A team of researchers funded by NASA’s Astrobiology Institute are applying genomics and proteomics to understand how “hitchhiker” microbes could withstand long trips on meteorites through the frigid depths of space.
The project will focus on bacteria found in permanently frozen Arctic and Antarctic soils. These indigenous microbes not only resist cold, desiccation, and starvation in the nutrient-poor permafrost environment, but they manage to stave off the effects of aging, says Jim Tiedje, director of the Center for Microbial Ecology at Michigan State University. In subzero temperatures everything slows down, so the micro-organisms cannot quickly proliferate. Instead, they maintain their DNA, cell membranes, ribosomes, and other structures, perhaps for thousands of years.
The team will use microarray gene expression analysis to focus on the roles of specific genes in coping with the cold, and HPLC separation and MALDI-TOF mass spectrometry to determine protein structure and function relationships. Collaborators at the Department of Energy’s Joint Genome Institute will sequence the bacterial genomes.
One question to be answered is whether these microbes have unique “freezing tolerance” genes and proteins, or whether their hardiness comes from specialized alleles of common bacterial genes. The bacteria are phylogenetically distant from those found in the soils of warmer regions, and are most closely related to those found in other extremely cold environments, such as Arctic sea ice.
— Sherri Chasin Calvo