Low temperature is a predominant environmental characteristic
of interstellar space, asteroids, meteors and, of course,
our solar system, including most of the planets and their
satellites. An understanding of the impacts that low temperature
have on the responses and evolution of biological organisms
is, therefore, integral to our knowledge of Astrobiology.
Toward this end, we are exploring multiple aspects of microbial
adaptation to low temperature. One major line of investigation—Genomic
and Proteomic Analysis of Permafrost Bacteria—is to conduct
genomic and proteomic analyses of bacteria that have been
isolated from the Arctic and Antarctic permafrost.
Our basic objectives include identifying genes and proteins
that enable permafrost bacteria to inhabit subfreezing environments
and determining how genome expression in the permafrost bacteria
is affected by low temperature and other environmental conditions
associated with the permafrost and those that "hitchhiker"
bacteria might encounter during travel through space on natural
objects or spacecraft.
In a second major line of investigation—Bacterial Adaptation
to Low Temperature—we are directly examining, through "test-tube
evolution" experiments, how bacteria genetically adapt
to low temperatures. The fundamental objective here is to
better understand how an organism, with a given complement
of genes, can cross niche barriers that are defined by decreasing
Finally, in a "Field Truth" investigation—Indigenous
Bacteria of Arctic and Antarctic Permafrost—we are exploring
the microbial ecology of the permafrost environment and the
physiological state of the resident microbial community. This
is being accomplished by determining the phylogenetic diversity
of the bacterial permafrost population and the metabolic activities
present in permafrost soils.
Project team members at our annual project meeting
standing (l-r): David Lubman, Michael Thomashow, Lekan Latinwo, David
Gilichinsky, James Tiedje, Sean Sleight, Monica Ponder, Uwe
seated (l-r): Hector Ayala-del-Rio, Lycely del C. Sepulveda,
Debora Rodrigues, Peter Bergholz, Sarah Gilmour.