02/21/2023] [Indexed: 03/08/2023]
Abstract
As important components of enzymes and coenzymes involved in energy transfer and Wood-Ljungdahl (WL) pathways, Fe2+ and Ni2+ supplementation may promote the acetate synthesis through CO2 reduction by the microbial electrosynthesis (MES). However, the effect of Fe2+ and Ni2+ addition on acetate production in MES and corresponding microbial mechanisms have not been fully studied. Therefore, this study investigated the effect of Fe2+ and Ni2+ addition on acetate production in MES, and explored the underlying microbial mechanism from the metatranscriptomic perspective. Both Fe2+ and Ni2+ addition enhanced acetate production of the MES, which was 76.9% and 110.9% higher than that of control, respectively. Little effect on phylum level and small changes in genus-level microbial composition was caused by Fe2+ and Ni2+ addition. Gene expression of 'Energy metabolism', especially in 'Carbon fixation pathways in prokaryotes' was up-regulated by Fe2+ and Ni2+ addition. Hydrogenase was found as an important energy transfer mediator for CO2 reduction and acetate synthesis. Fe2+ addition and Ni2+ addition respectively enhanced the expression of methyl branch and carboxyl branch of the WL pathway, and thus promoted acetate production. The study provided a metatranscriptomic insight into the effect of Fe2+ and Ni2+ on acetate production by CO2 reduction in MES.
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Wang G, Wang Y, Ni J, Li R, Zhu F, Wang R, Tian Q, Shen Q, Yang Q, Tang J, Murcha MW, Wang G. An MCIA-like complex is required for mitochondrial complex I assembly and seed development in maize. MOLECULAR PLANT 2022; 15:1470-1487. [PMID: 35957532 DOI: 10.1016/j.molp.2022.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 05/13/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
During adaptive radiation, mitochondria have co-evolved with their hosts, leading to gain or loss of subunits and assembly factors of respiratory complexes. Plant mitochondrial complex I harbors ∼40 nuclear- and 9 mitochondrial-encoded subunits, and is formed by stepwise assembly during which different intermediates are integrated via various assembly factors. In mammals, the mitochondrial complex I intermediate assembly (MCIA) complex is required for building the membrane arm module. However, plants have lost almost all of the MCIA complex components, giving rise to the hypothesis that plants follow an ancestral pathway to assemble the membrane arm subunits. Here, we characterize a maize crumpled seed mutant, crk1, and reveal by map-based cloning that CRK1 encodes an ortholog of human complex I assembly factor 1, zNDUFAF1, the only evolutionarily conserved MCIA subunit in plants. zNDUFAF1 is localized in the mitochondria and accumulates in two intermediate complexes that contain complex I membrane arm subunits. Disruption of zNDUFAF1 results in severe defects in complex I assembly and activity, a cellular bioenergetic shift to aerobic glycolysis, and mitochondrial vacuolation. Moreover, we found that zNDUFAF1, the putative mitochondrial import inner membrane translocase ZmTIM17-1, and the isovaleryl-coenzyme A dehydrogenase ZmIVD1 interact each other, and could be co-precipitated from the mitochondria and co-migrate in the same assembly intermediates. Knockout of either ZmTIM17-1 or ZmIVD1 could lead to the significantly reduced complex I stability and activity as well as defective seeds. These results suggest that zNDUFAF1, ZmTIM17-1 and ZmIVD1 probably form an MCIA-like complex that is essential for the biogenesis of mitochondrial complex I and seed development in maize. Our findings also imply that plants and mammals recruit MCIA subunits independently for mitochondrial complex I assembly, highlighting the importance of parallel evolution in mitochondria adaptation to their hosts.
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Affiliation(s)
- Gang Wang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yongyan Wang
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Jiacheng Ni
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Rongrong Li
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Fengling Zhu
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Ruyin Wang
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Qiuzhen Tian
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Qingwen Shen
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Qinghua Yang
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Jihua Tang
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China; The Shennong Laboratory, Zhengzhou, Henan 450002, China
| | - Monika W Murcha
- School of Molecular Sciences & The ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA 6009, Australia
| | - Guifeng Wang
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China.
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7
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Addition of Conductive Materials to Support Syntrophic Microorganisms in Anaerobic Digestion. FERMENTATION-BASEL 2022. [DOI: 10.3390/fermentation8080354] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Syntrophy and interspecies electron transfer among different microbial groups occurs in anaerobic digestion, and many papers recently reported their positive effect on biogas and methane production. In this paper, we present the results on the effect of conductive material, i.e., graphene, PAC and biochar addition in 3.5 L batch experiments, analyzing the biogas production curve. A peculiar curve pattern occurred in the presence of conductive materials. Compared to the respective controls, the addition of graphene produced a biogas surplus of 33%, PAC 20% and biochar 8%. Microbial community molecular analysis showed that syntrophic microorganisms present in the inoculum were stimulated by the conductive material addition. Graphene also appears to promote an interspecies electron transfer between Geobacter sp. and ca. Methanofastidiosum. This paper contributes to the understanding of the DIET-related microbial community dynamic in the presence of graphene and PAC, which could be exploited to optimize biogas and methane production in real-scale applications.
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8
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ATP synthesis in an ancient ATP synthase at low driving forces. Proc Natl Acad Sci U S A 2022; 119:e2201921119. [PMID: 35512103 DOI: 10.1073/pnas.2201921119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
SignificanceThe ATP synthases of many anaerobic archaea have an unusual motor subunit c that otherwise is only found in eukaryotic V1VO ATPases. The evolutionary switch from synthase to hydrolase is thought to be caused by a doubling of the rotor subunit c, followed by a loss of the ion binding site. By purification and reconstitution of an ATP synthase with a V-type c subunit, we have unequivocally demonstrated, against expectations, the capability of such an enzyme to synthesize ATP at physiological relevant driving forces of 90 to 150 mV. This is the long-awaited answer to an eminent question in microbial energetics and physiology, especially for life near the thermodynamic limit of ATP synthesis.
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9
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Williams TJ, Allen MA, Panwar P, Cavicchioli R. Into the darkness: The ecologies of novel 'microbial dark matter' phyla in an Antarctic lake. Environ Microbiol 2022; 24:2576-2603. [PMID: 35466505 PMCID: PMC9324843 DOI: 10.1111/1462-2920.16026] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/18/2022] [Accepted: 04/20/2022] [Indexed: 11/29/2022]
Abstract
Uncultivated microbial clades ("microbial dark matter") are inferred to play important, but uncharacterized roles in nutrient cycling. Using Antarctic lake (Ace Lake, Vestfold Hills) metagenomes, 12 metagenome-assembled genomes (MAGs; 88-100% complete) were generated for four "dark matter" phyla: six MAGs from Candidatus Auribacterota (= Aureabacteria, SURF-CP-2), inferred to be hydrogen- and sulfide-producing fermentative heterotrophs, with individual MAGs encoding bacterial microcompartments (BMCs), gas vesicles, and type IV pili; one MAG (100% complete) from Candidatus Hinthialibacterota (= OLB16), inferred to be a facultative anaerobe capable of dissimilatory nitrate reduction to ammonia, specialized for mineralization of complex organic matter (e.g., sulfated polysaccharides), and encoding BMCs, flagella, and Tad pili; three MAGs from Candidatus Electryoneota (= AABM5-125-24), previously reported to include facultative anaerobes capable of dissimilatory sulfate reduction, and here inferred to perform sulfite oxidation, reverse tricarboxylic acid cycle for autotrophy, and possess numerous proteolytic enzymes; two MAGs from Candidatus Lernaellota (= FEN-1099), inferred to be capable of formate oxidation, amino acid fermentation, and possess numerous enzymes for protein and polysaccharide degradation. The presence of 16S rRNA gene sequences in public metagenome datasets (88-100% identity) suggests these "dark matter" phyla contribute to sulfur cycling, degradation of complex organic matter, ammonification and/or chemolithoautrophic CO2 fixation in diverse global environments. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Timothy J Williams
- School of Biotechnology and Biomolecular Sciences UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Michelle A Allen
- School of Biotechnology and Biomolecular Sciences UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Pratibha Panwar
- School of Biotechnology and Biomolecular Sciences UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Ricardo Cavicchioli
- School of Biotechnology and Biomolecular Sciences UNSW Sydney, Sydney, New South Wales, 2052, Australia
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10
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Manoj KM, Bazhin NM, Tamagawa H, Jaeken L, Parashar A. The physiological role of complex V in ATP synthesis: Murzyme functioning is viable whereas rotary conformation change model is untenable. J Biomol Struct Dyn 2022; 41:3993-4012. [PMID: 35394896 DOI: 10.1080/07391102.2022.2060307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Complex V or FoF1-ATPase is a multimeric protein found in bioenergetic membranes of cells and organelles like mitochondria/chloroplasts. The popular perception on Complex V deems it as a reversible molecular motor, working bi-directionally (breaking or making ATP) via a conformation-change based chemiosmotic rotary ATP synthesis (CRAS) mechanism, driven by proton-gradients or trans-membrane potential (TMP). In continuance of our pursuits against the CRAS model of cellular bioenergetics, herein we demonstrate the validity of the murburn model based in diffusible reactive (oxygen) species (DRS/DROS). Supported by new in silico derived data (that there are ∼12 adenosine nucleotide binding sites on the F1 bulb and not merely 3 sites, as perceived earlier), available structural information, known experimental observations, and thermodynamic/kinetic considerations (that de-solvation of protons from hydronium ions is facile), we deduce that Complex V serves as a physiological chemostat and a murzyme (enzyme working via murburn scheme, employing DRS). That is- Complex V uses ATP (via consumption at ε or proteins of F1 module) as a Michaelis-Menten substrate to serve as a pH-stat by inletting protons via the c-ring of Fo module. Physiologically, Complex V also functions as a murzyme by presenting ADP/Pi (or their reaction intermediates) on the αβ bulb, thereby enabling greater opportunities for DRS/proton-assisted ATP formation. Thus, the murburn paradigm succeeds the CRAS hypothesis for explaining the role of oxygen in mitochondrial physiologies of oxidative phosphorylation, thermogenesis, TMP and homeostasis.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Kelath Murali Manoj
- Biochemistry Department, Satyamjayatu: The Science & Ethics Foundation, Palakkad, Kerala, India
| | - Nikolai Mikhailovich Bazhin
- Environmental Chemistry Department, Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk, Russia
| | | | - Laurent Jaeken
- Industrial Sciences and Technology, Karel de Grote University College, Antwerp University Association, Hoboken, Belgium
| | - Abhinav Parashar
- Biochemistry Department, Satyamjayatu: The Science & Ethics Foundation, Palakkad, Kerala, India
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11
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Solchaga JI, Busalmen JP, Nercessian D. Unraveling Anaerobic Metabolisms in a Hypersaline Sediment. Front Microbiol 2022; 13:811432. [PMID: 35369499 PMCID: PMC8966722 DOI: 10.3389/fmicb.2022.811432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 01/31/2022] [Indexed: 11/13/2022] Open
Abstract
The knowledge on the microbial diversity inhabiting hypersaline sediments is still limited. In particular, existing data about anaerobic hypersaline archaea and bacteria are scarce and refer to a limited number of genera. The approach to obtain existing information has been almost exclusively attempting to grow every organism in axenic culture on the selected electron acceptor with a variety of electron donors. Here, a different approach has been used to interrogate the microbial community of submerged hypersaline sediment of Salitral Negro, Argentina, aiming at enriching consortia performing anaerobic respiration of different electron acceptor compounds, in which ecological associations can maximize the possibilities of successful growth. Growth of consortia was demonstrated on all offered electron acceptors, including fumarate, nitrate, sulfate, thiosulfate, dimethyl sulfoxide, and a polarized electrode. Halorubrum and Haloarcula representatives are here shown for the first time growing on lactate, using fumarate or a polarized electrode as the electron acceptor; in addition, they are shown also growing in sulfate-reducing consortia. Halorubrum representatives are for the first time shown to be growing in nitrate-reducing consortia, probably thanks to reduction of N2O produced by other consortium members. Fumarate respiration is indeed shown for the first time supporting growth of Halanaeroarchaeum and Halorhabdus belonging to the archaea, as well as growth of Halanaerobium, Halanaerobaculum, Sporohalobacter, and Acetohalobium belonging to the bacteria. Finally, evidence is presented suggesting growth of nanohaloarchaea in anaerobic conditions.
