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Systems Biology on Acetogenic Bacteria for Utilizing C1 Feedstocks. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2022; 180:57-90. [DOI: 10.1007/10_2021_199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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2
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Energy conservation under extreme energy limitation: the role of cytochromes and quinones in acetogenic bacteria. Extremophiles 2021; 25:413-424. [PMID: 34480656 PMCID: PMC8578096 DOI: 10.1007/s00792-021-01241-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 08/26/2021] [Indexed: 11/10/2022]
Abstract
Acetogenic bacteria are a polyphyletic group of organisms that fix carbon dioxide under anaerobic, non-phototrophic conditions by reduction of two mol of CO2 to acetyl-CoA via the Wood–Ljungdahl pathway. This pathway also allows for lithotrophic growth with H2 as electron donor and this pathway is considered to be one of the oldest, if not the oldest metabolic pathway on Earth for CO2 reduction, since it is coupled to the synthesis of ATP. How ATP is synthesized has been an enigma for decades, but in the last decade two ferredoxin-dependent respiratory chains were discovered. Those respiratory chains comprise of a cytochrome-free, ferredoxin-dependent respiratory enzyme complex, which is either the Rnf or Ech complex. However, it was discovered already 50 years ago that some acetogens contain cytochromes and quinones, but their role had only a shadowy existence. Here, we review the literature on the characterization of cytochromes and quinones in acetogens and present a hypothesis that they may function in electron transport chains in addition to Rnf and Ech.
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Open microbiome dominated by Clostridium and Eubacterium converts methanol into i-butyrate and n-butyrate. Appl Microbiol Biotechnol 2020; 104:5119-5131. [PMID: 32248436 DOI: 10.1007/s00253-020-10551-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 02/29/2020] [Accepted: 03/15/2020] [Indexed: 12/14/2022]
Abstract
Isobutyrate (i-butyrate) is a versatile platform chemical, whose acid form is used as a precursor of plastic and emulsifier. It can be produced microbially either using genetically engineered organisms or via microbiomes, in the latter case starting from methanol and short-chain carboxylates. This opens the opportunity to produce i-butyrate from non-sterile feedstocks. Little is known on the ecology and process conditions leading to i-butyrate production. In this study, we steered i-butyrate production in a bioreactor fed with methanol and acetate under various conditions, achieving maximum i-butyrate productivity of 5.0 mM day-1, with a concurrent production of n-butyrate of 7.9 mM day-1. The production of i-butyrate was reversibly inhibited by methanogenic inhibitor 2-bromoethanesulfonate. The microbial community data revealed the co-dominance of two major OTUs during co-production of i-butyrate and n-butyrate in two distinctive phases throughout a period of 54 days and 28 days, respectively. The cross-comparison of product profile with microbial community composition suggests that the relative abundance of Clostridium sp. over Eubacterium sp. is correlated with i-butyrate productivity over n-butyrate productivity.
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Usai G, Cirrincione S, Re A, Manfredi M, Pagnani A, Pessione E, Mazzoli R. Clostridium cellulovorans metabolism of cellulose as studied by comparative proteomic approach. J Proteomics 2020; 216:103667. [DOI: 10.1016/j.jprot.2020.103667] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/31/2019] [Accepted: 01/22/2020] [Indexed: 12/15/2022]
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Kinetic Study on Heterotrophic Growth of Acetobacterium woodii on Lignocellulosic Substrates for Acetic Acid Production. FERMENTATION-BASEL 2019. [DOI: 10.3390/fermentation5010017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Extensive research has been done on examining the autotrophic growth of Acetobacterium woodii with gaseous substrates (hydrogen and carbon dioxide) to produce acetic acid. However, only limited work has been performed on the heterotrophic growth of A. woodii using pure sugars or lignocellulosic feedstocks-derived sugars as substrates. In this study, we examine the growth kinetics and acetic acid production of A. woodii on glucose and xylose. While good growth was observed with glucose as substrate, no significant growth was obtained on xylose. Kinetic studies were performed in batch culture using different concentrations of glucose, ranging from 5 g/L to 40 g/L. The highest acetate production of 6.919 g/L with a product yield of 0.76 g acetic acid/g glucose was observed with 10 g/L glucose as initial substrate concentration. When testing A. woodii on corn stover hydrolysate (CSH) and wheat straw hydrolysate (WSH) formed after pretreatment and enzymatic hydrolysis, we found that A. woodii showed acetic acid production of 7.64 g/L and a product yield of 0.70 g acetic acid/g of glucose on WSH, while the acetic acid production was 7.83 g/L with a product yield of 0.65 g acetic acid/g of glucose on CSH. These results clearly demonstrate that A. woodii performed similarly on pure substrates and hydrolysates, and that the processes were not inhibited by the heterogenous components present in the lignocellulosic feedstock hydrolysates.
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Müller V, Chowdhury NP, Basen M. Electron Bifurcation: A Long-Hidden Energy-Coupling Mechanism. Annu Rev Microbiol 2018; 72:331-353. [PMID: 29924687 DOI: 10.1146/annurev-micro-090816-093440] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A decade ago, a novel mechanism to drive thermodynamically unfavorable redox reactions was discovered that is used in prokaryotes to drive endergonic electron transfer reactions by a direct coupling to an exergonic redox reaction in one soluble enzyme complex. This process is referred to as flavin-based electron bifurcation, or FBEB. An important function of FBEB is that it allows the generation of reduced low-potential ferredoxin (Fdred) from comparably high-potential electron donors such as NADH or molecular hydrogen (H2). Fdred is then the electron donor for anaerobic respiratory chains leading to the synthesis of ATP. In many metabolic scenarios, Fd is reduced by metabolic oxidoreductases and Fdred then drives endergonic metabolic reactions such as H2 production by the reverse, electron confurcation. FBEB is energetically more economical than ATP hydrolysis or reverse electron transport as a driving force for endergonic redox reactions; thus, it does "save" cellular ATP. It is essential for autotrophic growth at the origin of life and also allows for heterotrophic growth on certain low-energy substrates.
