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Alternative Pathways of Acetogenic Ethanol and Methanol Degradation in the Thermophilic Anaerobe Thermacetogenium phaeum

Growth of the anaerobic thermophile Thermacetogenium phaeum with methanol, ethanol, ethanolamine, and acetate was investigated in axenic cultures and in syntrophic cultures with Methanothermobacter thermautotrophicus. Microcompartment genes were identified in the T. phaeum genome, and presence of mi...

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Autores principales: Keller, Anja, Schink, Bernhard, Müller, Nicolai
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6436200/
https://www.ncbi.nlm.nih.gov/pubmed/30949135
http://dx.doi.org/10.3389/fmicb.2019.00423
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author Keller, Anja
Schink, Bernhard
Müller, Nicolai
author_facet Keller, Anja
Schink, Bernhard
Müller, Nicolai
author_sort Keller, Anja
collection PubMed
description Growth of the anaerobic thermophile Thermacetogenium phaeum with methanol, ethanol, ethanolamine, and acetate was investigated in axenic cultures and in syntrophic cultures with Methanothermobacter thermautotrophicus. Microcompartment genes were identified in the T. phaeum genome, and presence of microcompartments was confirmed by transmission electron microscopy and proteome analysis. These genes were expressed only during growth with ethanolamine. Proteome data were compared after growth with all four substrates, and activities of key enzymes of the Wood–Ljungdahl pathway and of enzyme systems leading to production or degradation of acetaldehyde such as alcohol dehydrogenase, aldehyde:ferredoxin oxidoreductase, acetate kinase, and phosphate acetyltransferase were measured in cytoplasmic fractions. Accounting of fermentation stoichiometries and growth yields with all four substrates showed that ethanol and methanol oxidation follow the same stoichiometries as in Acetobacterium woodii. On the other hand, the pathways of ethanol and methanol degradations vary between both organisms. Growth yields of T. phaeum were substantially lower than reported for A. woodii. Since T. phaeum has no Rnf complex encoded in its genome, the mechanisms of ATP synthesis have to be different from those of A. woodii. In addition to the central degradation pathways also found in A. woodii, T. phaeum maintains enzyme systems that compensate for the absence of an Rnf-complex but which on the other hand cause a loss of energy. On the basis of our data, pathways of methanol and ethanol degradation in T. phaeum are discussed.
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spelling pubmed-64362002019-04-04 Alternative Pathways of Acetogenic Ethanol and Methanol Degradation in the Thermophilic Anaerobe Thermacetogenium phaeum Keller, Anja Schink, Bernhard Müller, Nicolai Front Microbiol Microbiology Growth of the anaerobic thermophile Thermacetogenium phaeum with methanol, ethanol, ethanolamine, and acetate was investigated in axenic cultures and in syntrophic cultures with Methanothermobacter thermautotrophicus. Microcompartment genes were identified in the T. phaeum genome, and presence of microcompartments was confirmed by transmission electron microscopy and proteome analysis. These genes were expressed only during growth with ethanolamine. Proteome data were compared after growth with all four substrates, and activities of key enzymes of the Wood–Ljungdahl pathway and of enzyme systems leading to production or degradation of acetaldehyde such as alcohol dehydrogenase, aldehyde:ferredoxin oxidoreductase, acetate kinase, and phosphate acetyltransferase were measured in cytoplasmic fractions. Accounting of fermentation stoichiometries and growth yields with all four substrates showed that ethanol and methanol oxidation follow the same stoichiometries as in Acetobacterium woodii. On the other hand, the pathways of ethanol and methanol degradations vary between both organisms. Growth yields of T. phaeum were substantially lower than reported for A. woodii. Since T. phaeum has no Rnf complex encoded in its genome, the mechanisms of ATP synthesis have to be different from those of A. woodii. In addition to the central degradation pathways also found in A. woodii, T. phaeum maintains enzyme systems that compensate for the absence of an Rnf-complex but which on the other hand cause a loss of energy. On the basis of our data, pathways of methanol and ethanol degradation in T. phaeum are discussed. Frontiers Media S.A. 2019-03-19 /pmc/articles/PMC6436200/ /pubmed/30949135 http://dx.doi.org/10.3389/fmicb.2019.00423 Text en Copyright © 2019 Keller, Schink and Müller. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Microbiology
Keller, Anja
Schink, Bernhard
Müller, Nicolai
Alternative Pathways of Acetogenic Ethanol and Methanol Degradation in the Thermophilic Anaerobe Thermacetogenium phaeum
title Alternative Pathways of Acetogenic Ethanol and Methanol Degradation in the Thermophilic Anaerobe Thermacetogenium phaeum
title_full Alternative Pathways of Acetogenic Ethanol and Methanol Degradation in the Thermophilic Anaerobe Thermacetogenium phaeum
title_fullStr Alternative Pathways of Acetogenic Ethanol and Methanol Degradation in the Thermophilic Anaerobe Thermacetogenium phaeum
title_full_unstemmed Alternative Pathways of Acetogenic Ethanol and Methanol Degradation in the Thermophilic Anaerobe Thermacetogenium phaeum
title_short Alternative Pathways of Acetogenic Ethanol and Methanol Degradation in the Thermophilic Anaerobe Thermacetogenium phaeum
title_sort alternative pathways of acetogenic ethanol and methanol degradation in the thermophilic anaerobe thermacetogenium phaeum
topic Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6436200/
https://www.ncbi.nlm.nih.gov/pubmed/30949135
http://dx.doi.org/10.3389/fmicb.2019.00423
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