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Affiliation(s)
- Juan Ignacio Solchaga
- Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata - CONICET, Mar del Plata, Argentina
| | - Juan Pablo Busalmen
- Laboratorio de Bioelectroquímica, INTEMA - CONICET, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - Débora Nercessian
- Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata - CONICET, Mar del Plata, Argentina
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12
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Exploring the Distinct Distribution of Archaeal Communities in Sites Contaminated with Explosives. Biomolecules 2022; 12:biom12040489. [PMID: 35454078 PMCID: PMC9028785 DOI: 10.3390/biom12040489] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/24/2021] [Accepted: 12/30/2021] [Indexed: 01/25/2023] Open
Abstract
Most of the research on bioremediation and estimation of microbial diversity in waste contaminated sites is focused on the domain Bacteria, whereas details on the relevance of Archaea are still lacking. The present study examined the archaeal diversity and predicted metabolic pathways in two discrete sites (SITE1 and SITE2) contaminated with explosives (RDX and HMX) by amplicon-targeted sequencing of 16S rRNA genes. In total, 14 soil samples were processed, and 35,758 OTUs were observed, among which 981 OTUs were classified as Archaea, representing ~2.7% of the total microbial diversity in our samples. The majority of OTUs belonged to phyla Euryarchaeota (~49%), Crenarchaeota (~24%), and Thaumarchaeota (~23%), while the remaining (~4%) OTUs were affiliated to Candidatus Parvarchaeota, Candidatus Aenigmarchaeota, and Candidatus Diapherotrites. The comparative studies between explosives contaminated and agricultural soil samples (with no history of explosives contamination) displayed significant differences between the compositions of the archaeal communities. Further, the metabolic pathways pertaining to xenobiotic degradation were presumably more abundant in the contaminated sites. Our data provide a first comprehensive report of archaeal communities in explosives contaminated sites and their putative degradation role in such ecosystems which have been as yet unexplored.
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13
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Puig-Castellví F, Midoux C, Guenne A, Conteau D, Franchi O, Bureau C, Madigou C, Jouan-Rimbaud Bouveresse D, Kroff P, Mazéas L, Rutledge DN, Gaval G, Chapleur O. Metataxonomics, metagenomics and metabolomics analysis of the influence of temperature modification in full-scale anaerobic digesters. BIORESOURCE TECHNOLOGY 2022; 346:126612. [PMID: 34954354 DOI: 10.1016/j.biortech.2021.126612] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 12/17/2021] [Accepted: 12/18/2021] [Indexed: 06/14/2023]
Abstract
Full-scale anaerobic digesters' performance is regulated by modifying their operational conditions, but little is known about how these modifications affect their microbiome. In this work, we monitored two originally mesophilic (35 °C) full-scale anaerobic digesters during 476 days. One digester was submitted to sub-mesophilic (25 °C) conditions between days 123 and 373. We characterized the effect of temperature modification using a multi-omics (metataxonomics, metagenomics, and metabolomics) approach. The metataxonomics and metagenomics results revealed that the lower temperature allowed a substantial increase of the sub-dominant bacterial population, destabilizing the microbial community equilibrium and reducing the biogas production. After restoring the initial mesophilic temperature, the bacterial community manifested resilience in terms of microbial structure and functional activity. The metabolomic signature of the sub-mesophilic acclimation was characterized by a rise of amino acids and short peptides, suggesting a protein degradation activity not directed towards biogas production.
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Affiliation(s)
- Francesc Puig-Castellví
- Université Paris-Saclay, INRAE, AgroParisTech, UMR SayFood, 75005 Paris, France; Université Paris-Saclay, INRAE, PRocédés biOtechnologiques au Service de l'Environnement, 92160 Antony, France
| | - Cédric Midoux
- Université Paris-Saclay, INRAE, PRocédés biOtechnologiques au Service de l'Environnement, 92160 Antony, France; Université Paris-Saclay, INRAE, MaIAGE, 78350, Jouy-en-Josas, France; Université Paris-Saclay, INRAE, BioinfOmics, MIGALE bioinformatics facility, 78350, Jouy-en-Josas, France
| | - Angéline Guenne
- Université Paris-Saclay, INRAE, PRocédés biOtechnologiques au Service de l'Environnement, 92160 Antony, France
| | | | - Oscar Franchi
- Université Paris-Saclay, INRAE, PRocédés biOtechnologiques au Service de l'Environnement, 92160 Antony, France; Universidad Adolfo Ibanez, Facultad de ingeniería y ciencias, 2520000 Viña del mar, Chile
| | - Chrystelle Bureau
- Université Paris-Saclay, INRAE, PRocédés biOtechnologiques au Service de l'Environnement, 92160 Antony, France
| | - Céline Madigou
- Université Paris-Saclay, INRAE, PRocédés biOtechnologiques au Service de l'Environnement, 92160 Antony, France
| | | | | | - Laurent Mazéas
- Université Paris-Saclay, INRAE, PRocédés biOtechnologiques au Service de l'Environnement, 92160 Antony, France
| | - Douglas N Rutledge
- Université Paris-Saclay, INRAE, AgroParisTech, UMR SayFood, 75005 Paris, France; National Wine and Grape Industry Centre, Charles Sturt University, 2650 Wagga Wagga, Australia
| | | | - Olivier Chapleur
- Université Paris-Saclay, INRAE, PRocédés biOtechnologiques au Service de l'Environnement, 92160 Antony, France.
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14
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Liman GLS, Stettler ME, Santangelo TJ. Transformation Techniques for the Anaerobic Hyperthermophile Thermococcus kodakarensis. Methods Mol Biol 2022; 2522:87-104. [PMID: 36125744 PMCID: PMC10026556 DOI: 10.1007/978-1-0716-2445-6_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Genetic manipulation is an essential tool to investigate complex microbiological phenomena. In this chapter we describe the techniques required to transform the model hyperthermophilic, anaerobic archaeon Thermococcus kodakarensis. T. kodakarensis can support two modes of genetic manipulation, dependent either on homologous recombination into the genome or through retention of autonomously replicating plasmids. The robust genetic system developed in T. kodakarensis offers a variety of selectable and counterselectable markers for complex, accurate and iterative genetic manipulations offering greater flexibility to probe gene function in vivo.
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Affiliation(s)
- Geraldy L S Liman
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Meghan E Stettler
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Thomas J Santangelo
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA.
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15
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Mühlbauer ME, Gamiz-Hernandez AP, Kaila VRI. Functional Dynamics of an Ancient Membrane-Bound Hydrogenase. J Am Chem Soc 2021; 143:20873-20883. [PMID: 34846879 PMCID: PMC8679088 DOI: 10.1021/jacs.1c09356] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
![]()
The membrane-bound
hydrogenase (Mbh) is a redox-driven Na+/H+ transporter
that employs the energy from hydrogen
gas (H2) production to catalyze proton pumping and Na+/H+ exchange across cytoplasmic membranes of archaea.
Despite a recently resolved structure of this ancient energy-transducing
enzyme [Yu et al. Cell2018, 173, 1636–1649], the molecular principles of its
redox-driven ion-transport mechanism remain puzzling and of major
interest for understanding bioenergetic principles of early cells.
Here we use atomistic molecular dynamics (MD) simulations in combination
with data clustering methods and quantum chemical calculations to
probe principles underlying proton reduction as well as proton and
sodium transport in Mbh from the hyperthermophilic archaeon Pyrococcus furiosus. We identify putative Na+ binding sites and proton pathways leading across the membrane
and to the NiFe-active center as well as conformational changes that
regulate ion uptake. We suggest that Na+ binding and protonation
changes at a putative ion-binding site couple to proton transfer across
the antiporter-like MbhH subunit by modulating the conformational
state of a conserved ion pair at the subunit interface. Our findings
illustrate conserved coupling principles within the complex I superfamily
and provide functional insight into archaeal energy transduction mechanisms.
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Affiliation(s)
- Max E Mühlbauer
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden.,Department of Chemistry, Technical University of Munich, Lichtenbergstraße 4, 85748 Garching, Germany
| | - Ana P Gamiz-Hernandez
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - Ville R I Kaila
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden.,Department of Chemistry, Technical University of Munich, Lichtenbergstraße 4, 85748 Garching, Germany
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16
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Williams TJ, Allen MA, Berengut JF, Cavicchioli R. Shedding Light on Microbial "Dark Matter": Insights Into Novel Cloacimonadota and Omnitrophota From an Antarctic Lake. Front Microbiol 2021; 12:741077. [PMID: 34707591 PMCID: PMC8542988 DOI: 10.3389/fmicb.2021.741077] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 09/13/2021] [Indexed: 11/13/2022] Open
Abstract
The potential metabolism and ecological roles of many microbial taxa remain unknown because insufficient genomic data are available to assess their functional potential. Two such microbial "dark matter" taxa are the Candidatus bacterial phyla Cloacimonadota and Omnitrophota, both of which have been identified in global anoxic environments, including (but not limited to) organic-carbon-rich lakes. Using 24 metagenome-assembled genomes (MAGs) obtained from an Antarctic lake (Ace Lake, Vestfold Hills), novel lineages and novel metabolic traits were identified for both phyla. The Cloacimonadota MAGs exhibited a capacity for carbon fixation using the reverse tricarboxylic acid cycle driven by oxidation of hydrogen and sulfur. Certain Cloacimonadota MAGs encoded proteins that possess dockerin and cohesin domains, which is consistent with the assembly of extracellular cellulosome-like structures that are used for degradation of polypeptides and polysaccharides. The Omnitrophota MAGs represented phylogenetically diverse taxa that were predicted to possess a strong biosynthetic capacity for amino acids, nucleosides, fatty acids, and essential cofactors. All of the Omnitrophota were inferred to be obligate fermentative heterotrophs that utilize a relatively narrow range of organic compounds, have an incomplete tricarboxylic acid cycle, and possess a single hydrogenase gene important for achieving redox balance in the cell. We reason that both Cloacimonadota and Omnitrophota form metabolic interactions with hydrogen-consuming partners (methanogens and Desulfobacterota, respectively) and, therefore, occupy specific niches in Ace Lake.
