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Understanding the Response of Nitrifying Communities to Disturbance in the McMurdo Dry Valleys, Antarctica

Polar ecosystems are generally limited in nitrogen (N) nutrients, and the patchy availability of N is partly determined by biological pathways, such as nitrification, which are carried out by distinctive prokaryotic functional groups. The activity and diversity of microorganisms are generally strong...

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Autores principales: Monteiro, Maria, S. Baptista, Mafalda, Séneca, Joana, Torgo, Luís, K. Lee, Charles, Cary, S. Craig, Magalhães, Catarina
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7143839/
https://www.ncbi.nlm.nih.gov/pubmed/32183078
http://dx.doi.org/10.3390/microorganisms8030404
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author Monteiro, Maria
S. Baptista, Mafalda
Séneca, Joana
Torgo, Luís
K. Lee, Charles
Cary, S. Craig
Magalhães, Catarina
author_facet Monteiro, Maria
S. Baptista, Mafalda
Séneca, Joana
Torgo, Luís
K. Lee, Charles
Cary, S. Craig
Magalhães, Catarina
author_sort Monteiro, Maria
collection PubMed
description Polar ecosystems are generally limited in nitrogen (N) nutrients, and the patchy availability of N is partly determined by biological pathways, such as nitrification, which are carried out by distinctive prokaryotic functional groups. The activity and diversity of microorganisms are generally strongly influenced by environmental conditions. However, we know little of the attributes that control the distribution and activity of specific microbial functional groups, such as nitrifiers, in extreme cold environments and how they may respond to change. To ascertain relationships between soil geochemistry and the ecology of nitrifying microbial communities, we carried out a laboratory-based manipulative experiment to test the selective effect of key geochemical variables on the activity and abundance of ammonia-oxidizing communities in soils from the McMurdo Dry Valleys of Antarctica. We hypothesized that nitrifying communities, adapted to different environmental conditions within the Dry Valleys, will have distinct responses when submitted to similar geochemical disturbances. In order to test this hypothesis, soils from two geographically distant and geochemically divergent locations, Miers and Beacon Valleys, were incubated over 2 months under increased conductivity, ammonia concentration, copper concentration, and organic matter content. Amplicon sequencing of the 16S rRNA gene and transcripts allowed comparison of the response of ammonia-oxidizing Archaea (AOA) and ammonia-oxidizing Bacteria (AOB) to each treatment over time. This approach was combined with measurements of (15)NH(4)(+) oxidation rates using (15)N isotopic additions. Our results showed a higher potential for nitrification in Miers Valley, where environmental conditions are milder relative to Beacon Valley. AOA exhibited better adaptability to geochemical changes compared to AOB, particularly to the increase in copper and conductivity. AOA were also the only nitrifying group found in Beacon Valley soils. This laboratorial manipulative experiment provided new knowledge on how nitrifying groups respond to changes on key geochemical variables of Antarctic desert soils, and we believe these results offer new insights on the dynamics of N cycling in these ecosystems.
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spelling pubmed-71438392020-04-14 Understanding the Response of Nitrifying Communities to Disturbance in the McMurdo Dry Valleys, Antarctica Monteiro, Maria S. Baptista, Mafalda Séneca, Joana Torgo, Luís K. Lee, Charles Cary, S. Craig Magalhães, Catarina Microorganisms Article Polar ecosystems are generally limited in nitrogen (N) nutrients, and the patchy availability of N is partly determined by biological pathways, such as nitrification, which are carried out by distinctive prokaryotic functional groups. The activity and diversity of microorganisms are generally strongly influenced by environmental conditions. However, we know little of the attributes that control the distribution and activity of specific microbial functional groups, such as nitrifiers, in extreme cold environments and how they may respond to change. To ascertain relationships between soil geochemistry and the ecology of nitrifying microbial communities, we carried out a laboratory-based manipulative experiment to test the selective effect of key geochemical variables on the activity and abundance of ammonia-oxidizing communities in soils from the McMurdo Dry Valleys of Antarctica. We hypothesized that nitrifying communities, adapted to different environmental conditions within the Dry Valleys, will have distinct responses when submitted to similar geochemical disturbances. In order to test this hypothesis, soils from two geographically distant and geochemically divergent locations, Miers and Beacon Valleys, were incubated over 2 months under increased conductivity, ammonia concentration, copper concentration, and organic matter content. Amplicon sequencing of the 16S rRNA gene and transcripts allowed comparison of the response of ammonia-oxidizing Archaea (AOA) and ammonia-oxidizing Bacteria (AOB) to each treatment over time. This approach was combined with measurements of (15)NH(4)(+) oxidation rates using (15)N isotopic additions. Our results showed a higher potential for nitrification in Miers Valley, where environmental conditions are milder relative to Beacon Valley. AOA exhibited better adaptability to geochemical changes compared to AOB, particularly to the increase in copper and conductivity. AOA were also the only nitrifying group found in Beacon Valley soils. This laboratorial manipulative experiment provided new knowledge on how nitrifying groups respond to changes on key geochemical variables of Antarctic desert soils, and we believe these results offer new insights on the dynamics of N cycling in these ecosystems. MDPI 2020-03-13 /pmc/articles/PMC7143839/ /pubmed/32183078 http://dx.doi.org/10.3390/microorganisms8030404 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Monteiro, Maria
S. Baptista, Mafalda
Séneca, Joana
Torgo, Luís
K. Lee, Charles
Cary, S. Craig
Magalhães, Catarina
Understanding the Response of Nitrifying Communities to Disturbance in the McMurdo Dry Valleys, Antarctica
title Understanding the Response of Nitrifying Communities to Disturbance in the McMurdo Dry Valleys, Antarctica
title_full Understanding the Response of Nitrifying Communities to Disturbance in the McMurdo Dry Valleys, Antarctica
title_fullStr Understanding the Response of Nitrifying Communities to Disturbance in the McMurdo Dry Valleys, Antarctica
title_full_unstemmed Understanding the Response of Nitrifying Communities to Disturbance in the McMurdo Dry Valleys, Antarctica
title_short Understanding the Response of Nitrifying Communities to Disturbance in the McMurdo Dry Valleys, Antarctica
title_sort understanding the response of nitrifying communities to disturbance in the mcmurdo dry valleys, antarctica
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7143839/
https://www.ncbi.nlm.nih.gov/pubmed/32183078
http://dx.doi.org/10.3390/microorganisms8030404
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