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Affiliation(s)
- Volker Müller
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, 60438 Frankfurt, Germany;
| | - Nilanjan Pal Chowdhury
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, 60438 Frankfurt, Germany;
| | - Mirko Basen
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, 60438 Frankfurt, Germany;
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Momper L, Kiel Reese B, Zinke L, Wanger G, Osburn MR, Moser D, Amend JP. Major phylum-level differences between porefluid and host rock bacterial communities in the terrestrial deep subsurface. ENVIRONMENTAL MICROBIOLOGY REPORTS 2017; 9:501-511. [PMID: 28677247 DOI: 10.1111/1758-2229.12563] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 01/06/2017] [Accepted: 06/19/2017] [Indexed: 06/07/2023]
Abstract
Earth's deep subsurface biosphere (DSB) is home to a vast number and wide variety of microorganisms. Although difficult to access and sample, deep subsurface environments have been probed through drilling programs, exploration of mines and sampling of deeply sourced vents and springs. In an effort to understand the ecology of deep terrestrial habitats, we examined bacterial diversity in the Sanford Underground Research Facility (SURF), the former Homestake gold mine, in South Dakota, USA. Whole genomic DNA was extracted from deeply circulating groundwater and corresponding host rock (at a depth of 1.45 km below ground surface). Pyrotag DNA sequencing of the 16S rRNA gene revealed diverse communities of putative chemolithoautotrophs, aerobic and anaerobic heterotrophs, numerous candidate phyla and unique rock-associated microbial assemblage. There was a clear and near-total separation of communities between SURF deeply circulating fracture fluids and SURF host-rocks. Sequencing data from SURF compared against five similarly sequenced terrestrial subsurface sites in Europe and North America revealed classes Clostridia and Betaproteobacteria were dominant in terrestrial fluids. This study presents a unique analysis showing differences in terrestrial subsurface microbial communities between fracture fluids and host rock through which those fluids permeate.
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Affiliation(s)
- Lily Momper
- Department of Biological Sciences, Marine Environmental Biology Section, University of Southern California, Los Angeles, CA, USA
| | - Brandi Kiel Reese
- Department of Life Sciences, Texas A&M University, Corpus Christi, TX, USA
| | - Laura Zinke
- Department of Biological Sciences, Marine Environmental Biology Section, University of Southern California, Los Angeles, CA, USA
| | - Greg Wanger
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA
| | - Magdalena R Osburn
- Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL, USA
| | - Duane Moser
- Division of Earth and Ecosystem Sciences, Desert Research Institute, Las Vegas, NV, USA
| | - Jan P Amend
- Department of Biological Sciences, Marine Environmental Biology Section, University of Southern California, Los Angeles, CA, USA
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA
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Amin A, Ahmed I, Salam N, Kim BY, Singh D, Zhi XY, Xiao M, Li WJ. Diversity and Distribution of Thermophilic Bacteria in Hot Springs of Pakistan. MICROBIAL ECOLOGY 2017; 74:116-127. [PMID: 28105510 DOI: 10.1007/s00248-017-0930-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 01/02/2017] [Indexed: 06/06/2023]
Abstract
Chilas and Hunza areas, located in the Main Mantle Thrust and Main Karakoram Thrust of the Himalayas, host a range of geochemically diverse hot springs. This Himalayan geothermal region encompassed hot springs ranging in temperature from 60 to 95 °C, in pH from 6.2 to 9.4, and in mineralogy from bicarbonates (Tato Field), sulfates (Tatta Pani) to mixed type (Murtazaabad). Microbial community structures in these geothermal springs remained largely unexplored to date. In this study, we report a comprehensive, culture-independent survey of microbial communities in nine samples from these geothermal fields by employing a bar-coded pyrosequencing technique. The bacterial phyla Proteobacteria and Chloroflexi were dominant in all samples from Tato Field, Tatta Pani, and Murtazaabad. The community structures however depended on temperature, pH, and physicochemical parameters of the geothermal sites. The Murtazaabad hot springs with relatively higher temperature (90-95 °C) favored the growth of phylum Thermotogae, whereas the Tatta Pani thermal spring site TP-H3-b (60 °C) favored the phylum Proteobacteria. At sites with low silica and high temperature, OTUs belonging to phylum Chloroflexi were dominant. Deep water areas of the Murtazaabad hot springs favored the sulfur-reducing bacteria. About 40% of the total OTUs obtained from these samples were unclassified or uncharacterized, suggesting the presence of many undiscovered and unexplored microbiota. This study has provided novel insights into the nature of ecological interactions among important taxa in these communities, which in turn will help in determining future study courses in these sites.
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Affiliation(s)
- Arshia Amin
- Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, People's Republic of China
- Institute of Microbial Culture Collection of Pakistan (IMCCP), National Agricultural Research Centre (NARC), Islamabad, 45500, Pakistan
- Department of Microbiology, Quaid-e-Azam University, Islamabad, 45320, Pakistan
| | - Iftikhar Ahmed
- Institute of Microbial Culture Collection of Pakistan (IMCCP), National Agricultural Research Centre (NARC), Islamabad, 45500, Pakistan.
| | - Nimaichand Salam
- State Key Laboratory of Biocontrol and Guandong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Byung-Yong Kim
- Chun Lab Inc., Seoul National University, Seoul, 151-742, Republic of South Korea
| | - Dharmesh Singh
- Environmental Genomics Division, National Environmental Engineering Research Institute (CSIR-NEERI), Nagpur, 440024, India
| | - Xiao-Yang Zhi
- Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, People's Republic of China
| | - Min Xiao
- State Key Laboratory of Biocontrol and Guandong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Wen-Jun Li
- Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, People's Republic of China.
- State Key Laboratory of Biocontrol and Guandong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China.
- Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi, 830011, People's Republic of China.
