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Trace Elements Induce Predominance among Methanogenic Activity in Anaerobic Digestion
Trace elements (TE) play an essential role in all organisms due to their functions in enzyme complexes. In anaerobic digesters, control, and supplementation of TEs lead to stable and more efficient methane production processes while TE deficits cause process imbalances. However, the underlying metab...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5160323/ https://www.ncbi.nlm.nih.gov/pubmed/28018337 http://dx.doi.org/10.3389/fmicb.2016.02034 |
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author | Wintsche, Babett Glaser, Karin Sträuber, Heike Centler, Florian Liebetrau, Jan Harms, Hauke Kleinsteuber, Sabine |
author_facet | Wintsche, Babett Glaser, Karin Sträuber, Heike Centler, Florian Liebetrau, Jan Harms, Hauke Kleinsteuber, Sabine |
author_sort | Wintsche, Babett |
collection | PubMed |
description | Trace elements (TE) play an essential role in all organisms due to their functions in enzyme complexes. In anaerobic digesters, control, and supplementation of TEs lead to stable and more efficient methane production processes while TE deficits cause process imbalances. However, the underlying metabolic mechanisms and the adaptation of the affected microbial communities to such deficits are not yet fully understood. Here, we investigated the microbial community dynamics and resulting process changes induced by TE deprivation. Two identical lab-scale continuous stirred tank reactors fed with distiller’s grains and supplemented with TEs (cobalt, molybdenum, nickel, tungsten) and a commercial iron additive were operated in parallel. After 72 weeks of identical operation, the feeding regime of one reactor was changed by omitting TE supplements and reducing the amount of iron additive. Both reactors were operated for further 21 weeks. Various process parameters (biogas production and composition, total solids and volatile solids, TE concentration, volatile fatty acids, total ammonium nitrogen, total organic acids/alkalinity ratio, and pH) and the composition and activity of the microbial communities were monitored over the total experimental time. While the methane yield remained stable, the concentrations of hydrogen sulfide, total ammonia nitrogen, and acetate increased in the TE-depleted reactor compared to the well-supplied control reactor. Methanosarcina and Methanoculleus dominated the methanogenic communities in both reactors. However, the activity ratio of these two genera was shown to depend on TE supplementation explainable by different TE requirements of their energy conservation systems. Methanosarcina dominated the well-supplied anaerobic digester, pointing to acetoclastic methanogenesis as the dominant methanogenic pathway. Under TE deprivation, Methanoculleus and thus hydrogenotrophic methanogenesis was favored although Methanosarcina was not overgrown by Methanoculleus. Multivariate statistics revealed that the decline of nickel, cobalt, molybdenum, tungsten, and manganese most strongly influenced the balance of mcrA transcripts from both genera. Hydrogenotrophic methanogens seem to be favored under nickel- and cobalt-deficient conditions as their metabolism requires less nickel-dependent enzymes and corrinoid cofactors than the acetoclastic and methylotrophic pathways. Thus, TE supply is critical to sustain the activity of the versatile high-performance methanogen Methanosarcina. |
format | Online Article Text |
id | pubmed-5160323 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-51603232016-12-23 Trace Elements Induce Predominance among Methanogenic Activity in Anaerobic Digestion Wintsche, Babett Glaser, Karin Sträuber, Heike Centler, Florian Liebetrau, Jan Harms, Hauke Kleinsteuber, Sabine Front Microbiol Microbiology Trace elements (TE) play an essential role in all organisms due to their functions in enzyme complexes. In anaerobic digesters, control, and supplementation of TEs lead to stable and more efficient methane production processes while TE deficits cause process imbalances. However, the underlying metabolic mechanisms and the adaptation of the affected microbial communities to such deficits are not yet fully understood. Here, we investigated the microbial community dynamics and resulting process changes induced by TE deprivation. Two identical lab-scale continuous stirred tank reactors fed with distiller’s grains and supplemented with TEs (cobalt, molybdenum, nickel, tungsten) and a commercial iron additive were operated in parallel. After 72 weeks of identical operation, the feeding regime of one reactor was changed by omitting TE supplements and reducing the amount of iron additive. Both reactors were operated for further 21 weeks. Various process parameters (biogas production and composition, total solids and volatile solids, TE concentration, volatile fatty acids, total ammonium nitrogen, total organic acids/alkalinity ratio, and pH) and the composition and activity of the microbial communities were monitored over the total experimental time. While the methane yield remained stable, the concentrations of hydrogen sulfide, total ammonia nitrogen, and acetate increased in the TE-depleted reactor compared to the well-supplied control reactor. Methanosarcina and Methanoculleus dominated the methanogenic communities in both reactors. However, the activity ratio of these two genera was shown to depend on TE supplementation explainable by different TE requirements of their energy conservation systems. Methanosarcina dominated the well-supplied anaerobic digester, pointing to acetoclastic methanogenesis as the dominant methanogenic pathway. Under TE deprivation, Methanoculleus and thus hydrogenotrophic methanogenesis was favored although Methanosarcina was not overgrown by Methanoculleus. Multivariate statistics revealed that the decline of nickel, cobalt, molybdenum, tungsten, and manganese most strongly influenced the balance of mcrA transcripts from both genera. Hydrogenotrophic methanogens seem to be favored under nickel- and cobalt-deficient conditions as their metabolism requires less nickel-dependent enzymes and corrinoid cofactors than the acetoclastic and methylotrophic pathways. Thus, TE supply is critical to sustain the activity of the versatile high-performance methanogen Methanosarcina. Frontiers Media S.A. 2016-12-16 /pmc/articles/PMC5160323/ /pubmed/28018337 http://dx.doi.org/10.3389/fmicb.2016.02034 Text en Copyright © 2016 Wintsche, Glaser, Sträuber, Centler, Liebetrau, Harms and Kleinsteuber. 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) or licensor 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 Wintsche, Babett Glaser, Karin Sträuber, Heike Centler, Florian Liebetrau, Jan Harms, Hauke Kleinsteuber, Sabine Trace Elements Induce Predominance among Methanogenic Activity in Anaerobic Digestion |
title | Trace Elements Induce Predominance among Methanogenic Activity in Anaerobic Digestion |
title_full | Trace Elements Induce Predominance among Methanogenic Activity in Anaerobic Digestion |
title_fullStr | Trace Elements Induce Predominance among Methanogenic Activity in Anaerobic Digestion |
title_full_unstemmed | Trace Elements Induce Predominance among Methanogenic Activity in Anaerobic Digestion |
title_short | Trace Elements Induce Predominance among Methanogenic Activity in Anaerobic Digestion |
title_sort | trace elements induce predominance among methanogenic activity in anaerobic digestion |
topic | Microbiology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5160323/ https://www.ncbi.nlm.nih.gov/pubmed/28018337 http://dx.doi.org/10.3389/fmicb.2016.02034 |
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