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Affiliation(s)
- Timothy J Williams
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, NSW, Australia
| | - Michelle A Allen
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, NSW, Australia
| | - Jonathan F Berengut
- EMBL Australia Node for Single Molecule Science, School of Medical Sciences, UNSW Sydney, Kensington, NSW, Australia
| | - Ricardo Cavicchioli
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, NSW, Australia
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17
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Spontaneous assembly of redox-active iron-sulfur clusters at low concentrations of cysteine. Nat Commun 2021; 12:5925. [PMID: 34635654 PMCID: PMC8505563 DOI: 10.1038/s41467-021-26158-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 09/21/2021] [Indexed: 12/12/2022] Open
Abstract
Iron-sulfur (FeS) proteins are ancient and fundamental to life, being involved in electron transfer and CO2 fixation. FeS clusters have structures similar to the unit-cell of FeS minerals such as greigite, found in hydrothermal systems linked with the origin of life. However, the prebiotic pathway from mineral surfaces to biological clusters is unknown. Here we show that FeS clusters form spontaneously through interactions of inorganic Fe2+/Fe3+ and S2- with micromolar concentrations of the amino acid cysteine in water at alkaline pH. Bicarbonate ions stabilize the clusters and even promote cluster formation alone at concentrations >10 mM, probably through salting-out effects. We demonstrate robust, concentration-dependent formation of [4Fe4S], [2Fe2S] and mononuclear iron clusters using UV-Vis spectroscopy, 57Fe-Mössbauer spectroscopy and 1H-NMR. Cyclic voltammetry shows that the clusters are redox-active. Our findings reveal that the structures responsible for biological electron transfer and CO2 reduction could have formed spontaneously from monomers at the origin of life.
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18
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Archaea: An Agro-Ecological Perspective. Curr Microbiol 2021; 78:2510-2521. [PMID: 34019119 DOI: 10.1007/s00284-021-02537-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 05/05/2021] [Indexed: 10/21/2022]
Abstract
Microorganisms inhabiting bulk soil and rhizosphere play an important role in soil biogeochemical cycles leading to enhanced plant growth and productivity. In this context, the role of bacteria is well established, however, not much reports are available about the role archaea plays in this regard. Literature suggests that archaea also play a greater role in nutrient cycling of carbon, nitrogen, sulfur, and other minerals, possess various plant growth promoting attributes, and can impart tolerance to various abiotic stresses (especially osmotic and oxidative) in areas of high salinity, low and high temperatures and hydrogen ion concentrations. Thermoacidophilic archaea have been found to potentially involve in bioleaching of mineral ores and bioremediation of chemical pollutants and aromatic compounds. Looking at immense potential of archaea in promoting plant growth, alleviating abiotic stresses, and remediating contaminated sites, detailed studies are required to establish their role in different ecological processes, and their interactions in rhizosphere with plant and other microflora (bacteria and fungi) in different ecosystems. In this review, a brief discussion on archaea from the agro-ecological point of view is presented.
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19
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Yu H, Schut GJ, Haja DK, Adams MWW, Li H. Evolution of complex I-like respiratory complexes. J Biol Chem 2021; 296:100740. [PMID: 33957129 PMCID: PMC8165549 DOI: 10.1016/j.jbc.2021.100740] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 04/28/2021] [Accepted: 04/30/2021] [Indexed: 11/06/2022] Open
Abstract
The modern-day respiratory complex I shares a common ancestor with the membrane-bound hydrogenase (MBH) and membrane-bound sulfane sulfur reductase (MBS). MBH and MBS use protons and sulfur as their respective electron sinks, which helped to conserve energy during early life in the Proterozoic era when the Earth's atmosphere was low in oxygen. MBH and MBS likely evolved from an integration of an ancestral, membrane-embedded, multiple resistance and pH antiporter and a soluble redox-active module encompassing a [NiFe] hydrogenase. In this review, we discuss how the structures of MBH, MBS, multiple resistance and pH, photosynthetic NADH dehydrogenase-like complex type-1, and complex I, which have been determined recently, thanks to the advent of high-resolution cryo-EM, have significantly improved our understanding of the catalytic reaction mechanisms and the evolutionary relationships of the respiratory complexes.
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Affiliation(s)
- Hongjun Yu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Gerrit J Schut
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Domink K Haja
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Michael W W Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA.
| | - Huilin Li
- Department of Structural Biology, Van Andel Institute, Grand Rapids, Michigan, USA.
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20
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Calisto F, Sousa FM, Sena FV, Refojo PN, Pereira MM. Mechanisms of Energy Transduction by Charge Translocating Membrane Proteins. Chem Rev 2021; 121:1804-1844. [PMID: 33398986 DOI: 10.1021/acs.chemrev.0c00830] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Life relies on the constant exchange of different forms of energy, i.e., on energy transduction. Therefore, organisms have evolved in a way to be able to harvest the energy made available by external sources (such as light or chemical compounds) and convert these into biological useable energy forms, such as the transmembrane difference of electrochemical potential (Δμ̃). Membrane proteins contribute to the establishment of Δμ̃ by coupling exergonic catalytic reactions to the translocation of charges (electrons/ions) across the membrane. Irrespectively of the energy source and consequent type of reaction, all charge-translocating proteins follow two molecular coupling mechanisms: direct- or indirect-coupling, depending on whether the translocated charge is involved in the driving reaction. In this review, we explore these two coupling mechanisms by thoroughly examining the different types of charge-translocating membrane proteins. For each protein, we analyze the respective reaction thermodynamics, electron transfer/catalytic processes, charge-translocating pathways, and ion/substrate stoichiometries.
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Affiliation(s)
- Filipa Calisto
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal.,BioISI-Biosystems & Integrative Sciences Institute, University of Lisboa, Faculty of Sciences, Campo Grande, 1749-016 Lisboa, Portugal
| | - Filipe M Sousa
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal.,BioISI-Biosystems & Integrative Sciences Institute, University of Lisboa, Faculty of Sciences, Campo Grande, 1749-016 Lisboa, Portugal
| | - Filipa V Sena
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal.,BioISI-Biosystems & Integrative Sciences Institute, University of Lisboa, Faculty of Sciences, Campo Grande, 1749-016 Lisboa, Portugal
| | - Patricia N Refojo
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal
| | - Manuela M Pereira
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal.,BioISI-Biosystems & Integrative Sciences Institute, University of Lisboa, Faculty of Sciences, Campo Grande, 1749-016 Lisboa, Portugal
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21
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Energy Conservation in the Acetogenic Bacterium Clostridium aceticum. Microorganisms 2021; 9:microorganisms9020258. [PMID: 33513854 PMCID: PMC7911925 DOI: 10.3390/microorganisms9020258] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/18/2021] [Accepted: 01/20/2021] [Indexed: 12/13/2022] Open
Abstract
In times of global warming caused by the extensive use of fossil fuels, the need to capture gaseous carbon compounds is growing bigger. Several groups of microorganisms can fix the greenhouse gas CO2. Out of these, acetogenic bacteria are role models in their ability to reduce CO2 with hydrogen to acetate, which makes acetogens prime candidates for genetic modification towards biotechnological production of value-added compounds from CO2, such as biofuels. However, growth of acetogens on gaseous substrates is strongly energy-limited, and successful metabolic engineering requires a detailed knowledge of the bioenergetics. In 1939, Clostridium aceticum was the first acetogen to be described. A recent genomic study revealed that this organism contains cytochromes and therefore may use a proton gradient in its respiratory chain. We have followed up these studies and will present data that C. aceticum does not use a H+ but a Na+ gradient for ATP synthesis, established by a Na+-Rnf. Experimental data and in silico analyses enabled us to propose the biochemistry and bioenergetics of acetogenesis from H2 + CO2 in C. aceticum.
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22
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Westphal L, Litty D, Müller V. Functional production of an archaeal ATP synthase with a V-type c subunit in Escherichia coli. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148378. [PMID: 33460587 DOI: 10.1016/j.bbabio.2021.148378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 12/18/2020] [Accepted: 01/09/2021] [Indexed: 11/18/2022]
Abstract
ATP synthases are the key elements of cellular bioenergetics and present in any life form and the overall structure and function of this rotary energy converter is conserved in all domains of life. However, ancestral microbes, the archaea, have a unique and huge diversity in the size and number of ion-binding sites in their membrane-embedded rotor subunit c. Due to the harsh conditions for ATP synthesis in these life forms it has never been possible to address the consequences of these unusual c subunits for ATP synthesis. Recently, we have found a Na+-dependent archaeal ATP synthase with a V-type c subunit in a mesophilic bacterium and here, we have cloned and expressed the genes in the ATP synthase-negative strain Escherichia coli DK8. The enzyme was present in membranes of E. coli DK8 and catalyzed ATP hydrolysis with a rate of 35 nmol·min-1·mg protein-1. Inverted membrane vesicles of this strain were then checked for their ability to synthesize ATP. Indeed, ATP was synthesized driven by NADH oxidation despite the V-type c subunit. ATP synthesis was dependent on Na+ and inhibited by ionophores. Most importantly, ATPase activity was inhibited by DCCD and this inhibition was relieved by addition of Na+, indicating a functional coupling of the F1 and FO domains, a prerequisite for studies on structure-function relationship. A first step in this direction was the exchange of a conserved arginine (Arg530) in the FO motor subunit a which led to loss of ATP synthesis whereas ATP hydrolysis was retained.
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Affiliation(s)
- Lars Westphal
- Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe Universität Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Dennis Litty
- Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe Universität Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Volker Müller
- Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe Universität Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany.
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23
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Niu M, Zhou F, Yang Y, Sun Y, Zhu T, Shen F. Abundance and composition of airborne archaea during springtime mixed dust and haze periods in Beijing, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 752:141641. [PMID: 32892037 DOI: 10.1016/j.scitotenv.2020.141641] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/09/2020] [Accepted: 08/09/2020] [Indexed: 05/21/2023]
Abstract
Archaea have an important role in the elemental biogeochemical cycle and human health. However, characteristics of airborne archaea affected by anthropogenic and natural processes are unclear. In this study, we investigated the abundance, structures, influencing factors and assembly processes of the archaeal communities in the air samples collected from Beijing in springtime using quantitative polymerase chain reaction (qPCR), high-throughput sequencing technology and statistical analysis. The concentrations of airborne archaea ranged from 101 to 103 copies m-3 (455 ± 211 copies m-3), accounting for 0.67% of the total prokaryote (sum of archaea and bacteria). An increase in airborne archaea was seen when the air quality shifted from clean to slightly polluted conditions. Sandstorm dust imported a large number of archaea to the local atmosphere. Euryarchaeota, Thaumarchaeota and Crenarchaeota were the dominant phyla, revealing the primary role of soil in releasing archaea to the ambient environment. Dispersal-related neutral processes play an important role in shaping the structure of airborne archaeal assembly. Of all phyla, methanogenic Euryarchaeota were most abundant in the air parcels come from the south of Beijing. Air masses from the west of Beijing, which brought sandstorm to Beijing, carried large amounts of ammonia oxidizing archaea Nitrososphaera. The results demonstrate the importance of air mass sources and local weather conditions in shaping the local airborne archaea community.
