Introduction to the Archaea Life's extremists. . . . Dr. Carl Woese U of Illinois DNA sequences.
Life's extremists. . .
Finding Archaea : The hot springs of Yellowstone National Park, USA, were among the first places Archaea were discovered. At left is Octopus Spring, and at right is Obsidian Pool. Each pool has slightly different mineral content, temperature, salinity, etc., so different pools may contain different communities of archaeans and other microbes. The biologists pictured above are immersing microscope slides in the boiling pool onto which some archaeans might be captured for study.
Salt-lovers : immense bloom of a halophilic ("salt-loving") archaean species at a salt works near San Quentin, Baja California Norte, Mexico. This archaean, Halobacterium, also lives in enormous numbers in salt ponds at the south end of San Francisco
Methanococcus jannischii was originally isolated from a sample taken from a "white smoker" chimney at an oceanic depth of 2,600 meters on the East Pacific Rise.
Halobacterium salinarium is an extreme halophile that grows at 4 to 5 M NaCl and does not grow below 3 M NaCl
Sulfolobus acidocaldarius (T.D. Brock)Sulfolobus is an extreme thermophile that has been found in geothermally-heated acid springs, mud pots and surface soils with temperatures from 60 to 95 degrees C, and a pH of 1 to 5
The copper-tolerant, acidophilic bacteria seen in this electron micrograph extract high concentrations of copper from sulfide minerals without being harmed
Not so inhospitable : It used to be unthinkable that life could exist at temperatures near boiling, but some archaeans thrive under these conditions. Geysers, like the one shown above, are home to such microbes and may help us understand how life existed when the Earth was young.
Archaea: isoprene cell wall
Plants: cellulosic cell wall
Fungi: chitinous cell wall
The picture is a short chain of cyanobacterial cells from the Bitter Springs Chert of Northern Australia (about 1 billion years old).
-rock made of banded domes of sediment in which are
found the most ancient forms of life: prokaryotes dating back as far as 3.5 BYO
Bacterial Way of Life: Response to Gaseous Oxygen
Bacterial Way of Life: Mode of Reproduction
Bacterial Way of Life: Number of Cells
Endotoxins vs.Exotoxins vs. Endospore
Produce antibiotics such as streptomycin
Symbiont in animals (including humans), roots of certain plants (nitrogen fixation)
Yogurt, fermented milk, sourdough bread
A major decomposer