P059-08
Adenosine Triphosphate (ATP) Analysis to Understand Spatial Distribution of Terrestrial Biosignature's in Brine Pools as an Analog for Planetary Extant and Relic Oceans
Monday, 14 December 2020: 08:51
Virtual
Carlie Marie Novak1, Ellery D Ingall2, Jennifer B Glass3, Peter T Doran4,5, Nestor Arandia Gorostidi6, Anne E Dekas7, Alexandra Pontefract8, Sanjoy M Som9, Andrew Mullen10, Enrica Quartini11, Christopher E. Carr12, Madeline Myers13, Jeff Shovlowsky Bowman10,14, Britney Schmidt11 and Amanda M. Stockton15, (1)Georgia Institute of Technology, School of Chemistry and Biochemistry, Analytical Chemistry, Atlanta, GA, United States, (2)Georgia Tech, Atlanta, GA, United States, (3)Georgia Institute of Technology, Earth and Atmospheric Sciences, Atlanta, GA, United States, (4)Boulder, CO, United States, (5)Louisiana State University, Baton Rouge, LA, United States, (6)Stanford University, Earth System Sciences, Stanford, CA, United States, (7)Lawrence Livermore National Laboratory, Livermore, CA, United States, (8)Massachusetts Institute of Technology, Earth, Atmospheric and Planetary Sciences, Cambridge, MA, United States, (9)Blue Marble Space Institute of Science, Seattle, WA, United States, (10)Scripps Institution of Oceanography, La Jolla, CA, United States, (11)Georgia Institute of Technology, School of Earth and Atmospheric Sciences, Atlanta, GA, United States, (12)Georgia Institute of Technology, Atlanta, United States, (13)Louisiana State University, Department of Geology and Geophysics, Baton Rouge, LA, United States, (14)Columbia University, Lamont-Doherty Earth Observatory, Palisades, CA, United States, (15)Jet Propulsion Laboratory, Pasadena, CA, United States
Abstract:
While adenosine triphosphate (ATP) is an energy-storage molecule potentially not conserved across planetary environments, its ubiquity in terrestrial biology makes it attractive as a biomarker for terrestrial biota. Given the relative ease of analysis via a bioluminescence assay, many terrestrial analogue studies use ATP as a proxy biomarker to understand distribution and preservation of biomarkers in planetary analogue samples. In this study, we optimized the ATP bioluminescence assay for highly saline samples and examined the ATP content of several brine pools containing varying levels of sodium, magnesium, and chloride at South Bay Salt Works as an analogue for extant and relic oceans on solar system bodies like Mars and Europa.
Assay optimization and performance will be presented, including a high degree of linearity over three orders of magnitude and a lower limit of quantitation of 100-1000 pM depending on salt concentration. The assay is robust to Mg concentrations as high as 3 M, with higher concentrations requiring desalting prior to analysis.
Pools with higher brine content (> 4 M total NaCl and MgCl2) were found to have higher ATP contents than the pool with lower total brine content (1.5 M total NaCl and MgCl2), indicative of the survival of more organisms to scavenge this molecule in the lower brine content pool and the organic biosignature preservative in higher brine concentrations. Comparison of brine samples filtered through 0.2 um filters and raw samples indicated that all samples had both extracellular and intracellular ATP, with the more saline pools having a greater ratio of extracellular to intracellular ATP. A study of spatially distributed sediment samples at the borders of the brine pools revealed significant sample heterogeneity, both within a single 50 mL sample and between samples spaced as close as 10 cm apart. Implications of these results for planning sample selection for in situ missions will be discussed.
