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Subzero, saline incubations of Colwellia psychrerythraea reveal strategies and biomarkers for sustained life in extreme icy environments

Authors :
Kianna Hales
Miranda C. Mudge
J. D. Toner
Karen Junge
Bonnie Light
Marcela Ewert
William E. Fondrie
Brook L. Nunn
William Stafford Noble
Erin Firth
Source :
Environ Microbiol
Publication Year :
2021
Publisher :
Wiley, 2021.

Abstract

Colwellia psychrerythraea is a marine psychrophilic bacterium known for its remarkable ability to maintain activity during long-term exposure to extreme subzero temperatures and correspondingly high salinities in sea ice. These microorganisms must have adaptations to both high salinity and low temperature to survive, be metabolically active, or grow in the ice. Here, we report on an experimental design that allowed us to monitor culturability, cell abundance, activity and proteomic signatures of C. psychrerythraea strain 34H (Cp34H) in subzero brines and supercooled sea water through long-term incubations under eight conditions with varying subzero temperatures, salinities and nutrient additions. Shotgun proteomics found novel metabolic strategies used to maintain culturability in response to each independent experimental variable, particularly in pathways regulating carbon, nitrogen and fatty acid metabolism. Statistical analysis of abundances of proteins uniquely identified in isolated conditions provide metabolism-specific protein biosignatures indicative of growth or survival in either increased salinity, decreased temperature, or nutrient limitation. Additionally, to aid in the search for extant life on other icy worlds, analysis of detected short peptides in −10°C incubations after 4 months identified over 500 potential biosignatures that could indicate the presence of terrestrial-like cold-active or halophilic metabolisms on other icy worlds.

Details

ISSN :
14622920 and 14622912
Volume :
23
Database :
OpenAIRE
Journal :
Environmental Microbiology
Accession number :
edsair.doi.dedup.....d8b8abfdfbbb660ad33744d0cd5f04de
Full Text :
https://doi.org/10.1111/1462-2920.15485