•Extreme halophiles(salt lovers) are obligate aerobes. They inhabit in the hypersalineenvironments (≥1.5M or about 9% NaCl) such as salt lakes, salted food (salted fish meats).
•Haloarchaeastain gram-negatively, reproduce by binary fission and do not form resting stages or spores.
•Osmotic balance: pump K+ into the cell so that the concentration of K+ inside the cell is greater than the concentration of Na+ outside the cell.
•Light-mediated ATP synthesis in haloarchaeaoccurs without chlorophyll pigments so it is not photosynthesis.
•Bacteriodopsin: a caroteinoid-like protein which is inserted into the cytoplasmic membrane
•Bacteriodopsincan absorb light energy and pump a proton across the membrane.