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Hackstein JHP, de Graaf RM, van Hellemond JJ, Tielens AGM. Hydrogenosomes of Anaerobic Ciliates. ACTA ACUST UNITED AC 2019. [DOI: 10.1007/978-3-030-17941-0_5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
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Belanche A, de la Fuente G, Newbold CJ. Effect of progressive inoculation of fauna-free sheep with holotrich protozoa and total-fauna on rumen fermentation, microbial diversity and methane emissions. FEMS Microbiol Ecol 2014; 91:fiu026. [PMID: 25764558 PMCID: PMC4399445 DOI: 10.1093/femsec/fiu026] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Rumen methanogenesis represents an energy waste for the ruminant and an important source of greenhouse gas; thus, integrated studies are needed to fully understand this process. Eight fauna-free sheep were used to investigate the effect of successive inoculation with holotrich protozoa then with total fauna on rumen methanogenesis. Holotrichs inoculation neither altered rumen fermentation rate nor diet digestibility, but increased concentrations of acetate (+15%), butyrate (+57%), anaerobic fungi (+0.82 log), methanogens (+0.41 log) and methanogenesis (+54%). Further inoculation with total fauna increased rumen concentrations of protozoa (+1.0 log), bacteria (+0.29 log), anaerobic fungi (+0.78 log), VFA (+8%), ammonia and fibre digestibility (+17%) without affecting levels of methanogens or methanogenesis. Rumen methanogens population was fairly stable in terms of structure and diversity, while the bacterial community was highly affected by the treatments. Inoculation with holotrich protozoa increased bacterial diversity. Further inoculation with total fauna lowered bacterial diversity but increased concentrations of certain propionate and lactate-producing bacteria, suggesting that alternative H2 sinks could be relevant. This experiment suggests that holotrich protozoa have a greater impact on rumen methanogenesis than entodiniomorphids. Thus, further research is warranted to understand the effect of holotrich protozoa on methane formation and evaluate their elimination from the rumen as a potential methane mitigation strategy.
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Affiliation(s)
- Alejandro Belanche
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, Ceredigion SY23 3DB, UK
| | - Gabriel de la Fuente
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, Ceredigion SY23 3DB, UK
| | - Charles J Newbold
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, Ceredigion SY23 3DB, UK
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Abstract
Anaerobic ciliates are incapable of using oxidative phosphorylation in their energy metabolism and they are more or less sensitive to oxygen. All anaerobic ciliates possess mitochondria-like organelles (with a double outer membrane and often a few cristae) but these do not contain typical mitochondrial enzymes (e.g., cytochromes, cytochrome oxidase). In some species these organelles are capable of fermenting pyruvate into acetate and H2 and they are then referred to as hydrogenosomes. At least six orders of ciliates include anaerobic species. It is concluded that the evolution of anaerobic forms has taken place independently within different taxonomic groups and that hydrogenosomes are modified mitochondria. Many anaerobic ciliates harbour ecto- or endosymbiotic bacteria. Several ciliate species which produce hydrogen as a metabolic waste product harbour endosymbiotic methanogenic bacteria; in some cases this symbiosis represents a mutualistic relationship in which the host controls the life cycle of the symbionts and gains from their presence in terms of growth rate and growth efficiency. Many marine anaerobic ciliates harbour ectosymbiotic bacteria, but the nature of these bacteria and the significance of the association is not yet understood. The present paper reviews what is known about the biology of anaerobic ciliates with special emphasis on free-living forms, including a discussion of their habitats and their role in the microbial communities of anoxic environments.