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Affiliation(s)
- Mutong Niu
- School of Space and Environment, Beihang University, Beijing 102206, China.
| | - Feng Zhou
- School of Space and Environment, Beihang University, Beijing 102206, China.
| | - Yi Yang
- School of Space and Environment, Beihang University, Beijing 102206, China.
| | - Ye Sun
- School of Space and Environment, Beihang University, Beijing 102206, China.
| | - Tianle Zhu
- School of Space and Environment, Beihang University, Beijing 102206, China.
| | - Fangxia Shen
- School of Space and Environment, Beihang University, Beijing 102206, China.
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24
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Comprehensive Bioenergetic Evaluation of Microbial Pathway Variants in Syntrophic Propionate Oxidation. mSystems 2020; 5:5/6/e00814-20. [PMID: 33293404 PMCID: PMC7743110 DOI: 10.1128/msystems.00814-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this work, an original methodology was developed that quantifies bioenergetically and physiologically feasible net ATP yields for large numbers of microbial metabolic pathways and their variants under different conditions. All variants are evaluated, which ensures global optimality in finding the pathway variant(s) leading to the highest ATP yield. In this work, a systematic methodology was developed (based on known biochemistry, physiology, and bioenergetics) for the automated feasibility evaluation and net ATP yield quantification of large sets of pathway variants. Possible pathway variants differ in their intermediate metabolites, in which electron carriers are involved, in which steps are consuming/producing ATP, and in which steps are coupled to (and to how many) proton (or its equivalent) translocations. A pathway variant is deemed feasible, under a given set of physiological and environmental conditions, only if all pathway reaction steps have nonpositive Gibbs energy changes and if all the metabolite concentrations remain within an acceptable physiological range (10−6 to 10−2 M). The complete understanding of syntrophic propionate oxidation remains elusive due to uncertainties in pathways and the mechanisms for interspecies electron transfer (IET). Several million combinations of pathway variants and parameters/conditions were evaluated for propionate oxidation, providing unprecedented mechanistic insight into its biochemical and bioenergetic landscape. Our results show that, under a scenario of optimum environmental conditions for propionate oxidation, the Smithella pathway yields the most ATP and the methylmalonyl-coenzyme A (CoA) pathways can generate sufficient ATP for growth only under a cyclical pathway configuration with pyruvate. The results under conditions typical of methanogenic environments show that propionate oxidation via the lactate and via the hydroxypropionyl-CoA pathways yield the most ATP. IET between propionate oxidizers and methanogens can proceed either by dissolved hydrogen via the Smithella pathway or by different mechanisms (e.g., formate or direct IET) if other pathways are used. IMPORTANCE In this work, an original methodology was developed that quantifies bioenergetically and physiologically feasible net ATP yields for large numbers of microbial metabolic pathways and their variants under different conditions. All variants are evaluated, which ensures global optimality in finding the pathway variant(s) leading to the highest ATP yield. The methodology is designed to be especially relevant to hypothesize on which microbial pathway variants should be most favored in microbial ecosystems under high selective pressure for efficient metabolic energy conservation. Syntrophic microbial oxidation of propionate to acetate has an extremely small quantity of available energy and requires an extremely high metabolic efficiency to sustain life. Our results bring mechanistic insights into the optimum pathway variants, other metabolic bottlenecks, and the impact of environmental conditions on the ATP yields. Additionally, our results conclude that, as previously reported, under specific conditions, IET mechanisms other than hydrogen must exist to simultaneously sustain the growth of both propionate oxidizers and hydrogenotrophic methanogens.
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25
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Structure of the Dietzia Mrp complex reveals molecular mechanism of this giant bacterial sodium proton pump. Proc Natl Acad Sci U S A 2020; 117:31166-31176. [PMID: 33229520 PMCID: PMC7733839 DOI: 10.1073/pnas.2006276117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Multiple resistance and pH adaptation (Mrp) complexes are the most sophisticated known cation/proton exchangers and are essential for the survival of a vast variety of alkaliphilic and/or halophilic microorganisms. Moreover, this family of antiporters represents the ancestor of cation pumps in nearly all known redox-driven transporter complexes, including the complex I of the respiratory chain. For the Mrp complex, an experimental structure is lacking. We now report the structure of Mrp complex at 3.0-Å resolution solved using the single-particle cryo-EM method. The structure-inspired functional study of Mrp provides detailed information for further biophysical and biochemical investigation of the intriguingly pumping mechanism and physiological functions of this complex, as well as for exploring its potential as a therapeutic drug target. Multiple resistance and pH adaptation (Mrp) complexes are sophisticated cation/proton exchangers found in a vast variety of alkaliphilic and/or halophilic microorganisms, and are critical for their survival in highly challenging environments. This family of antiporters is likely to represent the ancestor of cation pumps found in many redox-driven transporter complexes, including the complex I of the respiratory chain. Here, we present the three-dimensional structure of the Mrp complex from a Dietzia sp. strain solved at 3.0-Å resolution using the single-particle cryoelectron microscopy method. Our structure-based mutagenesis and functional analyses suggest that the substrate translocation pathways for the driving substance protons and the substrate sodium ions are separated in two modules and that symmetry-restrained conformational change underlies the functional cycle of the transporter. Our findings shed light on mechanisms of redox-driven primary active transporters, and explain how driving substances of different electric charges may drive similar transport processes.
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26
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Yu H, Haja DK, Schut GJ, Wu CH, Meng X, Zhao G, Li H, Adams MWW. Structure of the respiratory MBS complex reveals iron-sulfur cluster catalyzed sulfane sulfur reduction in ancient life. Nat Commun 2020; 11:5953. [PMID: 33230146 PMCID: PMC7684303 DOI: 10.1038/s41467-020-19697-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/19/2020] [Indexed: 11/17/2022] Open
Abstract
Modern day aerobic respiration in mitochondria involving complex I converts redox energy into chemical energy and likely evolved from a simple anaerobic system now represented by hydrogen gas-evolving hydrogenase (MBH) where protons are the terminal electron acceptor. Here we present the cryo-EM structure of an early ancestor in the evolution of complex I, the elemental sulfur (S0)-reducing reductase MBS. Three highly conserved protein loops linking cytoplasmic and membrane domains enable scalable energy conversion in all three complexes. MBS contains two proton pumps compared to one in MBH and likely conserves twice the energy. The structure also reveals evolutionary adaptations of MBH that enabled S0 reduction by MBS catalyzed by a site-differentiated iron-sulfur cluster without participation of protons or amino acid residues. This is the simplest mechanism proposed for reduction of inorganic or organic disulfides. It is of fundamental significance in the iron and sulfur-rich volcanic environments of early earth and possibly the origin of life. MBS provides a new perspective on the evolution of modern-day respiratory complexes and of catalysis by biological iron-sulfur clusters. The sulfur-reducing enzyme MBS and the hydrogen-gas evolving MBH are the evolutionary link between the ancestor Mrp antiporter and the mitochondrial respiratory complex I. Here, the authors characterise MBS from the hyperthermophilic archaeon Pyrococcus furiosus, solve its cryo-EM structure and discuss the structural evolution from Mrp to MBH and MBS and to the modern-day complex I.
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Affiliation(s)
- Hongjun Yu
- Structural Biology Program, Van Andel Institute, Grand Rapids, MI, USA.,Department of Biochemistry and Molecular Biology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dominik K Haja
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Gerrit J Schut
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Chang-Hao Wu
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Xing Meng
- Structural Biology Program, Van Andel Institute, Grand Rapids, MI, USA
| | - Gongpu Zhao
- Structural Biology Program, Van Andel Institute, Grand Rapids, MI, USA
| | - Huilin Li
- Structural Biology Program, Van Andel Institute, Grand Rapids, MI, USA.
| | - Michael W W Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA.
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27
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Deka RK, Liu WZ, Norgard MV, Brautigam CA. Biophysical and Biochemical Characterization of TP0037, a d-Lactate Dehydrogenase, Supports an Acetogenic Energy Conservation Pathway in Treponema pallidum. mBio 2020; 11:e02249-20. [PMID: 32963009 PMCID: PMC7512555 DOI: 10.1128/mbio.02249-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 08/18/2020] [Indexed: 12/13/2022] Open
Abstract
A longstanding conundrum in Treponema pallidum biology concerns how the spirochete generates sufficient energy to fulfill its complex pathogenesis processes during human syphilitic infection. For decades, it has been assumed that the bacterium relies solely on glucose catabolism (via glycolysis) for generation of its ATP. However, the organism's robust motility, believed to be essential for human tissue invasion and dissemination, would require abundant ATP likely not provided by the parsimony of glycolysis. As such, additional ATP generation, either via a chemiosmotic gradient, substrate-level phosphorylation, or both, likely exists in T. pallidum Along these lines, we have hypothesized that T. pallidum exploits an acetogenic energy conservation pathway that relies on the redox chemistry of flavins. Central to this hypothesis is the apparent existence in T. pallidum of an acetogenic pathway for the conversion of d-lactate to acetate. Herein we have characterized the structural, biophysical, and biochemical properties of the first enzyme (d-lactate dehydrogenase [d-LDH]; TP0037) predicted in this pathway. Binding and enzymatic studies showed that recombinant TP0037 consumed d-lactate and NAD+ to produce pyruvate and NADH. The crystal structure of TP0037 revealed a fold similar to that of other d-acid dehydrogenases; residues in the cofactor-binding and active sites were homologous to those of other known d-LDHs. The crystal structure and solution biophysical experiments revealed the protein's propensity to dimerize, akin to other d-LDHs. This study is the first to elucidate the enzymatic properties of T. pallidum's d-LDH, thereby providing new compelling evidence for a flavin-dependent acetogenic energy conservation (ATP-generating) pathway in T. pallidumIMPORTANCE Because T. pallidum lacks a Krebs cycle and the capability for oxidative phosphorylation, historically it has been difficult to reconcile how the syphilis spirochete generates sufficient ATP to fulfill its energy needs, particularly for its robust motility, solely from glycolysis. We have postulated the existence in T. pallidum of a flavin-dependent acetogenic energy conservation pathway that would generate additional ATP for T. pallidum bioenergetics. In the proposed acetogenic pathway, first d-lactate would be converted to pyruvate. Pyruvate would then be metabolized to acetate in three additional steps, with ATP being generated via substrate-level phosphorylation. This study provides structural, biochemical, and biophysical evidence for the first T. pallidum enzyme in the pathway (TP0037; d-lactate dehydrogenase) requisite for the conversion of d-lactate to pyruvate. The findings represent the first experimental evidence to support a role for an acetogenic energy conservation pathway that would contribute to nonglycolytic ATP production in T. pallidum.
