Polar Bugs in Your Backyard
Extreme Life Briefing
Hottest: 235 F (113 C) Pyrolobus fumarii (Volcano Island, Italy)
Coldest: 5 F (-15 C) Cryptoendoliths ( Antarctica)
Highest Radiation: (5 MRad, or 5000x what kills humans) Deinococcus radiodurans
Deepest: 3.2 km underground
Acid: pH 0.0 (most life is at least factor of 100,000 less acidic) pH 5-8
Basic: pH ~13(most life is at least factor of 1000 less basic) pH 5-8
Longest in space: 6 years Bacillus subtilis (NASA satellite)
To study the bacteria which survive in extreme cold, scientists no longer have to go to extreme environments, such as Antarctic lakes and glaciers. Bacteria previously isolated from polar climates, and have properties which allow them to survive in extreme cold, have been isolated from soil in temperate environments.
Professor Virginia Walker and her colleagues at Queen's University, Canada, have developed a technique to isolate bacteria which have properties to interact with, and modify, ice. This technique involved the formation of an 'ice finger' (or lolly) to select for bacteria which will adsorb to ice. These bacteria were then cultured and identified using their DNA.
The bacteria can modify ice and water in a number of ways. One of the species identified, Chryseobacterium sp., demonstrated Ice Recrystallisation Inhibition (IRI), a property that can be exploited in the production of ice-cream to prevent it from recrystallising and becoming 'crunchy'.
Other species isolated in this study promote the formation of ice crystals at temperatures close to melting, a property which is useful in the production of artificial snow.
Pseudomonas borealis is one species which is not only ice-forming, it is also thought to be tolerant to cold and could therefore have advantages for snow-making in artificial environments such as ski centres and in waste-water purification.
"Selecting for rare microbes that seem to stick to ice has been fun, but now the real work begins to find out what genes are responsible for this attraction" Said Professor Walker.
These findings will decrease the costs involved in the further study of such bacteria and their properties, as scientists will no longer need expeditions to the poles in order to isolate the bugs; they can find them in their own backyards.
Related Web Pages
Microbes, Microbes Everywhere
Expect Life to be Cold
Deliquescence in the Atacama
Did Hades Freeze Over?
The Unboilable Bug