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Nonacetogenic growth of the acetogen Acetobacterium woodii on 1,2-propanediol. J Bacteriol 2014; 197:382-91. [PMID: 25384483 DOI: 10.1128/jb.02383-14] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acetogenic bacteria can grow by the oxidation of various substrates coupled to the reduction of CO2 in the Wood-Ljungdahl pathway. Here, we show that growth of the acetogen Acetobacterium woodii on 1,2-propanediol (1,2-PD) as the sole carbon and energy source is independent of acetogenesis. Enzymatic measurements and metabolite analysis revealed that 1,2-PD is dehydrated to propionaldehyde, which is further oxidized to propionyl coenzyme A (propionyl-CoA) with concomitant reduction of NAD. NADH is reoxidized by reducing propionaldehyde to propanol. The potential gene cluster coding for the responsible enzymes includes genes coding for shell proteins of bacterial microcompartments. Electron microscopy revealed the presence of microcompartments as well as storage granules in cells grown on 1,2-PD. Gene clusters coding for the 1,2-PD pathway can be found in other acetogens as well, but the distribution shows no relation to the phylogeny of the organisms.
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10
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Autotrophy at the thermodynamic limit of life: a model for energy conservation in acetogenic bacteria. Nat Rev Microbiol 2014; 12:809-21. [DOI: 10.1038/nrmicro3365] [Citation(s) in RCA: 505] [Impact Index Per Article: 50.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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11
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Evidence for a hexaheteromeric methylenetetrahydrofolate reductase in Moorella thermoacetica. J Bacteriol 2014; 196:3303-14. [PMID: 25002540 DOI: 10.1128/jb.01839-14] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Moorella thermoacetica can grow with H₂ and CO₂, forming acetic acid from 2 CO₂ via the Wood-Ljungdahl pathway. All enzymes involved in this pathway have been characterized to date, except for methylenetetrahydrofolate reductase (MetF). We report here that the M. thermoacetica gene that putatively encodes this enzyme, metF, is part of a transcription unit also containing the genes hdrCBA, mvhD, and metV. MetF copurified with the other five proteins encoded in the unit in a hexaheteromeric complex with an apparent molecular mass in the 320-kDa range. The 40-fold-enriched preparation contained per mg protein 3.1 nmol flavin adenine dinucleotide (FAD), 3.4 nmol flavin mononucleotide (FMN), and 110 nmol iron, almost as predicted from the primary structure of the six subunits. It catalyzed the reduction of methylenetetrahydrofolate with reduced benzyl viologen but not with NAD(P)H in either the absence or presence of oxidized ferredoxin. It also catalyzed the reversible reduction of benzyl viologen with NADH (diaphorase activity). Heterologous expression of the metF gene in Escherichia coli revealed that the subunit MetF contains one FMN rather than FAD. MetF exhibited 70-fold-higher methylenetetrahydrofolate reductase activity with benzyl viologen when produced together with MetV, which in part shows sequence similarity to MetF. Heterologously produced HdrA contained 2 FADs and had NAD-specific diaphorase activity. Our results suggested that the physiological electron donor for methylenetetrahydrofolate reduction in M. thermoacetica is NADH and that the exergonic reduction of methylenetetrahydrofolate with NADH is coupled via flavin-based electron bifurcation with the endergonic reduction of an electron acceptor, whose identity remains unknown.
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12
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Farhana A, Saini V, Kumar A, Lancaster JR, Steyn AJ. Environmental heme-based sensor proteins: implications for understanding bacterial pathogenesis. Antioxid Redox Signal 2012; 17:1232-45. [PMID: 22494151 PMCID: PMC3430476 DOI: 10.1089/ars.2012.4613] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 04/11/2012] [Indexed: 11/13/2022]
Abstract
SIGNIFICANCE Heme is an important prosthetic group required in a wide array of functions, including respiration, photosynthesis, metabolism, O(2) transport, xenobiotic detoxification, and peroxide production and destruction, and is an essential cofactor in proteins such as catalases, peroxidases, and members of the cytochrome P450 superfamily. Importantly, bacterial heme-based sensor proteins exploit the redox chemistry of heme to sense environmental gases and the intracellular redox state of the cell. RECENT ADVANCES The bacterial proteins FixL (Rhizobium ssp.), CooA (Rhodospirillum rubrum), EcDos (Escherichia. coli), RcoM (Burkholderia xenovorans), and particularly Mycobacterium tuberculosis (Mtb) DosS and DosT have emerged as model paradigms of environmental heme-based sensors capable of detecting multiple gases including NO, CO, and O(2). CRITICAL ISSUES How the diatomic gases NO, CO, or O(2) bind to heme iron to generate Fe-NO, Fe-CO, and Fe-O(2) bonds, respectively, and how the oxidation of heme iron by O(2) serves as a sensing mechanism that controls the activity of key proteins is complex and largely unclear. This is particularly important as many bacterial pathogens, including Mtb, encounters three overlapping host gases (NO, CO, and O(2)) during human infection. FUTURE DIRECTIONS Heme is an important prosthetic group that monitors the microbe's internal and external surroundings to alter signal transduction or enzymatic activation. Modern expression, metabolomic and biochemical technologies combined with in vivo pathogenesis studies should provide fresh insights into the mechanism of action of heme-based redox sensors.