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Affiliation(s)
- Ranjit K Deka
- Department of Microbiology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Wei Z Liu
- Department of Microbiology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Michael V Norgard
- Department of Microbiology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Chad A Brautigam
- Department of Microbiology, UT Southwestern Medical Center, Dallas, Texas, USA
- Department of Biophysics, UT Southwestern Medical Center, Dallas, Texas, USA
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28
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Collins MP, Forgac M. Regulation and function of V-ATPases in physiology and disease. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183341. [PMID: 32422136 DOI: 10.1016/j.bbamem.2020.183341] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/30/2020] [Accepted: 05/03/2020] [Indexed: 02/07/2023]
Abstract
The vacuolar H+-ATPases (V-ATPases) are essential, ATP-dependent proton pumps present in a variety of eukaryotic cellular membranes. Intracellularly, V-ATPase-dependent acidification functions in such processes as membrane traffic, protein degradation, autophagy and the coupled transport of small molecules. V-ATPases at the plasma membrane of certain specialized cells function in such processes as bone resorption, sperm maturation and urinary acidification. V-ATPases also function in disease processes such as pathogen entry and cancer cell invasiveness, while defects in V-ATPase genes are associated with disorders such as osteopetrosis, renal tubular acidosis and neurodegenerative diseases. This review highlights recent advances in our understanding of V-ATPase structure, mechanism, function and regulation, with an emphasis on the signaling pathways controlling V-ATPase assembly in mammalian cells. The role of V-ATPases in cancer and other human pathologies, and the prospects for therapeutic intervention, are also discussed.
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Affiliation(s)
- Michael P Collins
- Cell, Molecular and Developmental Biology, Tufts University Graduate School of Biomedical Sciences, United States of America
| | - Michael Forgac
- Cell, Molecular and Developmental Biology, Tufts University Graduate School of Biomedical Sciences, United States of America; Dept. of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, United States of America.
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29
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Formate Utilization by the Crenarchaeon Desulfurococcus amylolyticus. Microorganisms 2020; 8:microorganisms8030454. [PMID: 32210133 PMCID: PMC7143981 DOI: 10.3390/microorganisms8030454] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 03/18/2020] [Accepted: 03/20/2020] [Indexed: 12/03/2022] Open
Abstract
Formate is one of the key compounds of the microbial carbon and/or energy metabolism. It owes a significant contribution to various anaerobic syntrophic associations, and may become one of the energy storage compounds of modern energy biotechnology. Microbial growth on formate was demonstrated for different bacteria and archaea, but not yet for species of the archaeal phylum Crenarchaeota. Here, we show that Desulfurococcus amylolyticus DSM 16532, an anaerobic and hyperthermophilic Crenarchaeon, metabolises formate without the production of molecular hydrogen. Growth, substrate uptake, and production kinetics on formate, glucose, and glucose/formate mixtures exhibited similar specific growth rates and similar final cell densities. A whole cell conversion experiment on formate revealed that D. amylolyticus converts formate into carbon dioxide, acetate, citrate, and ethanol. Using bioinformatic analysis, we examined whether one of the currently known and postulated formate utilisation pathways could be operative in D. amylolyticus. This analysis indicated the possibility that D. amylolyticus uses formaldehyde producing enzymes for the assimilation of formate. Therefore, we propose that formate might be assimilated into biomass through formaldehyde dehydrogenase and the oxidative pentose phosphate pathway. These findings shed new light on the metabolic versatility of the archaeal phylum Crenarchaeota.
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30
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Zhou L, Sazanov LA. Structure and conformational plasticity of the intact Thermus thermophilus V/A-type ATPase. Science 2020; 365:365/6455/eaaw9144. [PMID: 31439765 DOI: 10.1126/science.aaw9144] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 07/10/2019] [Indexed: 12/21/2022]
Abstract
V (vacuolar)/A (archaeal)-type adenosine triphosphatases (ATPases), found in archaea and eubacteria, couple ATP hydrolysis or synthesis to proton translocation across the plasma membrane using the rotary-catalysis mechanism. They belong to the V-type ATPase family, which differs from the mitochondrial/chloroplast F-type ATP synthases in overall architecture. We solved cryo-electron microscopy structures of the intact Thermus thermophilus V/A-ATPase, reconstituted into lipid nanodiscs, in three rotational states and two substates. These structures indicate substantial flexibility between V1 and Vo in a working enzyme, which results from mechanical competition between central shaft rotation and resistance from the peripheral stalks. We also describe details of adenosine diphosphate inhibition release, V1-Vo torque transmission, and proton translocation, which are relevant for the entire V-type ATPase family.
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Affiliation(s)
- Long Zhou
- Institute of Science and Technology Austria, Klosterneuberg 3400, Austria
| | - Leonid A Sazanov
- Institute of Science and Technology Austria, Klosterneuberg 3400, Austria.
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31
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Jørgensen BB, Andrén T, Marshall IPG. Sub-seafloor biogeochemical processes and microbial life in the Baltic Sea. Environ Microbiol 2020; 22:1688-1706. [PMID: 31970880 DOI: 10.1111/1462-2920.14920] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/18/2020] [Accepted: 01/21/2020] [Indexed: 01/15/2023]
Abstract
The post-glacial Baltic Sea has experienced extreme changes that are archived today in the deep sediments. IODP Expedition 347 retrieved cores down to 100 m depth and studied the climate history and the deep biosphere. We here review the biogeochemical and microbiological highlights and integrate these with other studies from the Baltic seabed. Cell numbers, endospore abundance and organic matter mineralization rates are extremely high. A 100-fold drop in cell numbers with depth results from a small difference between growth and mortality in the ageing sediment. Evidence for growth derives from a D:L amino acid racemization model, while evidence for mortality derives from the abundance and potential activity of lytic viruses. The deep communities assemble at the bottom of the bioturbated zone from the founding surface community by selection of organisms suited for life under deep sediment conditions. The mean catabolic per-cell rate of microorganisms drops steeply with depth to a life in slow-motion, typical for the deep biosphere. The subsurface life under extreme energy limitation is facilitated by exploitation of recalcitrant substrates, by biochemical protection of nucleic acids and proteins and by repair mechanisms for random mismatches in DNA or damaged amino acids in proteins.
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Affiliation(s)
- Bo Barker Jørgensen
- Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Thomas Andrén
- School of Natural Sciences, Technology and Environmental Studies, Södertörn University, Huddinge, Sweden
| | - Ian P G Marshall
- Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark.,Center for Electromicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
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32
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Litty D, Müller V. A Na + A 1 A O ATP synthase with a V-type c subunit in a mesophilic bacterium. FEBS J 2020; 287:3012-3023. [PMID: 31876375 DOI: 10.1111/febs.15193] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 11/18/2019] [Accepted: 12/22/2019] [Indexed: 01/01/2023]
Abstract
A1 AO ATP synthases with a V-type c subunit have only been found in hyperthermophilic archaea which makes bioenergetic analyses impossible due to the instability of liposomes at high temperatures. A search for a potential archaeal A1 AO ATP synthase with a V-type c subunit in a mesophilic organism revealed an A1 AO ATP synthase cluster in the anaerobic, acetogenic bacterium Eubacterium limosum KIST612. The enzyme was purified to apparent homogeneity from cells grown on methanol to a specific activity of 1.2 U·mg-1 with a yield of 12%. The enzyme contained subunits A, B, C, D, E, F, H, a, and c. Subunit c is predicted to be a typical V-type c subunit with only one ion (Na+ )-binding site. Indeed, ATP hydrolysis was strictly Na+ -dependent. N,N'-dicyclohexylcarbodiimide (DCCD) inhibited ATP hydrolysis, but inhibition was relieved by addition of Na+ . Na+ was shown directly to abolish binding of the fluorescence DCCD derivative, NCD-4, to subunit c, demonstrating a competition of Na+ and DCCD/NCD-4 for a common binding site. After incorporation of the A1 AO ATP synthase into liposomes, ATP-dependent primary transport of 22 Na+ as well as ΔµNa+ -driven ATP synthesis could be demonstrated. The Na+ A1 AO ATP synthase from E. limosum is the first ATP synthase with a V-type c subunit from a mesophilic organism. This will enable future bioenergetic analysis of these unique ATP synthases.
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Affiliation(s)
- Dennis Litty
- Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt/Main, Germany
| | - Volker Müller
- Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt/Main, Germany
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33
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Abstract
Chemiosmosis and substrate-level phosphorylation are the 2 mechanisms employed to form the biological energy currency adenosine triphosphate (ATP). During chemiosmosis, a transmembrane electrochemical ion gradient is harnessed by a rotary ATP synthase to phosphorylate adenosine diphosphate to ATP. In microorganisms, this ion gradient is usually composed of [Formula: see text], but it can also be composed of Na+ Here, we show that the strictly anaerobic rumen bacterium Pseudobutyrivibrio ruminis possesses 2 ATP synthases and 2 distinct respiratory enzymes, the ferredoxin:[Formula: see text] oxidoreductase (Rnf complex) and the energy-converting hydrogenase (Ech complex). In silico analyses revealed that 1 ATP synthase is [Formula: see text]-dependent and the other Na+-dependent, which was validated by biochemical analyses. Rnf and Ech activity was also biochemically identified and investigated in membranes of P. ruminis Furthermore, the physiology of the rumen bacterium and the role of the energy-conserving systems was investigated in dependence of 2 different catabolic pathways (the Embden-Meyerhof-Parnas or the pentose-phosphate pathway) and in dependence of Na+ availability. Growth of P. ruminis was greatly stimulated by Na+, and a combination of physiological, biochemical, and transcriptional analyses revealed the role of the energy conserving systems in P. ruminis under different metabolic scenarios. These data demonstrate the use of a 2-component ion circuit for [Formula: see text] bioenergetics and a 2nd 2-component ion circuit for Na+ bioenergetics in a strictly anaerobic rumen bacterium. In silico analyses infer that these 2 circuits are prevalent in a number of other strictly anaerobic microorganisms.
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34
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Schoelmerich MC, Müller V. Energy-converting hydrogenases: the link between H 2 metabolism and energy conservation. Cell Mol Life Sci 2019; 77:1461-1481. [PMID: 31630229 DOI: 10.1007/s00018-019-03329-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/17/2019] [Accepted: 10/01/2019] [Indexed: 10/25/2022]
Abstract
The reversible interconversion of molecular hydrogen and protons is one of the most ancient microbial metabolic reactions and catalyzed by hydrogenases. A widespread yet largely enigmatic group comprises multisubunit [NiFe] hydrogenases, that directly couple H2 metabolism to the electrochemical ion gradient across the membranes of bacteria and of archaea. These complexes are collectively referred to as energy-converting hydrogenases (Ech), as they reversibly transform redox energy into physicochemical energy. Redox energy is typically provided by a low potential electron donor such as reduced ferredoxin to fuel H2 evolution and the establishment of a transmembrane electrochemical ion gradient ([Formula: see text]). The [Formula: see text] is then utilized by an ATP synthase for energy conservation by generating ATP. This review describes the modular structure/function of Ech complexes, focuses on insights into the energy-converting mechanisms, describes the evolutionary context and delves into the implications of relying on an Ech complex as respiratory enzyme for microbial metabolism.