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Affiliation(s)
- T Fenchel
- Marine Biological Laboratory, University of Copenhagen, Helsingør, Denmark
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Benchimol M. Hydrogenosomes under microscopy. Tissue Cell 2009; 41:151-68. [PMID: 19297000 DOI: 10.1016/j.tice.2009.01.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2008] [Revised: 01/04/2009] [Accepted: 01/13/2009] [Indexed: 11/19/2022]
Abstract
A hydrogenosome is a hydrogen-producing organelle, evolutionary related to mitochondria and is found in Parabasalia protozoa, certain chytrid fungi and certain ciliates. It displays similarities to and differences from mitochondria. Hydrogenosomes are spherical or slightly elongated organelles, although very elongated hydrogenosomes are also found. They measure from 200 nm to 1 microm, but under stress conditions can reach up to 2 microm. Hydrogenosomes are surrounded by two closely apposed membranes and present a granular matrix. Cardiolipin has been detected in their membranes, and frataxin, which is a conserved mitochondrial protein involved in iron metabolism, was also recently found. Hydrogenosomes have one or multiple peripheral vesicles, which incorporate calcium. The peripheral vesicle can be isolated from the hydrogenosomal matrix and can be considered as a distinct hydrogenosomal compartment. Dysfunctional hydrogenosomes can be removed by an autophagic process and further digested by lysosomes. Hydrogenosomes divide in three different ways, like mitochondria, by segmentation, partition and the heart form. They may divide at any phase of the cell cycle. Nucleoid or electron dense deposits found in hydrogenosomes can be considered artifacts or dysfunctional hydrogenosomes. The hydrogenosome does not contain a genome, although DNA has already been detected in one anaerobic ciliate. Hydrogenosomes can be considered as good drug targets since their metabolism is distinct from mitochondria.
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Affiliation(s)
- Marlene Benchimol
- Universidade Santa Ursula, Laboratório de Ultraestrutura Celular, Rio de Janeiro, Brazil.
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Hydrogenosomes of Anaerobic Ciliates. HYDROGENOSOMES AND MITOSOMES: MITOCHONDRIA OF ANAEROBIC EUKARYOTES 2008. [DOI: 10.1007/7171_2007_109] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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LEE JOHNJ, SOLDO ANTHONYT, REISSER WERNER, LEE MONICAJ, JEON KW, GÖRTZ HANSDIETER. The Extent of Algal and Bacterial Endosymbioses in Protozoa1,2. ACTA ACUST UNITED AC 2007. [DOI: 10.1111/j.1550-7408.1985.tb04034.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Plümper E, Bradley PJ, Johnson PJ. Competition and protease sensitivity assays provide evidence for the existence of a hydrogenosomal protein import machinery in Trichomonas vaginalis. Mol Biochem Parasitol 2000; 106:11-20. [PMID: 10743607 DOI: 10.1016/s0166-6851(99)00196-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Hydrogenosomes are double membrane bounded redox organelles found in a number of amitochondriate protists and fungi. They are involved in carbohydrate metabolism and ATP synthesis and thus resemble mitochondria. Molecular analysis of the hydrogenosomal heat shock proteins Hsp70, Hsp60 and Hsp10 in Trichomonas vaginalis, one of the deepest-branching eukaryotes known to date, has revealed that these group exclusively with mitochondrial heat shock proteins. This finding indicates strongly that a progenitor organelle which gave rise to contemporary mitochondria and hydrogenosomes existed early in eukaryotic life. This hypothesis is further supported by similarities of hydrogenosomal and mitochondrial biogenesis. It was shown that T. vaginalis hydrogenosomal proteins are synthesized on free ribosomes in the cytosol with an N-terminal presequence that carries targeting information and is cleaved upon import into the organelle. Furthermore, as in mitochondrial import, hydrogenosomal protein import requires ATP, an electrochemical transmembrane potential and cytosolic protein factor(s). Here we demonstrate that inhibition of hydrogenosomal protein import occurs (i) in the presence of a synthetic presequence peptide and (ii) after pretreatment of hydrogenosomes with the protease trypsin. Trypsin pretreatment affects two hydrogenosomal membrane proteins of 31 and 70 kDa, respectively. Thus, we present evidence that import is saturable and that proteinaceous hydrogenosomal import receptor(s) exist. These results are a first step towards a characterization of the hydrogenosomal import machinery which should provide further insights into the relationship of hydrogenosomes and mitochondria and the evolution of protein targeting into organelles of endosymbiotic origin.