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Affiliation(s)
- Aisha Farhana
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Vikram Saini
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Ashwani Kumar
- Institute of Microbial Technology, Chandigarh, India
| | - Jack R. Lancaster
- Department of Anesthesiology, Physiology and Biophysics, and Environmental Sciences, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Free Radical Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Adrie J.C. Steyn
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Free Radical Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Centers for AIDS Research, University of Alabama at Birmingham, Birmingham, Alabama
- KwaZulu-Natal Research Institute for Tuberculosis and HIV, Durban, South Africa
- Department of Pathology, Nelson Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
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Poehlein A, Schmidt S, Kaster AK, Goenrich M, Vollmers J, Thürmer A, Bertsch J, Schuchmann K, Voigt B, Hecker M, Daniel R, Thauer RK, Gottschalk G, Müller V. An ancient pathway combining carbon dioxide fixation with the generation and utilization of a sodium ion gradient for ATP synthesis. PLoS One 2012; 7:e33439. [PMID: 22479398 PMCID: PMC3315566 DOI: 10.1371/journal.pone.0033439] [Citation(s) in RCA: 190] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 02/09/2012] [Indexed: 11/18/2022] Open
Abstract
Synthesis of acetate from carbon dioxide and molecular hydrogen is considered to be the first carbon assimilation pathway on earth. It combines carbon dioxide fixation into acetyl-CoA with the production of ATP via an energized cell membrane. How the pathway is coupled with the net synthesis of ATP has been an enigma. The anaerobic, acetogenic bacterium Acetobacterium woodii uses an ancient version of this pathway without cytochromes and quinones. It generates a sodium ion potential across the cell membrane by the sodium-motive ferredoxin:NAD oxidoreductase (Rnf). The genome sequence of A. woodii solves the enigma: it uncovers Rnf as the only ion-motive enzyme coupled to the pathway and unravels a metabolism designed to produce reduced ferredoxin and overcome energetic barriers by virtue of electron-bifurcating, soluble enzymes.
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Affiliation(s)
- Anja Poehlein
- Göttingen Genomics Laboratory, Institute for Microbiology and Genetics, Georg August University, Göttingen, Germany
| | - Silke Schmidt
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt, Germany
| | | | - Meike Goenrich
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - John Vollmers
- Göttingen Genomics Laboratory, Institute for Microbiology and Genetics, Georg August University, Göttingen, Germany
| | - Andrea Thürmer
- Göttingen Genomics Laboratory, Institute for Microbiology and Genetics, Georg August University, Göttingen, Germany
| | - Johannes Bertsch
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt, Germany
| | - Kai Schuchmann
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt, Germany
| | - Birgit Voigt
- Institute for Microbiology, Ernst Moritz Arndt University Greifswald, Greifswald, Germany
| | - Michael Hecker
- Institute for Microbiology, Ernst Moritz Arndt University Greifswald, Greifswald, Germany
| | - Rolf Daniel
- Göttingen Genomics Laboratory, Institute for Microbiology and Genetics, Georg August University, Göttingen, Germany
| | - Rudolf K. Thauer
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Gerhard Gottschalk
- Göttingen Genomics Laboratory, Institute for Microbiology and Genetics, Georg August University, Göttingen, Germany
| | - Volker Müller
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt, Germany
- * E-mail:
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Abstract
Frankly, I was surprised to receive an invitation to write a prefatory chapter for the Annual Review of Microbiology. I have read several such chapters written by outstanding researchers, many of whom I know and admire. I did not think I belonged to such a preeminent group. In my view, my contributions to the physiology and biochemistry of anaerobic thermophilic bacteria and, more lately, to anaerobic fungi are modest compared to the contribution made by other authors of prefatory chapters. I am honored to write about my life and my work, and I hope that those who read this chapter will sense how exciting and rewarding they have been.
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Affiliation(s)
- Lars G Ljungdahl
- Department of Biochemistry and Molecular Biology, The University of Georgia, Athens, Georgia 30602, USA.
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15
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Abstract
Acetogens utilize the acetyl-CoA Wood-Ljungdahl pathway as a terminal electron-accepting, energy-conserving, CO(2)-fixing process. The decades of research to resolve the enzymology of this pathway (1) preceded studies demonstrating that acetogens not only harbor a novel CO(2)-fixing pathway, but are also ecologically important, and (2) overshadowed the novel microbiological discoveries of acetogens and acetogenesis. The first acetogen to be isolated, Clostridium aceticum, was reported by Klaas Tammo Wieringa in 1936, but was subsequently lost. The second acetogen to be isolated, Clostridium thermoaceticum, was isolated by Francis Ephraim Fontaine and co-workers in 1942. C. thermoaceticum became the most extensively studied acetogen and was used to resolve the enzymology of the acetyl-CoA pathway in the laboratories of Harland Goff Wood and Lars Gerhard Ljungdahl. Although acetogenesis initially intrigued few scientists, this novel process fostered several scientific milestones, including the first (14)C-tracer studies in biology and the discovery that tungsten is a biologically active metal. The acetyl-CoA pathway is now recognized as a fundamental component of the global carbon cycle and essential to the metabolic potentials of many different prokaryotes. The acetyl-CoA pathway and variants thereof appear to be important to primary production in certain habitats and may have been the first autotrophic process on earth and important to the evolution of life. The purpose of this article is to (1) pay tribute to those who discovered acetogens and acetogenesis, and to those who resolved the acetyl-CoA pathway, and (2) highlight the ecology and physiology of acetogens within the framework of their scientific roots.
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Affiliation(s)
- Harold L Drake
- Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany.
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Dilling S, Imkamp F, Schmidt S, Müller V. Regulation of caffeate respiration in the acetogenic bacterium Acetobacterium woodii. Appl Environ Microbiol 2007; 73:3630-6. [PMID: 17416687 PMCID: PMC1932707 DOI: 10.1128/aem.02060-06] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The anaerobic acetogenic bacterium Acetobacterium woodii can conserve energy by oxidation of various substrates coupled to either carbonate or caffeate respiration. We used a cell suspension system to study the regulation and kinetics of induction of caffeate respiration. After addition of caffeate to suspensions of fructose-grown cells, there was a lag phase of about 90 min before caffeate reduction commenced. However, in the presence of tetracycline caffeate was not reduced, indicating that de novo protein synthesis is required for the ability to respire caffeate. Induction also took place in the presence of CO(2), and once a culture was induced, caffeate and CO(2) were used simultaneously as electron acceptors. Induction of caffeate reduction was also observed with H(2) plus CO(2) as the substrate, but the lag phase was much longer. Again, caffeate and CO(2) were used simultaneously as electron acceptors. In contrast, during oxidation of methyl groups derived from methanol or betaine, acetogenesis was the preferred energy-conserving pathway, and caffeate reduction started only after acetogenesis was completed. The differential flow of reductants was also observed with suspensions of resting cells in which caffeate reduction was induced prior to harvest of the cells. These cell suspensions utilized caffeate and CO(2) simultaneously with fructose or hydrogen as electron donors, but CO(2) was preferred over caffeate during methyl group oxidation. Caffeate-induced resting cells could reduce caffeate and also p-coumarate or ferulate with hydrogen as the electron donor. p-Coumarate or ferulate also served as an inducer for caffeate reduction. Interestingly, caffeate-induced cells reduced ferulate in the absence of an external reductant, indicating that caffeate also induces the enzymes required for oxidation of the methyl group of ferulate.