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Affiliation(s)
- Marie Charlotte Schoelmerich
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany.,Microbiology and Biotechnology, Institute of Plant Sciences and Microbiology, Universität Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany
| | - Volker Müller
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany.
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35
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Mayer F, Enzmann F, Lopez AM, Holtmann D. Performance of different methanogenic species for the microbial electrosynthesis of methane from carbon dioxide. BIORESOURCE TECHNOLOGY 2019; 289:121706. [PMID: 31279320 DOI: 10.1016/j.biortech.2019.121706] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/21/2019] [Accepted: 06/26/2019] [Indexed: 06/09/2023]
Abstract
Microbial electrosynthesis (MES) is a promising technology to convert CO2 and electricity into the biofuel methane using methanogens. Until now, most investigations on electro-methanogenesis are "proof-of-principle" studies. In this paper, different strains were quantitatively compared in regard to final methane concentration, yields based on CO2-conversion, productivities as well as Coulombic efficiencies in order to identify suitable organisms for MES. Methanococcus vannielii, Methanococcus maripaludis, Methanolacinia petrolearia, Methanobacterium congolense, and Methanoculleus submarinus were able to produce methane via MES at -700 mV vs. standard hydrogen electrode (SHE). Beside methane also biological H2 production was detected during MES, which might be due to the involvement of hydrogenases. A direct electron transfer pathway is most likely. Obviously, M. maripaludis is the most resource efficient methane producer in microbial electrosynthesis regarding the methane productivity (8.81 ± 0.51 mmol m-2 d-1) and the Coulombic efficiency (58.9 ± 0.8%).
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Affiliation(s)
- Florian Mayer
- DECHEMA-Forschungsinstitut, Industrielle Biotechnologie, Frankfurt am Main, Germany
| | - Franziska Enzmann
- DECHEMA-Forschungsinstitut, Industrielle Biotechnologie, Frankfurt am Main, Germany
| | | | - Dirk Holtmann
- DECHEMA-Forschungsinstitut, Industrielle Biotechnologie, Frankfurt am Main, Germany.
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36
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Brangulis K, Akopjana I, Petrovskis I, Kazaks A, Jekabsons A, Jaudzems K, Viksna A, Bertins M, Tars K. Structural analysis of Borrelia burgdorferi periplasmic lipoprotein BB0365 involved in Lyme disease infection. FEBS Lett 2019; 594:317-326. [PMID: 31486526 DOI: 10.1002/1873-3468.13594] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/15/2019] [Accepted: 08/28/2019] [Indexed: 11/07/2022]
Abstract
The periplasmic lipoprotein BB0365 of the Lyme disease agent Borrelia burgdorferi is expressed throughout mammalian infection and is essential for all phases of Lyme disease infection; its function, however, remains unknown. In the current study, our structural analysis of BB0365 revealed the same structural fold as that found in the NqrC and RnfG subunits of the NADH:quinone and ferredoxin:NAD+ sodium-translocating oxidoreductase complexes, which points to a potential role for BB0365 as a component of the sodium pump. Additionally, BB0365 coordinated Zn2+ by the His51, His55, His140 residues, and the Zn2+ -binding site indicates that BB0365 could act as a potential metalloenzyme; therefore, this structure narrows down the potential functions of BB0365, an essential protein for B. burgdorferi to cause Lyme disease.
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Affiliation(s)
| | - Inara Akopjana
- Latvian Biomedical Research and Study Centre, Riga, Latvia
| | | | - Andris Kazaks
- Latvian Biomedical Research and Study Centre, Riga, Latvia
| | | | - Kristaps Jaudzems
- Latvian Institute of Organic Synthesis, Riga, Latvia.,Faculty of Chemistry, University of Latvia, Riga, Latvia
| | - Arturs Viksna
- Faculty of Chemistry, University of Latvia, Riga, Latvia
| | - Maris Bertins
- Faculty of Chemistry, University of Latvia, Riga, Latvia
| | - Kaspars Tars
- Latvian Biomedical Research and Study Centre, Riga, Latvia.,Faculty of Biology, University of Latvia, Riga, Latvia
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37
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Fischer MA, Ulbricht A, Neulinger SC, Refai S, Waßmann K, Künzel S, Schmitz RA. Immediate Effects of Ammonia Shock on Transcription and Composition of a Biogas Reactor Microbiome. Front Microbiol 2019; 10:2064. [PMID: 31555248 PMCID: PMC6742706 DOI: 10.3389/fmicb.2019.02064] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 08/21/2019] [Indexed: 12/22/2022] Open
Abstract
The biotechnological process of biogas production from organic material is carried out by a diverse microbial community under anaerobic conditions. However, the complex and sensitive microbial network present in anaerobic degradation of organic material can be disturbed by increased ammonia concentration introduced into the system by protein-rich substrates and imbalanced feeding. Here, we report on a simulated increase of ammonia concentration in a fed batch lab-scale biogas reactor experiment. Two treatment conditions were used simulating total ammonia nitrogen concentrations of 4.9 and 8.0 g/L with four replicate reactors. Each reactor was monitored concerning methane generation and microbial composition using 16S rRNA gene amplicon sequencing, while the transcriptional activity of the overall process was investigated by metatranscriptomic analysis. This allowed investigating the response of the microbial community in terms of species composition and transcriptional activity to a rapid upshift to high ammonia conditions. Clostridia and Methanomicrobiales dominated the microbial community throughout the entire experiment under both experimental conditions, while Methanosarcinales were only present in minor abundance. Transcription analysis demonstrated clostridial dominance with respect to genes encoding for enzymes of the hydrolysis step (cellulase, EC 3.2.1.4) as well as dominance of key genes for enzymes of the methanogenic pathway (methyl-CoM reductase, EC 2.8.4.1; heterodisulfide reductase, EC 1.8.98.1). Upon ammonia shock, the selected marker genes showed significant changes in transcriptional activity. Cellulose hydrolysis as well as methanogenesis were significantly reduced at high ammonia concentrations as indicated by reduced transcription levels of the corresponding genes. Based on these experiments we concluded that, apart from the methanogenic archaea, hydrolytic cellulose-degrading microorganisms are negatively affected by high ammonia concentrations. Further, Acholeplasma and Erysipelotrichia showed lower abundance under increased ammonia concentrations and thus might serve as indicator species for an earlier detection in order to counteract against ammonia crises.
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Affiliation(s)
- Martin A. Fischer
- Department of Biology, Institute of General Microbiology, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Andrea Ulbricht
- Department of Biology, Institute of General Microbiology, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Sven C. Neulinger
- Department of Biology, Institute of General Microbiology, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Sarah Refai
- Department of Biology, Institut für Mikrobiologie und Biotechnologie, University Bonn, Bonn, Germany
| | - Kati Waßmann
- Department of Biology, Institut für Mikrobiologie und Biotechnologie, University Bonn, Bonn, Germany
| | - Sven Künzel
- Department for Evolutionary Genetics, Max-Planck-Institute for Evolutionary Biology, Plön, Germany
| | - Ruth A. Schmitz
- Department of Biology, Institute of General Microbiology, Christian-Albrechts-University Kiel, Kiel, Germany
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38
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Lynch TA, Wang Y, van Brunt B, Pacheco D, Janssen PH. Modelling thermodynamic feedback on the metabolism of hydrogenotrophic methanogens. J Theor Biol 2019; 477:14-23. [PMID: 31150665 DOI: 10.1016/j.jtbi.2019.05.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 05/23/2019] [Accepted: 05/28/2019] [Indexed: 11/25/2022]
Abstract
The magnitude of the Gibbs free energy change of the substrate transformation that supports the growth of a microbe is decreased when the concentrations of the substrates are decreased and when the concentrations of the products of metabolism are increased. Microbes require a supply of ATP for cell maintenance and growth, and coupling the transformation of substrates to products with the formation of ATP also decreases the magnitude of the Gibbs free energy change. Here we include these three thermodynamic controllers (substrate and product concentration, and ATP formation) in a model of substrate transformation by hydrogenotrophic methanogens that results in a number of realistic behaviours. First, a threshold for substrate use emerges, below which the methanogen cannot metabolise its substrate. Under this model, microbes that capture more of the Gibbs free energy change from substrate transformation in the form of ATP have greater thresholds for their substrate, in line with observations of actual microbes. Second, an apparent saturation constant emerges that is controlled by the thermodynamics of the reaction. This increases with increasing ATP synthesis per substrate, so that methanogens that conserve more ATP grow faster at higher substrate concentrations, but are less competitive at low substrate concentrations. As a result, simply changing the ATP yield (moles of ATP per mole of substrate) results in methanogens with differing ecological strategies through thermodynamic impacts on their metabolism. Third, end-product inhibition through thermodynamic feedback can limit the growth of microbes, and those that capture more ATP per substrate are limited by smaller product concentrations than those that capture less ATP.
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Affiliation(s)
- T A Lynch
- Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Y Wang
- Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand; AgResearch, Grasslands Research Centre, Palmerston North 4442, New Zealand
| | - B van Brunt
- Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - D Pacheco
- AgResearch, Grasslands Research Centre, Palmerston North 4442, New Zealand
| | - P H Janssen
- AgResearch, Grasslands Research Centre, Palmerston North 4442, New Zealand.
