Arsenic metabolism in high altitude modern stromatolites revealed by metagenomic analysis

Modern stromatolites thrive only in selected locations in the world. Socompa Lake, located in the Andean plateau at 3570 masl, is one of the numerous extreme Andean microbial ecosystems described over recent years. Extreme environmental conditions include hypersalinity, high UV incidence, and high a...

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Detalhes bibliográficos
Autores: Kurth, Daniel German, Amadio, Ariel Fernando, Ordoñez, Omar Federico, Albarracín, Virginia Helena, Gärtner, Wolfgang, Farias, Maria Eugenia
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2017
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/63437
Acesso em linha:http://hdl.handle.net/11336/63437
Access Level:acceso abierto
Palavra-chave:METAGENOMICS
DNA SEQUENCING
MICROBIAL MATS
ARSENIC
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descrição
Resumo:Modern stromatolites thrive only in selected locations in the world. Socompa Lake, located in the Andean plateau at 3570 masl, is one of the numerous extreme Andean microbial ecosystems described over recent years. Extreme environmental conditions include hypersalinity, high UV incidence, and high arsenic content, among others. After Socompa's stromatolite microbial communities were analysed by metagenomic DNA sequencing, taxonomic classification showed dominance of Proteobacteria, Bacteroidetes and Firmicutes, and a remarkably high number of unclassified sequences. A functional analysis indicated that carbon fixation might occur not only by the Calvin-Benson cycle, but also through alternative pathways such as the reverse TCA cycle, and the reductive acetyl-CoA pathway. Deltaproteobacteria were involved both in sulfate reduction and nitrogen fixation. Significant differences were found when comparing the Socompa stromatolite metagenome to the Shark Bay (Australia) smooth mat metagenome: namely, those involving stress related processes, particularly, arsenic resistance. An in-depth analysis revealed a surprisingly diverse metabolism comprising all known types of As resistance and energy generating pathways. While the ars operon was the main mechanism, an important abundance of arsM genes was observed in selected phyla. The data resulting from this work will prove a cornerstone for further studies on this rare microbial community.