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Affiliation(s)
- Sabrina Dilling
- Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
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Sipma J, Henstra AM, Parshina SM, Lens PN, Lettinga G, Stams AJM. Microbial CO conversions with applications in synthesis gas purification and bio-desulfurization. Crit Rev Biotechnol 2006; 26:41-65. [PMID: 16594524 DOI: 10.1080/07388550500513974] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Recent advances in the field of microbial physiology demonstrate that carbon monoxide is a readily used substrate by a wide variety of anaerobic micro-organisms, and may be employed in novel biotechnological processes for production of bulk and fine chemicals or in biological treatment of waste streams. Synthesis gas produced from fossil fuels or biomass is rich in hydrogen and carbon monoxide. Conversion of carbon monoxide to hydrogen allows use of synthesis gas in existing hydrogen utilizing processes and is interesting in view of a transition from hydrogen production from fossil fuels to sustainable (CO2-neutral) biomass. The conversion of CO with H2O to CO2 and H2 is catalyzed by a rapidly increasing group of micro-organisms. Hydrogen is a preferred electron donor in biotechnological desulfurization ofwastewaters and flue gases. Additionally, CO is a good alternative electron donor considering the recent isolation of a CO oxidizing, sulfate reducing bacterium. Here we review CO utilization by various anaerobic micro-organisms and their possible role in biotechnological processes, with a focus on hydrogen production and bio-desulfurization.
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Affiliation(s)
- Jan Sipma
- Sub-department of Environmental Technology, Wageningen University, Wageningen, The Netherlands
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18
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Wahyudi AT, Takeyama H, Okamura Y, Fukuda Y, Matsunaga T. Characterization of aldehyde ferredoxin oxidoreductase gene defective mutant in Magnetospirillum magneticum AMB-1. Biochem Biophys Res Commun 2003; 303:223-9. [PMID: 12646191 DOI: 10.1016/s0006-291x(03)00303-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A non-magnetic mutant of Magnetospirillum magneticum AMB-1, designated as NMA21, was generated by mini-Tn5 transposon mutagenesis to identify genes involved in bacterial magnetic particle (BMP) synthesis. Alignment of the DNA sequences flanking the transposon allowed the isolation of an open reading frame (ORF2) within an operon consisting of five genes. The amino acid sequence of ORF2 showed homology with tungsten-containing aldehyde ferredoxin oxidoreductase (AOR) from Pyrococcus furiosus (48% identity and 64% similarity), which functions for aldehyde oxidation. AOR was found to be expressed under microaerobic conditions and localized in the cytoplasm of AMB-1. Iron uptake and growth of NMA21 were lower than wild type. Transmission electron microscopy (TEM) of NMA21 revealed that no BMPs were completely synthesized, but polyhydroxybutyrate (PHB)-like granules were persistently produced. These results indicate that AOR may contribute to ferric iron reduction during BMP synthesis in M. magneticum AMB-1 under microaerobic respiration.
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Affiliation(s)
- Aris Tri Wahyudi
- Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16 Naka-Cho, Koganei, Tokyo 184-8588, Japan
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19
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Affiliation(s)
- F E Jenney
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
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20
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Ozawa K, Meikari T, Motohashi K, Yoshida M, Akutsu H. Evidence for the presence of an F-type ATP synthase involved in sulfate respiration in Desulfovibrio vulgaris. J Bacteriol 2000; 182:2200-6. [PMID: 10735863 PMCID: PMC111269 DOI: 10.1128/jb.182.8.2200-2206.2000] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Using a library of genomic DNA from Desulfovibrio vulgaris Miyazaki F, a strict anaerobe, and two synthetic deoxyoligonucleotide probes designed for F-type ATPases, the genes for open reading frames (ORFs) 1 to 5 were cloned and sequenced. The predicted protein sequences of the gene products indicate that they are composed of 172, 488, 294, 471, and 134 amino acids, respectively, and that they share considerable identity at the amino acid level with delta, alpha, gamma, beta, and epsilon subunits found in other F-type ATPases, respectively. Furthermore, a component carrying ATPase activity was partially purified from the cytoplasmic membrane fraction of the D. vulgaris Miyazaki F cells. The N-terminal amino acid sequences of three major polypeptides separated by sodium dodecyl sulfate-12% polyacrylamide gel electrophoresis were identical to those of the products predicted by the sequences of ORF-2, ORF-3, and ORF-4, suggesting that an F-type ATPase is functioning in the D. vulgaris Miyazaki F cytoplasmic membrane. The amount of the F-type ATPase produced in the D. vulgaris Miyazaki F cells is similar to that in the Escherichia coli cells cultured aerobically. It indicates that the enzyme works as an ATP synthase in the D. vulgaris Miyazaki F cells in connection with sulfate respiration.
