Part of what interests me about the possibility of bacterial life outside of earth is the amazing versatility of microorganisms in Earth's harshest environments. My personal favorite are the bacterial colonies which grow on nuclear fuel rods. Pretty much anywhere that has been carefully looked at has a detectable microbial presence.
In that light, it's not surprising that deep, anoxic, hypersaline basins on the Mediterannean sea floor are also teeming with life. These pools form in isolated spots on the seafloor where tectonic activity exposes a rock layer rich in salts. The salts dissolve, generating a shallow depression and imparting high density to the dissolving water. Thus it is stagnant, anoxic, and very, very salty. What is a surprise is that eukaryotic organisms such as protists and fungi seem to also have found a home in this area. It will be interesting to find out what energy source is ultimately powering this community.