Supercooled, subzero, high salinity incubations of Cp34H reveal long-term mitigation strategies and detectable (peptide) biomarkers for life on other icy worlds

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 simultaneous adaptations to high salinity and low temperature to survive, be metabolically active, or grow in the ice. Here we report results obtained through an experimental design that allowed us to monitor culturability, activity, and proteomic signatures of Colwellia psychrerythraea strain 34H (Cp34H) to subzero temperature, salinity, and nutrient availability by performing long-term incubations in eight different conditions. Shotgun proteomics revealed novel metabolic strategies used to maintain culturability in response to each independent experimental variable, particularly in pathways regulating carbon, nitrogen, and fatty acid metabolism. For the first time, statistical analysis of differential abundances of proteins uniquely identified in these 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 enriched and retained in -10oC incubations for four months identified over 400 potential biosignatures that could indicate the presence of terrestrial-like cold-active or halophilic metabolisms on other icy worlds.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Colwellia Psychrerythraea 34h

TISSUE(S): Cell Culture

SUBMITTER: Miranda Mudge  

LAB HEAD: Brook Nunn

PROVIDER: PXD022428 | Pride | 2022-02-16

REPOSITORIES: Pride