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
