Part 4: Diversity of Archaea Flashcards
How many phyla are Archaea split into?
5
Key genus of Haloarchaea
Halobacterium
Environment of Halobacterium
Minimum 1.5 M (~9%) NaCl for growth
Halobacterium are found in?
Solar salt evaporation ponds and salt lakes where salt concentrations approaches saturation - highly alkaline hypersaline environments
How do halophiles maintain osmotic balance?
Accumulation or synthesis of compatible solutes
Halobacterium pump large amounts of what into the cell?
K+ into the cell - intracellular K+ concentration exceeds extracellular Na+ concentration and positive water balance is maintained
What is a unique feature found only in some haloarchaea?
Light-driven synthesis of ATP using bacteriohodopsin
Bacteriorhodopsin
Cytoplasmic membrane proteins that can absorb light energy and pump proteins across the membrane to make ATP
Cannot fix CO2
= photoheterotrophs
Key genera of Methanogenic Archaea
Methanobacterium, Methanosarcina
Methanogens are the only microbes capable of?
Significant methane production
What do methanogens produce?
The bulk of CH4 in the atmosphere (green house gas)
Methanogens are strict
Anaerobes
Where are methanogens found in?
Diverse anaerobic environment - cow’s gut, sewage sludge
Methanobacteriales cell wall
Composed of pseudomurein similar in structure to peptidoglycan
Methanogen cell wall type
S-layer made of protein or glycoprotein
Obligate anaerobes use what substrates
H2+CO2, formate, acetate, methanol
Methanobacterium use what substrates
H2+CO2 but not methanol or acetate
Methanosarcine use what substrates
Acetate and methanol but only some can use H2+CO2
How do methanogens use glucose?
It can be converted to methane but only in a cooperative reaction between them and other anaerobic bacteria
Key genus of Thaumarchaeota
Nitrosopumilus
How does Nitrosopumilus grow?
Chemolithotrophically by aerobically oxidizing ammonia
Nitrosopumilus carbon source
CO2
Nitrosopumilus can grow
At very low levels of ammonia
What do indigenous Nitrosopumilus do?
Ammonia oxidation in open ocean water
What can Nitrosopumilus do for the soil?
Nitrify it
Example of Nanoarchaeota
Nanoarchaeum equitans
Size of Nanoarchaeum equitans
~0.4 micrometers
Nanoarchaeum equitans forms a symbiotic relationship with
Crenarchaeote Ignicoccus
Genome of Nanoarchaeum equitans
Smallest genome known
Nanoarchaeum lack
Genes for all but core molecular processes
Nanoarchaeum rely on the host for
Most of its cellular needs
Korarchaeum cryptofilum metabolism
Obligately anaerobic chemoorganotrophic
Korarchaeum cryptofilum environment
Hyperthermophile
Korarchaeum cryptofilum cells
Long, thin filaments that lack many core genes
Korarchaeum cryptofilum rely on
Other members of hot spring community
Most Crenarchaeota are
Hyperthermophiles but some lives in extremely cold environments
Metabolism of Crenarchaeota
Chemoorganotrophs or chemolithotrophs
Crenarchaeota respiration
Aerobically or anaerobic
Crenarchaeota accepts what electons
NO3-, S0, Fe3+
Crenarchaeota donates what electrons
H2
Example of Crenarchaeota
Sulfolobus
Sulfolobus lives in
Sulfur-rich acidic hot spring (pH 2)
Sulfolobus metabolism and respiration
Aerobic chemolithotrophs
Sulfolobus oxidize
Reduce sulfur or iron
Crenarchaeota contain several representatives which have an optimum growth temperature
Above 100C
Geogemma barossii can grow up to
121C