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Affiliation(s)
- E Plümper
- Department of Microbiology and Immunology, University of California, Los Angeles 90095-1489, USA
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Benchimol M, Durand R, Almeida JC. A double membrane surrounds the hydrogenosomes of the anaerobic fungus Neocallimastix frontalis. FEMS Microbiol Lett 1997; 154:277-82. [PMID: 9311125 DOI: 10.1111/j.1574-6968.1997.tb12656.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The structure of hydrogenosomes of the anaerobic fungus Neocallimastix frontalis was analyzed using routine preparations for transmission electron microscopy, freeze-fracture and immunocytochemistry. They appeared as round or elongated structures, always enveloped by two distinct, but tightly apposed membranes. Images of organelle division were very similar to those observed in trichomonad protozoa. These observations suggest that hydrogenosomes are homologous organelles in unrelated species weakening the hypothesis of a polyphyletic origin and supporting the evidence that fungal hydrogenosomes are probably derived from an endosymbiont relationship.
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Affiliation(s)
- M Benchimol
- Laboratòrio de Biologia Celular e Tecidual, Universidade Estadual do Norte Fluminense, Rio de Janeiro, Brazil.
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Benchimol M, Almeida JC, de Souza W. Further studies on the organization of the hydrogenosome in Tritrichomonas foetus. Tissue Cell 1996; 28:287-99. [PMID: 8701434 DOI: 10.1016/s0040-8166(96)80016-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The fine structure of the hydrogenosome of Tritrichomonas foetus was analysed using different approaches: routine transmission electron microscopy, quick-freezing techniques followed by freeze-fracture, deep-etching and freeze-substitution, cryo-ultramicrotomy, serial sectioning followed by three-dimensional (3D) reconstruction and cytochemical detection of carbohydrates, Ca++ and phosphates. The presence of two closely apposed unit membranes surrounding the hydrogenosome, as well as its internal vesicle, was shown both in thin sections of well-preserved cells and in freeze-fracture replicas. Analysis of light micrographs, thin serial sections used to 3-D reconstruction and freeze-fracture replicas, show that the hydrogenosome of T. foetus resembles a sphere, but presents a protusion towards the cytoplasm. The vesicle varies in size from organelle to organelle and represent about 8.5% of the volume of the organelle. Based on the fact that the vesicle (a) presents a distinct morphological appearance from the hydrogenosome matrix, (b) was the main site of Ca++-accumulation, (c) presents phosphatase activity and (d) its membrane presents N-acetyl-glucosamine-containing glycoconjugates, as revealed by incubation of cryosections in the presence of gold-labeled WGA, we conclude that it represents a specialized sub-compartment of the hydrogenosome. Freeze-fracture followed by deep etching showed the presence of large number of particles, probably correspondent to macromolecules, within the hydrogenosomal matrix. These structures were not randomly distributed.
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Affiliation(s)
- M Benchimol
- Laboratório de Biologia Cellular e Tecidual, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense, Rio de Janeiro, Brazil
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Marvin-Sikkema FD, Pedro Gomes TM, Grivet JP, Gottschal JC, Prins RA. Characterization of hydrogenosomes and their role in glucose metabolism of Neocallimastix sp. L2. Arch Microbiol 1993; 160:388-96. [PMID: 8257282 DOI: 10.1007/bf00252226] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In the anaerobic fungus Neocallimastix sp. L2 fermentation of glucose proceeds via the Embden-Meyerhof-Parnas pathway. Enzyme activities leading to the formation of succinate, lactate, ethanol, and formate are associated with the cytoplasmic fraction. The enzymes 'malic enzyme,' NAD(P)H:ferredoxin oxidoreductase, pyruvate:ferredoxin oxidoreductase, hydrogenase, acetate:succinate CoA transferase and succinate thiokinase leading to the formation of H2,CO2, acetate, and ATP are localized in microbodies. Thus, these organelles are identified as hydrogenosomes. In addition, the microbodies contain the O2-scavenging enzymes NADH- and NADPH oxidase, while NAD(P)H peroxidase, catalase, or superoxide dismutase could not be detected. In cell-free extracts from zoospores of Neocallimastix sp. L2 the specific activities of hydrogenosomal enzymes as well as the quantities of these proteins are 2- to 6-fold higher than in mycelium extracts. These findings suggest that hydrogenosomes perform an important role--especially in zoospores--as H2-evolving, ATP-generating and O2-scavenging organelles.
