12 Microbial Life in Brines, Evaporites and Saline Sediments: The Search for Life on Mars

Abstract

When water on a planet begins to evaporate the dissolved minerals become more concentrated, form a brine, eventually precipitating out of solution and forming evaporite deposits. The brines and evaporites form a highly saline environment that is hostile to most life forms, but provides an ideal habitat for organisms that are osmophilic, or halophilic. Halophiles are salt “loving” organisms that inhabit environments with salt concentrations ranging from 15 % to saturation. On Earth, representatives of halophiles occur in all three domains of life, the Archaea, Bacteria and Eukarya.