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39
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Uncultured Microbial Phyla Suggest Mechanisms for Multi-Thousand-Year Subsistence in Baltic Sea Sediments. mBio 2019; 10:mBio.02376-18. [PMID: 30992358 PMCID: PMC6469976 DOI: 10.1128/mbio.02376-18] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Much of life on Earth exists in a very slow-growing state, with microbes from deeply buried marine sediments representing an extreme example. These environments are like natural laboratories that have run multi-thousand-year experiments that are impossible to perform in a laboratory. We borrowed some techniques that are commonly used in laboratory experiments and applied them to these natural samples to make hypotheses about how these microbes subsist for so long at low activity. We found that some methods for stabilizing proteins and nucleic acids might be used by many members of the community. We also found evidence for niche differentiation strategies, and possibly cross-feeding, suggesting that even though they are barely growing, complex ecological interactions continue to occur over ultralong timescales. Energy-starved microbes in deep marine sediments subsist at near-zero growth for thousands of years, yet the mechanisms for their subsistence are unknown because no model strains have been cultivated from most of these groups. We investigated Baltic Sea sediments with single-cell genomics, metabolomics, metatranscriptomics, and enzyme assays to identify possible subsistence mechanisms employed by uncultured Atribacteria, Aminicenantes, Actinobacteria group OPB41, Aerophobetes, Chloroflexi, Deltaproteobacteria, Desulfatiglans, Bathyarchaeota, and Euryarchaeota marine group II lineages. Some functions appeared to be shared by multiple lineages, such as trehalose production and NAD+-consuming deacetylation, both of which have been shown to increase cellular life spans in other organisms by stabilizing proteins and nucleic acids, respectively. Other possible subsistence mechanisms differed between lineages, possibly providing them different physiological niches. Enzyme assays and transcripts suggested that Atribacteria and Actinobacteria group OPB41 catabolized sugars, whereas Aminicenantes and Atribacteria catabolized peptides. Metabolite and transcript data suggested that Atribacteria utilized allantoin, possibly as an energetic substrate or chemical protectant, and also possessed energy-efficient sodium pumps. Atribacteria single-cell amplified genomes (SAGs) recruited transcripts for full pathways for the production of all 20 canonical amino acids, and the gene for amino acid exporter YddG was one of their most highly transcribed genes, suggesting that they may benefit from metabolic interdependence with other cells. Subsistence of uncultured phyla in deep subsurface sediments may occur through shared strategies of using chemical protectants for biomolecular stabilization, but also by differentiating into physiological niches and metabolic interdependencies.
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Distinct Physiological Roles of the Three Ferredoxins Encoded in the Hyperthermophilic Archaeon Thermococcus kodakarensis. mBio 2019; 10:mBio.02807-18. [PMID: 30837343 PMCID: PMC6401487 DOI: 10.1128/mbio.02807-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
High-energy electrons liberated during catabolic processes can be exploited for energy-conserving mechanisms. Maximal energy gains demand these valuable electrons be accurately shuttled from electron donor to appropriate electron acceptor. Proteinaceous electron carriers such as ferredoxins offer opportunities to exploit specific ferredoxin partnerships to ensure that electron flux to critical physiological pathways is aligned with maximal energy gains. Most species encode many ferredoxin isoforms, but very little is known about the role of individual ferredoxins in most systems. Our results detail that ferredoxin isoforms make largely unique and distinct protein interactions in vivo and that flux through one ferredoxin often cannot be recovered by flux through a different ferredoxin isoform. The results obtained more broadly suggest that ferredoxin isoforms throughout biological life have evolved not as generic electron shuttles, but rather serve as selective couriers of valuable low-potential electrons from select electron donors to desirable electron acceptors. Control of electron flux is critical in both natural and bioengineered systems to maximize energy gains. Both small molecules and proteins shuttle high-energy, low-potential electrons liberated during catabolism through diverse metabolic landscapes. Ferredoxin (Fd) proteins—an abundant class of Fe-S-containing small proteins—are essential in many species for energy conservation and ATP production strategies. It remains difficult to model electron flow through complicated metabolisms and in systems in which multiple Fd proteins are present. The overlap of activity and/or limitations of electron flux through each Fd can limit physiology and metabolic engineering strategies. Here we establish the interplay, reactivity, and physiological role(s) of the three ferredoxin proteins in the model hyperthermophile Thermococcus kodakarensis. We demonstrate that the three loci encoding known Fds are subject to distinct regulatory mechanisms and that specific Fds are utilized to shuttle electrons to separate respiratory and energy production complexes during different physiological states. The results obtained argue that unique physiological roles have been established for each Fd and that continued use of T. kodakarensis and related hydrogen-evolving species as bioengineering platforms must account for the distinct Fd partnerships that limit flux to desired electron acceptors. Extrapolating our results more broadly, the retention of multiple Fd isoforms in most species argues that specialized Fd partnerships are likely to influence electron flux throughout biology.
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Hydrogen-based metabolism as an ancestral trait in lineages sibling to the Cyanobacteria. Nat Commun 2019; 10:463. [PMID: 30692531 PMCID: PMC6349859 DOI: 10.1038/s41467-018-08246-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 12/18/2018] [Indexed: 01/06/2023] Open
Abstract
The evolution of aerobic respiration was likely linked to the origins of oxygenic Cyanobacteria. Close phylogenetic neighbors to Cyanobacteria, such as Margulisbacteria (RBX-1 and ZB3), Saganbacteria (WOR-1), Melainabacteria and Sericytochromatia, may constrain the metabolic platform in which aerobic respiration arose. Here, we analyze genomic sequences and predict that sediment-associated Margulisbacteria have a fermentation-based metabolism featuring a variety of hydrogenases, a streamlined nitrogenase, and electron bifurcating complexes involved in cycling of reducing equivalents. The genomes of ocean-associated Margulisbacteria encode an electron transport chain that may support aerobic growth. Some Saganbacteria genomes encode various hydrogenases, and others may be able to use O2 under certain conditions via a putative novel type of heme copper O2 reductase. Similarly, Melainabacteria have diverse energy metabolisms and are capable of fermentation and aerobic or anaerobic respiration. The ancestor of all these groups may have been an anaerobe in which fermentation and H2 metabolism were central metabolic features. The ability to use O2 as a terminal electron acceptor must have been subsequently acquired by these lineages. Most cyanobacteria are oxygenic photoautotrophs, and fermenters under dark anoxic conditions. Here, the authors analyse genomic sequences of related uncultivated bacteria, inferring their metabolic potential, and supporting that their common ancestor was an anaerobe capable of fermentation and H2 metabolism.
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42
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Cossio P, Allegretti M, Mayer F, Müller V, Vonck J, Hummer G. Bayesian inference of rotor ring stoichiometry from electron microscopy images of archaeal ATP synthase. Microscopy (Oxf) 2018; 67:266-273. [PMID: 30032235 DOI: 10.1093/jmicro/dfy033] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 06/20/2018] [Indexed: 12/24/2022] Open
Abstract
The 'Bayesian inference of electron microscopy' (BioEM) framework makes it possible to determine the stoichiometry of protein complexes using 3D coarse-grained models and a relatively small number of cryo-electron microscopy images as input. We applied the method to determine the most probable rotor ring stoichiometry of the archaeal Na+ ATP synthase from Pyrococcus furiosus, a multisubunit complex able to produce ATP under extreme conditions. Archaeal ATP synthases consist of a catalytic A1 part and a membrane-embedded AO portion. The AO portion is composed of a rotor ring and the a-subunit. The rotor ring of P. furiosus ATP synthase is composed of 16-kDa c-subunits, each consisting of four helices forming a bundle, with only one Na+-binding site per bundle. This ring was proposed to be decameric from LILBID-MS analysis of the entire ATP synthase. By contrast, the BioEM posterior favors a c9 ring stoichiometry. With BioEM, we ranked coarse-grained models of the whole complex with different ring geometry, using 6400 unprocessed particle images of the A1AO complex collected in vitreous ice. BioEM makes it possible to probabilistically establish the domain stoichiometry using low-resolution information and comparably few particle images.
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Affiliation(s)
- Pilar Cossio
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.,Biophysics of Tropical Diseases, Max Planck Tandem Group, University of Antioquia, Medellín, Colombia
| | - Matteo Allegretti
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Florian Mayer
- Department of Molecular Microbiology & Bioenergetics, Goethe University Frankfurt, Max-von-Laue-Strasse 9, Frankfurt am Main, Germany
| | - Volker Müller
- Department of Molecular Microbiology & Bioenergetics, Goethe University Frankfurt, Max-von-Laue-Strasse 9, Frankfurt am Main, Germany
| | - Janet Vonck
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.,Department of Physics, Goethe University Frankfurt, Max-von-Laue-Strasse 9, Frankfurt am Main, Germany
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43
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Colina-Tenorio L, Dautant A, Miranda-Astudillo H, Giraud MF, González-Halphen D. The Peripheral Stalk of Rotary ATPases. Front Physiol 2018; 9:1243. [PMID: 30233414 PMCID: PMC6131620 DOI: 10.3389/fphys.2018.01243] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/16/2018] [Indexed: 12/18/2022] Open
Abstract
Rotary ATPases are a family of enzymes that are thought of as molecular nanomotors and are classified in three types: F, A, and V-type ATPases. Two members (F and A-type) can synthesize and hydrolyze ATP, depending on the energetic needs of the cell, while the V-type enzyme exhibits only a hydrolytic activity. The overall architecture of all these enzymes is conserved and three main sectors are distinguished: a catalytic core, a rotor and a stator or peripheral stalk. The peripheral stalks of the A and V-types are highly conserved in both structure and function, however, the F-type peripheral stalks have divergent structures. Furthermore, the peripheral stalk has other roles beyond its stator function, as evidenced by several biochemical and recent structural studies. This review describes the information regarding the organization of the peripheral stalk components of F, A, and V-ATPases, highlighting the key differences between the studied enzymes, as well as the different processes in which the structure is involved.
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Affiliation(s)
- Lilia Colina-Tenorio
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Alain Dautant
- CNRS, UMR5095, IBGC, Bordeaux, France.,Energy Transducing Systems and Mitochondrial Morphology, Université de Bordeaux, Bordeaux, France
| | - Héctor Miranda-Astudillo
- Genetics and Physiology of Microalgae, InBios, PhytoSYSTEMS, University of Liège, Liège, Belgium
| | - Marie-France Giraud
- CNRS, UMR5095, IBGC, Bordeaux, France.,Energy Transducing Systems and Mitochondrial Morphology, Université de Bordeaux, Bordeaux, France
| | - Diego González-Halphen
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
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44
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Hao L, McIlroy SJ, Kirkegaard RH, Karst SM, Fernando WEY, Aslan H, Meyer RL, Albertsen M, Nielsen PH, Dueholm MS. Novel prosthecate bacteria from the candidate phylum Acetothermia. THE ISME JOURNAL 2018; 12:2225-2237. [PMID: 29884828 PMCID: PMC6092417 DOI: 10.1038/s41396-018-0187-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 02/09/2018] [Accepted: 03/20/2018] [Indexed: 02/05/2023]
Abstract
Members of the candidate phylum Acetothermia are globally distributed and detected in various habitats. However, little is known about their physiology and ecological importance. In this study, an operational taxonomic unit belonging to Acetothermia was detected at high abundance in four full-scale anaerobic digesters by 16S rRNA gene amplicon sequencing. The first closed genome from this phylum was obtained by differential coverage binning of metagenomes and scaffolding with long nanopore reads. Genome annotation and metabolic reconstruction suggested an anaerobic chemoheterotrophic lifestyle in which the bacterium obtains energy and carbon via fermentation of peptides, amino acids, and simple sugars to acetate, formate, and hydrogen. The morphology was unusual and composed of a central rod-shaped cell with bipolar prosthecae as revealed by fluorescence in situ hybridization combined with confocal laser scanning microscopy, Raman microspectroscopy, and atomic force microscopy. We hypothesize that these prosthecae allow for increased nutrient uptake by greatly expanding the cell surface area, providing a competitive advantage under nutrient-limited conditions.
