Life trapped in ice: Microbial survival and activity within melted brines in layered ices relevant to mars
Date
2022-04-15Author
Janes, Logan
Schneegurt, Mark A.
Advisor
Schneegurt, Mark A.Metadata
Show full item recordCitation
Janes, Logan; Schneegurt, Mark A.. 2022.
Life trapped in ice: Microbial survival and activity within melted brines in layered ices relevant to mars -- In Proceedings: 21st Annual Undergraduate Research and Creative Activity Forum. Wichita, KS: Wichita State University, p. 27
Abstract
Mars is a prime candidate for supporting living systems. Since liquid water is
rare, Martian life might exist inside brine near the surface trapped between layers of pure
water ice from frost and aeolian regolith deposits. Our lab examines whether
salinotolerant bacteria including Marinococcus sp. str. HL11, Halomonas sp. str. BLE7,
and Halomonas sp. str. GSP3 can survive and metabolize under artificial Martian
conditions. The configuration that might best mimic natural Mars ices is ice lenses where
pockets of bacterial cultures are entirely surrounded by pure water ice. We hope liquid
culture encased in ice will prevent edge effects from containers. The ice lenses are
created by freezing a layer of pure water with a central depression. Salty bacterial
cultures are frozen in this well and pure water is frozen as a top layer. The salty culture
melts at a lower temperature than the surrounding ice, so experiments can be performed
with liquid culture encased in ice. A culture lens at 15% NaCl will melt at -12 °C, while
the water ice layers remain frozen. We are working to understand how cells respond to
entrapment inside the brine lens, including performing assays with XTT to study
respiration and measuring survival rates with dilution plating. We believe that cells settle
inside the lens and create a biofilm. This project will inform the search for life on Mars
by identifying suitable habitats to target and contribute to planetary protection protocols
by characterizing the limits of life. Funded by NASA and FYRE.
Description
Presented to the 21st Undergraduate Research and Creative Activity Forum (URCAF) held at the Rhatigan Student Center, Wichita State University, April 15, 2022.