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Finstad KM, Probst AJ, Thomas BC, Andersen GL, Demergasso C, Echeverría A, Amundson RG, Banfield JF. Microbial Community Structure and the Persistence of Cyanobacterial Populations in Salt Crusts of the Hyperarid Atacama Desert from Genome-Resolved Metagenomics. Front Microbiol 2017; 8:1435. [PMID: 28804480 PMCID: PMC5532433 DOI: 10.3389/fmicb.2017.01435] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 07/14/2017] [Indexed: 12/22/2022] Open
Abstract
Although once thought to be devoid of biology, recent studies have identified salt deposits as oases for life in the hyperarid Atacama Desert. To examine spatial patterns of microbial species and key nutrient sources, we genomically characterized 26 salt crusts from three sites along a fog gradient. The communities are dominated by a large variety of Halobacteriales and Bacteroidetes, plus a few algal and Cyanobacterial species. CRISPR locus analysis suggests the distribution of a single Cyanobacterial population among all sites. This is in stark contrast to the extremely high sample specificity of most other community members. Only present at the highest moisture site is a genomically characterized Thermoplasmatales archaeon (Marine Group II) and six Nanohaloarchaea, one of which is represented by a complete genome. Parcubacteria (OD1) and Saccharibacteria (TM7), not previously reported from hypersaline environments, were found at low abundances. We found no indication of a N2 fixation pathway in the communities, suggesting acquisition of bioavailable nitrogen from atmospherically derived nitrate. Samples cluster by site based on bacterial and archaeal abundance patterns and photosynthetic capacity decreases with increasing distance from the ocean. We conclude that moisture level, controlled by coastal fog intensity, is the strongest driver of community membership.
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Affiliation(s)
- Kari M. Finstad
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, BerkeleyCA, United States
| | - Alexander J. Probst
- Department of Earth and Planetary Sciences, University of California, Berkeley, BerkeleyCA, United States
| | - Brian C. Thomas
- Department of Earth and Planetary Sciences, University of California, Berkeley, BerkeleyCA, United States
| | - Gary L. Andersen
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, BerkeleyCA, United States
- Ecology Department, Earth Sciences Division, Lawrence Berkeley National Laboratory, BerkeleyCA, United States
| | - Cecilia Demergasso
- Centro de Biotecnología, Universidad Católica del NorteAntofagasta, Chile
| | - Alex Echeverría
- Centro de Biotecnología, Universidad Católica del NorteAntofagasta, Chile
| | - Ronald G. Amundson
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, BerkeleyCA, United States
| | - Jillian F. Banfield
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, BerkeleyCA, United States
- Department of Earth and Planetary Sciences, University of California, Berkeley, BerkeleyCA, United States
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