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Gordon Paul R, Butler RD, Williams AG. Ultrastructure of the rumen ciliate Dasytricha ruminantium. Eur J Protistol 1989. [DOI: 10.1016/s0932-4739(89)80057-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Yarlett N, Rowlands C, Evans JC, Lloyd D. Respiration of the hydrogenosome-containing fungus Neocallimastix patriciarum. Arch Microbiol 1987. [DOI: 10.1007/bf00429642] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Yarlett N, Orpin CG, Munn EA, Yarlett NC, Greenwood CA. Hydrogenosomes in the rumen fungus Neocallimastix patriciarum. Biochem J 1986; 236:729-39. [PMID: 3539104 PMCID: PMC1146905 DOI: 10.1042/bj2360729] [Citation(s) in RCA: 157] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Sedimentable hydrogenase activity was demonstrated in cell-free extracts from both zoospores and vegetative growth of the anaerobic rumen fungus Neocallimastix patriciarum. Electron micrographs of the fraction enriched in hydrogenase activity contained finely granular microbody-like organelles, about 0.5 micron in diameter and having an equilibrium density of about 1.2 g X ml-1 in sucrose, 1.12 g X ml-1 in Percoll and 1.27-1.28 g X ml-1 in Metrizamide. These organelles, which are sedimentable at 10(5) g-min, bear no similarity to mitochondria, but are morphologically similar to hydrogen-evolving organelles possessed by certain anaerobic protozoa and termed 'hydrogenosomes'. Other typical hydrogenosomal enzymes, namely 'malic' enzyme, pyruvate:ferredoxin oxidoreductase and NADPH:ferredoxin oxidoreductase, were enriched in the same particle fraction as hydrogenase. The synthesis of pyruvate:ferredoxin oxidoreductase was found to be suppressed when the organism was cultured under an atmosphere of CO2, and an alternative pathway is proposed for growth under these conditions.
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Yarlett N, Lloyd D, Williams AG. Butyrate formation from glucose by the rumen protozoon Dasytricha ruminantium. Biochem J 1985; 228:187-92. [PMID: 3924032 PMCID: PMC1144968 DOI: 10.1042/bj2280187] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Production of butyrate by the holotrich protozoon Dasytricha ruminantium involves the enzymes of glycolysis, pyruvate:ferredoxin oxidoreductase, acetyl-CoA:acetyl-CoA C-acetyltransferase, 3-hydroxybutyryl-CoA dehydrogenase, 3-hydroxyacyl-CoA hydro-lyase, 3-hydroxyacyl-CoA reductase, phosphate butyryltransferase and butyrate kinase. Subcellular fractionation by differential and density-gradient centrifugation on sucrose gradients indicated that all those enzymes except pyruvate:ferredoxin oxidoreductase were non-sedimentable at 6 X 10(6) g-min. Butyrate kinase and phosphate butyryltransferase were associated with the large- and small-granule fractions. Thus, although metabolic reactions necessary for butyrate production proceed predominantly in the cytosol, hydrogenosomes play a key role in the conversion of pyruvate into acetyl-CoA.
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Yarlett N, Coleman GS, Williams AG, Lloyd D. Hydrogenosomes in known species of rumen entodiniomorphid protozoa. FEMS Microbiol Lett 1984. [DOI: 10.1111/j.1574-6968.1984.tb00178.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Yarlett N, Hann AC, Lloyd D, Williams AG. Hydrogenosomes in a mixed isolate of Isotricha prostoma and Isotricha intestinalis from ovine rumen contents. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1983; 74:357-64. [PMID: 6403285 DOI: 10.1016/0305-0491(83)90025-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
1. Both Isotricha intestinalis and I. prostoma possess microbody-like organelles, with a highly granular appearance. 2. These organelles, which are sedimentable at 10(5) g-min, bear no morphological similarity to mitochondria, but are enzymatically similar to organelles possessed by certain other anaerobic protozoa and termed hydrogenosomes. 3. The hydrogenosomes isolated from a preparation of mixed isotrichs bear a closer similarity to those isolated from the other rumen holotrich. Dasytricha ruminantium, than those recently identified in a mixed entodiniomorph preparation, or the trichomonads, in that the enzyme malate dehydrogenase (decarboxylating) is non-sedimentable and phosphoacetyl transferase together with acetate kinase are involved in the transformation of acetyl CoA to acetate. 4. The results enable a scheme of acetate, CO2 and H2 formation from carbohydrates to be proposed and extends the number of protozoa known to possess this organelle.
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