Understanding the habitability of subzero temperature environments

Congratulations to Dr Stewart Gault who has received a Royal Society of Edinburgh grant to support his research in understanding how bacteria survives at low temperatures.

The Small Research Grant from the Royal Society of Edinburgh (RSE) covers the costs arising from a defined research project and encourages high-quality research and academic innovation.

The limits of life

One of the major goals in astrobiology is discerning the limits to life and how life has adapted to extreme environments, thereby informing us as to whether extreme environments found beyond Earth are potentially capable of supporting life.

Understanding the habitability of subzero temperature environments is particularly important as the icy moons Europa and Enceladus contain vast quantities of liquid water. However, we do not know what the low temperature limit for life is, or whether it is set by one factor or a combination of factors.

Record holder

The current record holder for low temperature growth and metabolism is Planococcus halocryophilus (P. halocryophilus), which can replicate at -15°C, while maintaining metabolic activity down to -25°C. The mechanisms which facilitate this low temperature activity are currently unknown.

Research project

This RSE Grant will enable Dr Gault to investigate whether it is the onset of intracellular vitrification that enforces a limit for P. halocryophilus’ low temperature activity and whether P. halocryophilus has adaptations which can modulate its intracellular vitrification.

In addition, he will be exploring whether the presence of extracellular ions found in the natural environment and the growth medium confer any depression of P. halocryophilus’ intracellular vitrification, thereby permitting low temperature metabolic activity without the need for specific vitrification oriented adaptions.