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Affiliation(s)
- K Ozawa
- Department of Chemistry and Biotechnology, Faculty of Engineering, Yokohama National University, Hodogaya-ku, Yokohama 240-8501, Japan
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21
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Ratajczak A, Geissdörfer W, Hillen W. Expression of alkane hydroxylase from Acinetobacter sp. Strain ADP1 is induced by a broad range of n-alkanes and requires the transcriptional activator AlkR. J Bacteriol 1998; 180:5822-7. [PMID: 9811637 PMCID: PMC107653 DOI: 10.1128/jb.180.22.5822-5827.1998] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Acinetobacter sp. strain ADP1, alkane degradation depends on at least five essential genes. rubAB and xcpR are constitutively transcribed. Here we describe inducible transcription of alkM, which strictly depends on the presence of the transcriptional activator AlkR. alkR itself is expressed at a low level, while a chromosomally located alkM::lacZ fusion is inducible by middle-chain-length alkanes from heptane to undecane, which do not support growth of ADP1, and by long-chain-length alkanes from dodecane to octadecane, which are used as sources of carbon and energy. The putative AlkM substrate 1-dodecene is also an effective inducer. Products of alkane hydroxylase activity like 1-dodecanol prevent induction of alkM expression. alkM is expressed only in stationary phase, suggesting its dependence on at least one other regulatory mechanism.
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Affiliation(s)
- A Ratajczak
- Lehrstuhl für Mikrobiologie, Institut für Mikrobiologie, Biochemie und Genetik der Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Federal Republic of Germany
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22
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Mägli A, Messmer M, Leisinger T. Metabolism of Dichloromethane by the Strict Anaerobe Dehalobacterium formicoaceticum. Appl Environ Microbiol 1998; 64:646-50. [PMID: 16349505 PMCID: PMC106096 DOI: 10.1128/aem.64.2.646-650.1998] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/1997] [Accepted: 11/07/1997] [Indexed: 11/20/2022] Open
Abstract
The metabolism of dichloromethane by Dehalobacterium formicoaceticum in cell suspensions and crude cell extracts was investigated. The organism is a strictly anaerobic gram-positive bacterium that utilizes exclusively dichloromethane as a growth substrate and ferments this compound to formate and acetate in a molar ratio of 2:1. When [C]dichloromethane was degraded by cell suspensions, formate, the methyl group of acetate, and minor amounts of methanol were labeled, but there was no nuclear magnetic resonance signal corresponding to the carboxyl group of acetate. This finding and previously established carbon and electron balances suggested that dichloromethane was converted to methylene tetrahydrofolate, of which two-thirds was oxidized to formate while one-third gave rise to acetate by incorporation of CO(2) from the medium in the acetyl coenzyme A synthase reaction. When crude desalted extracts were incubated in the presence of dichloromethane, tetrahydrofolate, ATP, methyl viologen, and molecular hydrogen, dichloromethane and tetrahydrofolate were consumed, with the concomitant formation of stoichiometric amounts of methylene tetrahydrofolate. The in vitro transfer of the methylene group of dichloromethane onto tetrahydrofolate required substoichiometric amounts of ATP. The reaction was inhibited in a light-reversible fashion by 20 muM propyl iodide, thus suggesting involvement of a Co(I) corrinoid in the anoxic dehalogenation of dichloromethane. D. formicoaceticum exhibited normal growth with 0.8 mM sodium in the medium, and crude extracts contained ATPase activity that was partially inhibited by N,N'-dicyclohexylcarbodiimide and azide. During growth with dichloromethane, the organism thus may conserve energy not only by substrate-level phosphorylation but also by a chemiosmotic mechanism involving a sodium-independent F(0)F(1)-type ATP synthase.
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Affiliation(s)
- A Mägli
- Mikrobiologisches Institut, ETH Zürich, CH-8092 Zürich, Switzerland
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23
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Swartz PD, Ichiye T. Protein contributions to redox potentials of homologous rubredoxins: an energy minimization study. Biophys J 1997; 73:2733-41. [PMID: 9370467 PMCID: PMC1181175 DOI: 10.1016/s0006-3495(97)78302-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The energetic contributions of the protein to the redox potential in an iron-sulfur protein are studied via energy minimization, comparing homologous rubredoxins from Clostridium pasteurianum, Desulfovibrio gigas, Desulfovibrio vulgaris, and Pyrococcus furiosus. The reduction reaction was divided into 1) the change in the redox site charge without allowing the protein to respond and 2) the relaxation of the protein in response to the new charge state, focusing on the latter. The energy minimizations predict structural relaxation near the redox site that agrees well with that in crystal structures of oxidized and reduced P. furiosus rubredoxin, but underpredicts it far from the redox site. However, the relaxation energies from the energy-minimized structures agree well with those from the crystal structures, because the polar groups near the redox site are the main determinants and the charged groups are all located at the surface and thus are screened dielectrically. Relaxation energies are necessary for good agreement with experimentally observed differences in reduction energies between C. pasteurianum and the other three rubredoxins. Overall, the relaxation energy is large (over 500 mV) from both the energy-minimized and the crystal structures. In addition, the range in the relaxation energy for the different rubredoxins is large (300 mV), because even though the structural perturbations of the polar groups are small, they are very near the redox site. Thus the relaxation energy is an important factor to consider in reduction energetics.
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Affiliation(s)
- P D Swartz
- Department of Biochemistry and Biophysics, Washington State University, Pullman 99164-4660, USA
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24
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Das A, Ljungdahl LG. Composition and primary structure of the F1F0 ATP synthase from the obligately anaerobic bacterium Clostridium thermoaceticum. J Bacteriol 1997; 179:3746-55. [PMID: 9171425 PMCID: PMC179173 DOI: 10.1128/jb.179.11.3746-3755.1997] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The subunit composition and primary structure of the proton-translocating F1F0 ATP synthase have been determined in Clostridium thermoaceticum. The isolated enzyme has a subunit composition identical to that of the F1F0 ATP synthase purified from Clostridium thermoautotrophicum (A. Das, D. M. Ivey, and L. G. Ljungdahl, J. Bacteriol. 179:1714-1720, 1997), both having six different polypeptides. The molecular masses of the six subunits were 60, 50, 32, 17, 19, and 8 kDa, and they were identified as alpha, beta, gamma, delta, epsilon, and c, respectively, based on their reactivity with antibodies against the F1 ATPase purified from C. thermoautotrophicum and by comparing their N-terminal amino acid sequences with that deduced from the cloned genes of the C. thermoaceticum atp operon. The subunits a and b found in many bacterial ATP synthases could not be detected either in the purified ATP synthase or crude membranes of C. thermoaceticum. The C. thermoaceticum atp operon contained nine genes arranged in the order atpI (i), atpB (a), atpE (c), atpF (b), atpH (delta), atpA (alpha), atpG (gamma), atpD (beta), and atpC (epsilon). The deduced protein sequences of the C. thermoaceticum ATP synthase subunits were comparable with those of the corresponding subunits from Escherichia coli, thermophilic Bacillus strain PS3, Rhodospirillum rubrum, spinach chloroplasts, and the cyanobacterium Synechococcus strain PCC 6716. The analysis of total RNA by Northern hybridization experiments reveals the presence of transcripts (mRNA) of the genes i, a, and b subunits not found in the isolated enzyme. Analysis of the nucleotide sequence of the atp genes reveals overlap of the structural genes for the i and a subunits and the presence of secondary structures (in the b gene) which could influence the posttranscriptional regulation of the corresponding genes.
