"Microbial diversity and activity in Southern California salterns and b" by Benjamin Klempay, Nestor Arandia-Gorostidi et al.

Faculty Publications

Title

Microbial diversity and activity in Southern California salterns and bitterns: analogues for remnant ocean worlds

Authors

Benjamin Klempay, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92037, USA.
Nestor Arandia-Gorostidi, Department of Earth System Science, Stanford University, Stanford, CA, 94305, USA.
Anne E. Dekas, Department of Earth System Science, Stanford University, Stanford, CA, 94305, USA.
Douglas H. Bartlett, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92037, USA.
Christopher E. Carr, Daniel Guggenheim School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Peter T. Doran, Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA, 70803, USA.
Avishek Dutta, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92037, USA.
Natalia Erazo, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92037, USA.
Luke A. Fisher, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92037, USA.
Jennifer B. Glass, School of Earth and Atmospheric Studies, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Alexandra Pontefract, Department of Biology, Georgetown University, Washington, DC, 20057, USA.
Sanjoy M. Som, Blue Marble Space Institute of Science, Seattle, WA, 98154, USA.

Document Type

Article

Publication Date

7-1-2021

Abstract

Concurrent osmotic and chaotropic stress make MgCl -rich brines extremely inhospitable environments. Understanding the limits of life in these brines is essential to the search for extraterrestrial life on contemporary and relict ocean worlds, like Mars, which could host similar environments. We sequenced environmental 16S rRNA genes and quantified microbial activity across a broad range of salinity and chaotropicity at a Mars-analogue salt harvesting facility in Southern California, where seawater is evaporated in a series of ponds ranging from kosmotropic NaCl brines to highly chaotropic MgCl brines. Within NaCl brines, we observed a proliferation of specialized halophilic Euryarchaeota, which corresponded closely with the dominant taxa found in salterns around the world. These communities were characterized by very slow growth rates and high biomass accumulation. As salinity and chaotropicity increased, we found that the MgCl -rich brines eventually exceeded the limits of microbial activity. We found evidence that exogenous genetic material is preserved in these chaotropic brines, producing an unexpected increase in diversity in the presumably sterile MgCl -saturated brines. Because of their high potential for biomarker preservation, chaotropic brines could therefore serve as repositories of genetic biomarkers from nearby environments (both on Earth and beyond) making them prime targets for future life-detection missions.

Publication Source (Journal or Book title)

Environmental microbiology

First Page

3825

Last Page

3839

Recommended Citation

Klempay, B., Arandia-Gorostidi, N., Dekas, A. E., Bartlett, D. H., Carr, C. E., Doran, P. T., Dutta, A., Erazo, N., Fisher, L. A., Glass, J. B., Pontefract, A., & Som, S. M. (2021). Microbial diversity and activity in Southern California salterns and bitterns: analogues for remnant ocean worlds. Environmental microbiology, 23 (7), 3825-3839. https://doi.org/10.1111/1462-2920.15440

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