Domain Archea

Question 1

Archeal traits

Answer 1

absence of peptidoglycan (methanogens have pseudo peptidoglycan)
branched chains of lipids with either (R-O-R) not ester (R-COO-R) linkages
methanogenesis only found in archaea

Question 2

Phylogeny of archaea
What are the two main types of Phyla

Answer 2

• Crenarchaeota
  – hyperthermophiles, acidophiles
  – e.g. Sulfolobus
  – <70-80oC, pH 1-3
  – oxidize H2S to sulfuric acid
• Euryarchaeota
  – greater range of metabolism
  – halophiles, high salt, may have carotenoidpigments
  – alkalinophiles, pH<11.5– methanogens

Question 3

Other Archaean phyla

Answer 3

• Extremophiles – hyperthermophiles, barophiles
• Korarchaeota- known from DNA analysis
• Nanoarcheota- very small size (“nano”)