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Affiliation(s)
- A Das
- Center for Biological Resource Recovery and Department of Biochemistry and Molecular Biology, University of Georgia, Athens 30602, USA
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25
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Das A, Ivey DM, Ljungdahl LG. Purification and reconstitution into proteoliposomes of the F1F0 ATP synthase from the obligately anaerobic gram-positive bacterium Clostridium thermoautotrophicum. J Bacteriol 1997; 179:1714-20. [PMID: 9045833 PMCID: PMC178886 DOI: 10.1128/jb.179.5.1714-1720.1997] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The proton-translocating F1F0 ATP synthase from Clostridium thermoautotrophicum was solubilized from cholate-washed membranes with Zwittergent 3-14 at 58 degrees C and purified in the presence of octylglucoside by sucrose gradient centrifugation and ion-exchange chromatography on a DEAE-5PW column. The purified enzyme hydrolyzed ATP at a rate of 12.6 micromol min(-1) mg(-1) at 58 degrees C and pH 8.5. It was composed of six different polypeptides with molecular masses of 60, 50, 32, 19, 17, and 8 kDa. These were identified as alpha, beta, gamma, delta, epsilon, and c subunits, respectively, as their N-terminal amino acid sequences matched the deduced N-terminal amino acid sequences of the corresponding genes of the atp operon sequenced from Clostridium thermoaceticum (GenBank accession no. U64318), demonstrating the close similarity of the F1F0 complexes from C. thermoaceticum and C. thermoautotrophicum. Four of these subunits, alpha, beta, gamma, and epsilon, constituted the F1-ATPase purified from the latter bacterium. The delta subunit could not be found in the purified F1 although it was present in the F1F0 complex, indicating that the F0 moiety consisted of the delta and the c subunits and lacked the a and b subunits found in many aerobic bacteria. The c subunit was characterized as N,N'-dicyclohexylcarbodiimide reactive. The F1F0 complex of C. thermoautotrophicum consisting of subunits alpha, beta, gamma, delta, epsilon, and c was reconstituted with phospholipids into proteoliposomes which had ATP-Pi exchange, carbonylcyanide p-trifluoromethoxy-phenylhydrazone-stimulated ATPase, and ATP-dependent proton-pumping activities. Immunoblot analyses of the subunits of ATP synthases from C. thermoautotrophicum, C. thermoaceticum, and Escherichia coli revealed antigenic similarities among the F1 subunits from both clostridia and the beta subunit of F1 from E. coli.
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Affiliation(s)
- A Das
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens 30602, USA
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26
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Lebloas P, Lindley ND, Loubiere P. Regulation of carbon and energy metabolism during the linear growth phase in batch fermentations of the acetogenic methylotroph Eubacterium limosum on methanol/CO2. Enzyme Microb Technol 1996. [DOI: 10.1016/0141-0229(95)00230-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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27
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Differential effects of sodium ions on motility in the homoacetogenic bacteriaAcetobacterium woodii andSporomusa sphaeroides. Arch Microbiol 1995. [DOI: 10.1007/bf02529984] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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28
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Abstract
Homoacetogenic bacteria are strictly anaerobic microorganisms that catalyze the formation of acetate from C1 units in their energy metabolism. Most of these organisms are able to grow at the expense of hydrogen plus CO2 as the sole energy source. Hydrogen then serves as the electron donor for CO2 reduction to acetate. The methyl group of acetate is formed from CO2 via formate and reduced C1 intermediates bound to tetrahydrofolate. The carboxyl group is derived from carbon monoxide, which is synthesized from CO2 by carbon monoxide dehydrogenase. The latter enzyme also catalyzes the formation of acetyl-CoA from the methyl group plus CO. Acetyl-CoA is then converted either to acetate in the catabolism or to cell carbon in the anabolism of the bacteria. The homoacetogens are very versatile anaerobes, which convert a variety of different substrates to acetate as the major end product.
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Affiliation(s)
- G Diekert
- Institut für Mikrobiologie, Universität Stuttgart, Germany
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29
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Daniel SL, Drake HL. Oxalate- and Glyoxylate-Dependent Growth and Acetogenesis by
Clostridium thermoaceticum. Appl Environ Microbiol 1993; 59:3062-9. [PMID: 16349048 PMCID: PMC182407 DOI: 10.1128/aem.59.9.3062-3069.1993] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The acetogenic bacterium
Clostridium thermoaceticum
ATCC 39073 grew at the expense of the two-carbon substrates oxalate and glyoxylate. Other two-carbon substrates (acetaldehyde, acetate, ethanol, ethylene glycol, glycolaldehyde, glycolate, and glyoxal) were not growth supportive. Growth increased linearly with increasing substrate concentrations up to 45 mM oxalate and glyoxylate, and supplemental CO
2
was not required for growth. Oxalate and glyoxylate yielded 4.9 and 9.4 g, respectively, of cell biomass (dry weight) per mol of substrate utilized. Acetate was the major reduced end product recovered from oxalate and glyoxylate cultures.
