Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Bacteria Physiology in Low Temperatures
Name: Manjiri
Status: Student
Grade:  9-12
Location: N/A
Country: United States
Date: August 2006

What happens to bacteria functioning in low temperature?

Like all chemical reactios, biochemical reactions (even those catalyzed by enzymes) slow down by a factor of 2-3 for every 10 degrees C lowering of the temperature. At a certain temperature, some enzymes in a bacterium may fold incorrectly and as a result stop catalyzing all together thus causing death of the cell.

Ron Baker, Ph.D.

Your question is very timely. In the 12-18 August issue of the journal "NEW SCIENTIST" is an article on exactly this topic, entitled "Sub-Zero Survivors". It is mind boggling. Historically, microbiologists have estimated that the "absolute zero" of metabolism of microbes was about -20C. This put a damper on the prospects of finding "life" on Mars, the moons of Jupiter etc. which never rise above about -40C. However, research has shown that a species of bacteria "Colwellia 34H" thrive at temperatures of about -50C. because the freezing of salt water excludes salt from the liquid phase, leaving liquid water for this bacterium to exist.

Another environment is the nanofilms of glassy water that exists at even lower temperatures. In this environment, the viscosity of glassy water is so high that it cannot crystallize and is available to sustain microbial life (PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES, vol.102, pg 10913). There is even evidence, although not universally accepted, that cells can survive at the boiling point of liquid nitrogen (-196 C.)!!

There are other examples of cellular life at intermediate temperatures. Of course, metabolism slows, but the fact that there is even a hint of life at these low temperatures is fascinating.

Check the website:

Vince Calder

Click here to return to the Molecular Biology Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory