They are theorized to be a possible analogues for modeling extremophiles that might live in the salty subsurface water ocean of Jupiter's Europa and similar moons.
To survive the high salinities, halophiles employ two differing strategies to prevent desiccation through osmotic movement of water out of their cytoplasm.
[3] The most common compatible solutes are neutral or zwitterionic, and include amino acids, sugars, polyols, betaines, and ectoines, as well as derivatives of some of these compounds.
The presence of this adaptation in three distinct evolutionary lineages suggests convergent evolution of this strategy, it being unlikely to be an ancient characteristic retained in only scattered groups or passed on through massive lateral gene transfer.
These are the primary inhabitants of salt lakes, inland seas, and evaporating ponds of seawater, such as the deep salterns, where they tint the water column and sediments bright colors.
Their cellular machinery is adapted to high salt concentrations by having charged amino acids on their surfaces, allowing the retention of water molecules around these components.
[2][4] The Haloarchaea, and particularly the family Halobacteriaceae, are members of the domain Archaea, and comprise the majority of the prokaryotic population in hypersaline environments.
[8] A comparatively wide range of taxa has been isolated from saltern crystalliser ponds, including members of these genera: Haloferax, Halogeometricum, Halococcus, Haloterrigena, Halorubrum, Haloarcula, and Halobacterium.
Only recently has it become possible to determine the identities and relative abundances of organisms in natural populations, typically using PCR-based strategies that target 16S small subunit ribosomal ribonucleic acid (16S rRNA) genes.
The comparative genomic and proteomic analysis showed distinct molecular signatures exist for the environmental adaptation of halophiles.
[11] In one study, the net charges (at pH 7.4) of the ribosomal proteins (r-proteins) that comprise the S10-spc cluster were observed to have an inverse relationship with the halophilicity/halotolerance levels in both bacteria and archaea.
Wallemia ichthyophaga is a basidiomycetous fungus, which requires at least 1.5 M sodium chloride for in vitro growth, and it thrives even in media saturated with salt.