BIOM-360 Lecture Notes - Lecture 11: Thaumarchaeota, Nanoarchaeota, Proteobacteria
2 May 2018
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Exam will be 50 multiple choice questions, next Monday.
Archaeal Diversity
Archaea
Share features with bacteria and eukarya.
Once thought to be extremophiles, actually widespread amongst habitats.
DNA replication, transcription, and translation are similar to eukaryotes.
Seem to be closer to eukaryotes than bacteria.
Unique features: tRNA structure and methane production.
Very diverse, different morphologies and metabolism.
Unique cell wall with ether links and no peptidoglycan. (Bacterial cell walls have ester links.)
Many are extremophiles, but also colonize non-extreme environments.
Work in Progress
Environmental sequences: more organisms discovered every day.
Archaea seem to be less diverse than bacteria.
“-chaeota” indicates archaeal phyla.
Euryarchaeota
Diverse metabolism (include methanogens, extreme halophiles, sulfate reducers, extreme therm.)
Methanogens generate methane from CO2 and hydrogen
Methanotrophs that consume methane
Extreme halophiles = absolutely dependent on high [NaCl] or cell wall disintegrates.
Crenarchaeota
Mostly thermophiles in unusual environments (hot springs)
Thermophilic and many are sulfur dependent.
Found in geothermal water and submarine volcanoes.
Can survive autoclaving.
Thaumarchaeota
(Nanoarchaeota, Korarchaeota)
Non-extremophiles.
Abundant in soils, oceans, and freshwater.
Nitrification → require very low amounts of ammonia.
*Important role in the nitrogen cycle.
Thaumarchaeota = lipid specific to thaumarchaeota.
Bacterial Diversity
Bacteria
Over 80 bacterial phyla.
Most bacterial diversity included in: Firmicutes, Actinobacteria, Proteobacteria, Bacteriodetes.
Proteobacteria
All are gram-negative → Pink stain
E. coli is an example.
Document Summary
Exam will be 50 multiple choice questions, next monday. Once thought to be extremophiles, actually widespread amongst habitats. Dna replication, transcription, and translation are similar to eukaryotes. Seem to be closer to eukaryotes than bacteria. Unique cell wall with ether links and no peptidoglycan. (bacterial cell walls have ester links. ) Many are extremophiles, but also colonize non-extreme environments. Archaea seem to be less diverse than bacteria. Diverse metabolism ( include methanogens , extreme halophiles, sulfate reducers, extreme therm. ) Extreme halophiles = absolutely dependent on high [nacl] or cell wall disintegrates. Nitrification require very low amounts of ammonia. Most bacterial diversity included in: firmicutes, actinobacteria, proteobacteria, bacteriodetes. All are gram-negative pink stain: coli is an example. Filamentous and gliding bacteria that can be very big. Dormant stress that can resist environmental stress and persist for a long time. Bacillus subtillis: gram positive model for bacterial study: coli is to gram negative as bacillus subtillis is to gram positive.
