Introduction to the Archaea Life's extremists. . .

3. Introduction to the Archaea Life's extremists. . . • Dr. Carl Woese • U of Illinois • DNA sequences

5. 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.

6. 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

7. Different groups of Archaea: • Halophiles: extreme salt concentration • Thermophiles: extremely high temperature • Psychrophiles: extremely cold temperature • Alkalidophiles/Alkaliphiles: extreme basic condition • Acidophiles: extreme acidic condition • Methanogens: under the mud • Planktonic: open sea with planktons

8. 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. METHANOGEN Halobacterium salinarium is an extreme halophile that grows at 4 to 5 M NaCl and does not grow below 3 M NaCl HALOPHILE

9. 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 THERMOPHILE The copper-tolerant, acidophilic bacteria seen in this electron micrograph extract high concentrations of copper from sulfide minerals without being harmed ACIDOPHILE

10. 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.

11. Bacteria: peptidoglycan cell wall Archaea: isoprene cell wall Plants: cellulosic cell wall Fungi: chitinous cell wall

13. Bacteria: The Modern Microbes

14. Bacteria: Fossil Record The picture is a short chain of cyanobacterial cells from the Bitter Springs Chert of Northern Australia (about 1 billion years old). Palaeolyngbya sp. • the Cyanobacteria or "blue-green algae“ (previous classification system) have left a fossil record that extends far back into the Precambrian (Stromatolites) • the oldest cyanobacteria-like fossils known are nearly 3.5 billion years old, among the oldest fossils currently known

15. STROMATOLITES -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 LAYERS

16. Aerobe vs. Anaerobe • 2. Facultative anaerobe • 3. Obligate aerobe and anaerobe Bacterial Way of Life: Response to Gaseous Oxygen Bacterial Way of Life: Mode of Reproduction • Asexual vs. Sexual • Asexual- Binary fission vs. Budding Bacterial Way of Life: Number of Cells • Unicellular vs. Multicellular

17. Bacterial Way of Life: Ways of Obtaining Energy • Autotrophic vs. Heterotrophic • a. Chemoautotroph vs. Photoautotroph • b. Chemoheterotroph vs. Photoheterotroph

18. Bacterial Way of Life: Response to Gram Staining

19. Bacterial Way of Life: Released Toxins & Adaptation Endotoxins vs.Exotoxins vs. Endospore

21. Bacterial Way of Life: 3 Mechanisms of Genetic Recombination Conjugation

23. Transduction Transduction

25. Benefits from Prokaryotes Produce antibiotics such as streptomycin Symbiont in animals (including humans), roots of certain plants (nitrogen fixation) Yogurt, fermented milk, sourdough bread A major decomposer