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The Archaeans

The Archaeans. Deep Sea Vents. Laura Rodriguez Microbiology B235 CRN# 10582 February 19, 2007. The Dead Sea. Yellowstone. Essential Questions. 1. What are the Archaea? 2. What makes them different from bacteria and eukaryotes? 3. Where are Archaea found?

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The Archaeans

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  1. The Archaeans Deep Sea Vents Laura RodriguezMicrobiology B235CRN# 10582 February 19, 2007 The Dead Sea Yellowstone

  2. Essential Questions 1. What are the Archaea? 2. What makes them different from bacteria and eukaryotes? 3. Where are Archaea found? 4. What are some special Archaeans MethanopyrusCourtesy Karl Stetter

  3. Discovery of the Archaea • Dr. Carl Woese was studying DNA sequences to determine relationships among prokaryotes in the late 1970’s . • He found 2 distinct groups. Those prokaryotes living in extreme conditions were very different from the usual bacteria and also from eukaryotes • He came up with 3 domains: • Archaea • Bacteria • Eukaryota

  4. Archaea Groups The Archaeans have been divided into 3 groups • Euryarcheota methane producers, salt lovers • Crenarcheota extreme temperatures • Korarcheota • recently discovered, based on DNA sequences

  5. Sub groups of Archaeans • Methanogens - produce methane gas as a waste product. • Halophiles - live in salty environments. • Thermophiles - live at extremely hot temperatures. • Sychrophiles - live at unusually cold temperatures.

  6. Morphology Very small – less than 1 micron Many shapes – coccus, bacillus, triangular, square May have 1 or more flagella No internal membranes DNA in a single loop – plasmid tRNA different from all other life forms Some characteristics of tRNA more similar to eukaryotes than to bacteria Ribosomes also more like eukaryotes than bacteria RNA sequences different from bacteria and eukaryotes

  7. Archaeans are structurally similar to bacteria but chemically different • Cell Wall is not made of peptidoglycan, chitin or cellulose, but is chemically distinct (pseudomurein) • Cell Membrane also very different chemically • chirality of glycerol: Archaeans have L glycerol instead of D • ether linkage instead of an ester linkage –Archaean linkage lacks an oxygen atom and gives membrane different chemical properties • isoprenoid chains instead of fatty acid side chains • branching of side chains. This does not occur in bacteria or eukaryotes Archaeans can form transmembrane phospholipids and carbon rings. This may contribute to membrane stability at high temperatures

  8. Fossil Record • Difficult to find fossils of such small organisms. Physically would look the same as bacteria. • Need to look for molecular fossils – chemicals that are unique to the organism that do not decay or decay into predictable and known secondary chemicals • Isoprenes are such molecular fossils of archaeans. They have been found in the Isua district of Western Greenland which contains the oldest sediments known – 3.8 billion years old

  9. Archaeans as earliest life • Archaeans were on earth within 1 billion years of Earth forming. • Earth was still very hot, lots of methane and ammonia. • Toxic for life today, but just right for archaeans.

  10. Location, Location, Location Extreme environments • Deep sea hydrothermal vents • Hot springs • Hypersaline waters • Extremely alkaline or acidic environments • Digestive tracts of termites, cows and marine life • Anoxic muds of marshes • Petroleum deposits • Ocean bottom • Open ocean in plankton MethanothermusCourtesy Karl Stetter

  11. Halobacterium • One of the most studied Archaeans • Salt loving – found in salt ponds at SE end of San Francisco Bay, Dead Sea • Contains bacteriorhodopsin, light-sensitive pigment that gives Halobacterium its color • This is a simple photosynthetic pigment similar to rhoodopsin found in vertebrate retina • Found to withstand lethal doses of UV radiation, extreme dryness and eve the vacuum of space

  12. Salt flats at Lake Magadi, Kenya. The flats are red due to the proliferation of Halobacteria.

  13. Pyrolobus fumarii • Literally, “fire lobe of the chimney” • Found at the deep sea vents in “black smokers” • Increased the accepted upper temperature limit for life to 113 degrees Celsius (235.4 degrees Fahrenheit). Pyrolobus fumarii-Zellen, EM-Aufnahme - Image courtesy H. Huber, M. Hohn, R. Rachel & K.O. Stetter, Univ. Regensburg, Germany

  14. Pyrococcus furiosis • Live near deep sea vents • Produce fuel, hydrogen gas • Produces an extra-stable enzyme that isn’t denatured as it goes through many cycles in the process of polymerase chain reaction,PCR. This is the method that is used for gene sequencing and DNA fingerprinting. Courtesy of K.O. Stetter and R. Rachel, University of Regensburg.

  15. Archaeoglobus fulgidus • Anaerobes • Hyperthermophilic • Marine sulphate reducers • Found in hydrothermal environments • Contributes to subsurface oil-well 'souring' by iron sulphide, • Causes corrosion of iron and steel in oil-and gas-processing systems. • Courtesy Karl Stetter

  16. Credits • "Archaea and other extremists." Microbe World. 2006. American Society for Microbiology . 14 Feb 2007 <http://www.microbeworld.org/microbes/archaea/>. • "Archaeoglobus fulgidus ." TIGR. 2007. The Institute for Genomic Research. 18 Feb 2007 <http://www.tigr.org/tdb/CMR/gaf/htmls/Background.html>. • Barry, Patrick l.. "Secrets of a salty survivor." Science @ NASA . September 9, 2004 . NASA. 12 Feb 2007 <http://science.nasa.gov/headlines/y2004/10sep_radmicrobe.htm>. • Beal, Heather. "Microbial Life in Extremely Hot Environments." Microbial Life Education Resources. November 30. 2006 . SERC. 14 Feb 2007 <http://serc.carleton.edu/microbelife/extreme/extremeheat/index.html>. • Blöchl, Elisabeth, Reinhard Rachel, Siegfried Burggraf, Doris Hafenbradl, Holger W. Jannasch, and Karl O. Stetter . "Pyrolobus fumarii, gen. and sp. nov., represents a novel group of archaea, extending the upper temperature limit for life to 113°C ." Extremophiles Journal Vol 1 issue 1February 19, 2004 14-21. February 18, 2007 <http://www.springerlink.com/content/g5tdkx307y56g0n0/>. • "Diversa Completes of Sequencing of Pyrolobus fumarii Genome - the World's Highest Temperature Organism ." SpaceRef Interactive Inc. September 25,2001 . Diversa. 18 Feb 2007 <http://www.spaceref.com/news/viewpr.html?pid=6101>. • "First salt-loving bug sequenced ." BBC News 2 October, 2000 February 10, 2007 <http://news.bbc.co.uk/2/hi/sci/tech/953356.stm>. • Tortora, Gerard, Berdell Funke, and Christine Case. Microbiology:An Introduction. 9th. San Francisco: Pearson Education, Inc, 2007. • Waggoner, Ben, and Brian Speer. ", Introduction to the Archaea: Life's extremists ." University of California Museum of Paleontology. 1994-2007. University of California Museum of Paleontology. 10 Feb 2007 <, http://www.ucmp.berkeley.edu/archaea/archaea.html>. • Zaun, Harald. "Von irdischen und außerirdischen Überlebenskünstlern." Mikrobiologe und Astrobiologie . August 23,2003. Heise Zeitschriften Verlag . 18 Feb 2007 <http://www.heise.de/tp/r4/artikel/15/15412/1.html>.

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