14
C labeling studies showed that oxalate was subject to decarboxylation, and product analysis indicated that oxalate was utilized by the following reaction: 4
-
OOC-COO
-
+ 5H
2
O → CH
3
COO
-
+ 6HCO
3
-
+ OH
-
. Oxalate- and glyoxylate-dependent growth produced lower acetate concentrations per unit of cell biomass synthesized than did H
2
-, CO-, methanol-, formate-,
O
-methyl-, or glucose-dependent growth. Protein profiles of oxalate-grown cells were dissimilar from protein profiles of glyoxylate-, CO-, or formate-grown cells, suggesting induction of new proteins for the utilization of oxalate.
C. thermoaceticum
DSM 2955 and
Clostridium thermoautotrophicum
JW 701/3 also grew at the expense of oxalate and glyoxylate. However, oxalate and glyoxylate did not support the growth of
C. thermoaceticum
OMD (a nonautotrophic strain) or six other species of acetogenic bacteria tested.
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Affiliation(s)
- S L Daniel
- Lehrstuhl für Okologische Mikrobiologie, BITOK, Universität Bayreuth, D-95440 Bayreuth, Germany
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30
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Kamlage B, Blaut M. Isolation of a cytochrome-deficient mutant strain of Sporomusa sphaeroides not capable of oxidizing methyl groups. J Bacteriol 1993; 175:3043-50. [PMID: 8491723 PMCID: PMC204624 DOI: 10.1128/jb.175.10.3043-3050.1993] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The homoacetogenic anaerobic bacterium Sporomusa sphaeroides was mutagenized with UV light. Taking advantage of the ampicillin enrichment technique and a newly developed test for the detection of heme in bacterial colonies, the cytochrome-deficient mutant strain S. sphaeroides BK824 was isolated. In contrast to the wild type, this mutant strain failed to grow on betaine, betaine plus methanol, H2 plus CO2, and methanol plus CO2. Growth on betaine plus formate, betaine plus H2, betaine plus pyruvate, methanol plus H2 and CO2, and acetoin was not impaired. All enzymes of the Wood pathway as well as hydrogenase and carbon monoxide dehydrogenase were detectable at comparable activities in both the wild type and the cytochrome-deficient mutant. Labeling experiments with [14C]methanol demonstrated the inability of S. sphaeroides BK824 to oxidize methyl groups. The role of cytochromes in electron transport steps associated with the Wood pathway enzymes and their possible role in energy conservation during autotrophic growth in acetogens are discussed.
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Affiliation(s)
- B Kamlage
- Institut für Mikrobiologie, Georg-August-Universität Göttingen, Federal Republic of Germany
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31
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Chapter 4 Bioenergetics and transport in methanogens and related thermophilic archaea. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/s0167-7306(08)60253-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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32
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Berman MH, Frazer AC. Importance of tetrahydrofolate and ATP in the anaerobic O-demethylation reaction for phenylmethylethers. Appl Environ Microbiol 1992; 58:925-31. [PMID: 1575495 PMCID: PMC195357 DOI: 10.1128/aem.58.3.925-931.1992] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
DL-Tetrahydrofolate (THF) and ATP were necessary for the anaerobic O-demethylation of phenylmethylethers in cell extracts of the type strain (ATCC 29683) of the homoacetogen Acetobacterium woodii. The reactants for this enzymatic activity have not been previously demonstrated in any system, nor has the mediating enzyme been studied. An assay using reaction mixtures containing 1 mM THF, 2 mM ATP, and 2 mM hydroferulate (i.e., 4-hydroxy,3-methoxyphenylpropionate) was developed and was performed under stringent anaerobic conditions. Pyridine nucleotides and several other possible cofactors were tested but had no effect on the activity. After centrifugation of disrupted cells at 27,000 x g, the activity was found primarily in the supernatant, which had a specific activity of 14.2 +/- 0.5 nmol/min/mg of protein. At saturating levels of each of the other two substrates, apparent Km values for the variable substrate were 0.65 mM hydroferulate, 0.27 mM ATP, and 0.17 mM THF. Activity was significantly decreased when extract was preincubated at 60 degrees C and was completely lost after preincubation in air for 30 min. Thus, the soluble anaerobic O-demethylating enzyme system of A. woodii is oxygen sensitive. The THF- and ATP-dependent activity measurable in the soluble fraction of cell extracts constituted about 34% of the activity seen with intact cells.
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Affiliation(s)
- M H Berman
- Department of Microbiology, New York University Medical Center, New York 10016
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33
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Cammack R. Iron—Sulfur Clusters in Enzymes: Themes and Variations. ADVANCES IN INORGANIC CHEMISTRY 1992. [DOI: 10.1016/s0898-8838(08)60066-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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34
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Novel Iron—Sulfur Centers in Metalloenzymes and Redox Proteins from Extremely Thermophilic Bacteria. ADVANCES IN INORGANIC CHEMISTRY 1992. [DOI: 10.1016/s0898-8838(08)60068-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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35
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Heise R, Reidlinger J, Müller V, Gottschalk G. A sodium-stimulated ATP synthase in the acetogenic bacterium Acetobacterium woodii. FEBS Lett 1991; 295:119-22. [PMID: 1837273 DOI: 10.1016/0014-5793(91)81400-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Experiments with resting cells of Acetobacterium woodii were performed to elucidate the coupling ion used by the ATP synthase. A. woodii synthesized ATP in response to an artificial delta pH, indicating the presence of a proton-translocating ATPase. On the other hand, a delta pNa, as well as a proton diffusion potential, could serve as a driving force for ATP synthesis with the latter strictly dependent on Na+. These results are indicative for the presence of a Na(+)-translocating ATP synthase in A. woodii.
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Affiliation(s)
- R Heise
- Institut für Mikrobiologie der Universität, Göttingen, Germany
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