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Affiliation(s)
- Liping Hao
- Department of Chemistry and Bioscience, Center for Microbial Communities, Aalborg University, Aalborg, Denmark
| | - Simon Jon McIlroy
- Department of Chemistry and Bioscience, Center for Microbial Communities, Aalborg University, Aalborg, Denmark
| | - Rasmus Hansen Kirkegaard
- Department of Chemistry and Bioscience, Center for Microbial Communities, Aalborg University, Aalborg, Denmark
| | - Søren Michael Karst
- Department of Chemistry and Bioscience, Center for Microbial Communities, Aalborg University, Aalborg, Denmark
| | | | - Hüsnü Aslan
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | - Rikke Louise Meyer
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | - Mads Albertsen
- Department of Chemistry and Bioscience, Center for Microbial Communities, Aalborg University, Aalborg, Denmark
| | - Per Halkjær Nielsen
- Department of Chemistry and Bioscience, Center for Microbial Communities, Aalborg University, Aalborg, Denmark.
| | - Morten Simonsen Dueholm
- Department of Chemistry and Bioscience, Center for Microbial Communities, Aalborg University, Aalborg, Denmark.
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45
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Yu H, Wu CH, Schut GJ, Haja DK, Zhao G, Peters JW, Adams MWW, Li H. Structure of an Ancient Respiratory System. Cell 2018; 173:1636-1649.e16. [PMID: 29754813 DOI: 10.1016/j.cell.2018.03.071] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 02/19/2018] [Accepted: 03/27/2018] [Indexed: 02/04/2023]
Abstract
Hydrogen gas-evolving membrane-bound hydrogenase (MBH) and quinone-reducing complex I are homologous respiratory complexes with a common ancestor, but a structural basis for their evolutionary relationship is lacking. Here, we report the cryo-EM structure of a 14-subunit MBH from the hyperthermophile Pyrococcus furiosus. MBH contains a membrane-anchored hydrogenase module that is highly similar structurally to the quinone-binding Q-module of complex I while its membrane-embedded ion-translocation module can be divided into a H+- and a Na+-translocating unit. The H+-translocating unit is rotated 180° in-membrane with respect to its counterpart in complex I, leading to distinctive architectures for the two respiratory systems despite their largely conserved proton-pumping mechanisms. The Na+-translocating unit, absent in complex I, resembles that found in the Mrp H+/Na+ antiporter and enables hydrogen gas evolution by MBH to establish a Na+ gradient for ATP synthesis near 100°C. MBH also provides insights into Mrp structure and evolution of MBH-based respiratory enzymes.
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Affiliation(s)
- Hongjun Yu
- Cryo-EM Structural Biology Laboratory, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Chang-Hao Wu
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Gerrit J Schut
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Dominik K Haja
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Gongpu Zhao
- David Van Andel Advanced Cryo-Electron Microsocpy Suite, Van Andel Research Institute, Grand Rapids, MI, USA
| | - John W Peters
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99163, USA
| | - Michael W W Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA.
| | - Huilin Li
- Cryo-EM Structural Biology Laboratory, Van Andel Research Institute, Grand Rapids, MI 49503, USA.
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46
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Schubert T, Adrian L, Sawers RG, Diekert G. Organohalide respiratory chains: composition, topology and key enzymes. FEMS Microbiol Ecol 2018; 94:4923014. [DOI: 10.1093/femsec/fiy035] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 02/28/2018] [Indexed: 02/07/2023] Open
Affiliation(s)
- Torsten Schubert
- Department of Applied and Ecological Microbiology, Institute of Microbiology, Friedrich Schiller University, Philosophenweg 12, D-07743 Jena, Germany
| | - Lorenz Adrian
- Department Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, D-04318 Leipzig, Germany
- Department of Geobiotechnology, Technische Universität Berlin, Ackerstraße 74, D-13355 Berlin, Germany
| | - R Gary Sawers
- Institute of Biology/Microbiology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3, D-06120 Halle (Saale), Germany
| | - Gabriele Diekert
- Department of Applied and Ecological Microbiology, Institute of Microbiology, Friedrich Schiller University, Philosophenweg 12, D-07743 Jena, Germany
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47
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Enzmann F, Mayer F, Rother M, Holtmann D. Methanogens: biochemical background and biotechnological applications. AMB Express 2018; 8:1. [PMID: 29302756 PMCID: PMC5754280 DOI: 10.1186/s13568-017-0531-x] [Citation(s) in RCA: 158] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 12/19/2017] [Indexed: 02/05/2023] Open
Abstract
Since fossil sources for fuel and platform chemicals will become limited in the near future, it is important to develop new concepts for energy supply and production of basic reagents for chemical industry. One alternative to crude oil and fossil natural gas could be the biological conversion of CO2 or small organic molecules to methane via methanogenic archaea. This process has been known from biogas plants, but recently, new insights into the methanogenic metabolism, technical optimizations and new technology combinations were gained, which would allow moving beyond the mere conversion of biomass. In biogas plants, steps have been undertaken to increase yield and purity of the biogas, such as addition of hydrogen or metal granulate. Furthermore, the integration of electrodes led to the development of microbial electrosynthesis (MES). The idea behind this technique is to use CO2 and electrical power to generate methane via the microbial metabolism. This review summarizes the biochemical and metabolic background of methanogenesis as well as the latest technical applications of methanogens. As a result, it shall give a sufficient overview over the topic to both, biologists and engineers handling biological or bioelectrochemical methanogenesis.
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Affiliation(s)
- Franziska Enzmann
- DECHEMA Research Institute, Industrial Biotechnology, Theodor-Heuss-Allee 25, 60486 Frankfurt am Main, Germany
| | - Florian Mayer
- DECHEMA Research Institute, Industrial Biotechnology, Theodor-Heuss-Allee 25, 60486 Frankfurt am Main, Germany
| | - Michael Rother
- Technische Universität Dresden, Institut für Mikrobiologie, Zellescher Weg 20b, 01217 Dresden, Germany
| | - Dirk Holtmann
- DECHEMA Research Institute, Industrial Biotechnology, Theodor-Heuss-Allee 25, 60486 Frankfurt am Main, Germany
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48
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Topçuoğlu BD, Meydan C, Orellana R, Holden JF. Formate hydrogenlyase and formate secretion ameliorate H
2
inhibition in the hyperthermophilic archaeon
Thermococcus paralvinellae. Environ Microbiol 2017; 20:949-957. [DOI: 10.1111/1462-2920.14022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 11/06/2017] [Accepted: 11/06/2017] [Indexed: 11/26/2022]
Affiliation(s)
- Begüm D. Topçuoğlu
- Department of MicrobiologyUniversity of MassachusettsAmherst MA 01003 USA
| | - Cem Meydan
- Institute for Computational Biomedicine, Weill Cornell Medical CollegeNew York NY 10021 USA
| | - Roberto Orellana
- Centro de Biotecnología, Universidad Técnica Federico Santa MaríaValparaíso Chile
| | - James F. Holden
- Department of MicrobiologyUniversity of MassachusettsAmherst MA 01003 USA
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Abstract
Some anaerobic archaea and bacteria live on substrates that do not allow the synthesis of one mol of ATP per mol of substrate via substrate level phosphorylation (SLP). Energy conservation in these cases is only possible by a chemiosmotic mechanism that involves the generation of an electrochemical ion gradient across the cytoplasmic membrane that then drives ATP synthesis via an ATP synthase. The minimal amount of energy required for ATP synthesis is thus dependent on the magnitude of the electrochemical ion gradient, the phosphorylation potential in the cell and the ion/ATP ratio of the ATP synthase. It was always thought that the minimum biological energy quantum is defined as the amount of energy required to translocate one ion across the cytoplasmic membrane. We will discuss the thermodynamics of the reactions involved in chemiosmosis and describe the limitations for ion transport and ATP synthesis that led to the proposal that at least −20 kJ/mol are required for ATP synthesis. We will challenge this hypothesis by arguing that the enzyme energizing the membrane may translocate net less than one ion: By using a primary pump connected to an antiporter module a stoichiometry below one can be obtained, implying that the minimum biological energy quantum that sustains life is even lower than assumed to date.
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Affiliation(s)
- Volker Müller
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt, Germany
| | - Verena Hess
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt, Germany
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50
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Jung HC, Lee SH, Lee SM, An YJ, Lee JH, Lee HS, Kang SG. Adaptive evolution of a hyperthermophilic archaeon pinpoints a formate transporter as a critical factor for the growth enhancement on formate. Sci Rep 2017; 7:6124. [PMID: 28733620 PMCID: PMC5522443 DOI: 10.1038/s41598-017-05424-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 05/30/2017] [Indexed: 11/26/2022] Open
Abstract
Previously, we reported that the hyperthermophilic archaeon Thermococcus onnurineus NA1 could grow on formate and produce H2. Formate conversion to hydrogen was mediated by a formate-hydrogen lyase complex and was indeed a part of chemiosmotic coupling to ATP generation. In this study, we employed an adaptation approach to enhance the cell growth on formate and investigated molecular changes. As serial transfer continued on formate-containing medium at the serum vial, cell growth, H2 production and formate consumption increased remarkably. The 156 times transferred-strain, WTF-156T, was demonstrated to enhance H2 production using formate in a bioreactor. The whole-genome sequencing of the WTF-156T strain revealed eleven mutations. While no mutation was found among the genes encoding formate hydrogen lyase, a point mutation (G154A) was identified in a formate transporter (TON_1573). The TON_1573 (A52T) mutation, when introduced into the parent strain, conferred increase in formate consumption and H2 production. Another adaptive passage, carried out by culturing repeatedly in a bioreactor, resulted in a strain, which has a mutation in TON_1573 (C155A) causing amino acid change, A52E. These results implicate that substitution of A52 residue of a formate transporter might be a critical factor to ensure the increase in formate uptake and cell growth.
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Affiliation(s)
- Hae-Chang Jung
- Korea Institute of Ocean Science and Technology, Ansan, Republic of Korea.,Department of Marine Biotechnology, Korea University of Science and Technology, Daejeon, Republic of Korea
| | - Seong Hyuk Lee
- Korea Institute of Ocean Science and Technology, Ansan, Republic of Korea
| | - Sung-Mok Lee
- Korea Institute of Ocean Science and Technology, Ansan, Republic of Korea
| | - Young Jun An
- Korea Institute of Ocean Science and Technology, Ansan, Republic of Korea
| | - Jung-Hyun Lee
- Korea Institute of Ocean Science and Technology, Ansan, Republic of Korea.,Department of Marine Biotechnology, Korea University of Science and Technology, Daejeon, Republic of Korea
| | - Hyun Sook Lee
- Korea Institute of Ocean Science and Technology, Ansan, Republic of Korea. .,Department of Marine Biotechnology, Korea University of Science and Technology, Daejeon, Republic of Korea.
| | - Sung Gyun Kang
- Korea Institute of Ocean Science and Technology, Ansan, Republic of Korea. .,Department of Marine Biotechnology, Korea University of Science and Technology, Daejeon, Republic of Korea.
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