Metabolic Activities and Gene Expression of Marine Psychrophiles in Cold Ice

PI: Karen Junge

The mechanisms enabling bacteria to be metabolically active at very low temperatures are of considerable importance to polar microbial ecology, astrobiology, climate and cryopreservation, yet the true nature of these mechanisms remains elusive. This research program has two main objectives. The first is to investigate metabolic activities and protein expression of polar marine psychrophilic bacteria when confronted with freezing conditions at temperatures above the eutectic of seawater (–54°C) to unveil cold adaptation mechanisms with relevance to wintertime sea-ice ecology. The second objective is to discern, if psychrophilic processes of leucine incorporation into proteins, shown to occur to –196°C (Junge et al. 2006, Discover Magazine 2015 article), amount to metabolic activity providing for the survival of cells or are merely biochemical reactions still possible in flash-frozen samples without any effect on survival. (New Scientist article).
Currently, we are exploring the relationship between this deep-freeze bacterial activity, proteomics, polymers and the physical state of the ice in collaboration with Brook Nunn from the Goodlet laboratory here at UW and Hajo Eicken at UAF. This collaboration puts us in a unique position to solve an incredible puzzle (i.e. if and how can life be active without liquid water being present) and will provide important keys to questions regarding life under extreme conditions, be it in the various ice formations here on Earth, the atmosphere or elsewhere in the universe.

Funding source: NSF- OPP grants 0338333, 0739783.

• Junge et al., 2006

• Junge et al., 2011

• Nunn et al., 2015