Salinibacter ruber

Salinibacter ruber is an extremely halophilic red bacterium that was found in saltern crystallizer ponds in Alicante and Mallorca, Spain in 2002 by Antón et al.. This environment has very high salt concentrations, and Salinibacter ruber itself cannot grow at below 15% salt concentration, with an ideal concentration between 20-30%. Salinibacter ruber survives in this harsh environment because of its adaptations in order to cope with the high salt concentrations. These adaptations are: modifying the sequences of its proteins, recruiting proteins from different sources with different functions, as well as lateral gene transfer from other halophilic organisms.

This bacterium is very interesting because of its extremophile tendencies as a bacterium, where this is common mostly in the domain Archaea. Bacteria do not, in general, play a large role in microbial communities of hypersaline brines at or approaching NaCl saturation. However, with the discovery of S. ruber, this belief was weakened. It was found that S. ruber made up from 5% to 25% of the total prokaryotic community of the Spanish saltern ponds.

Salinibacter ruber is most closely related to the genus Rhodothermus which is a thermophilic, slightly halophilic bacterium. Though genetically it is considered to be closest to the Rhodothermus genus, it is most comparable to the family Halobacteriaceae, because of similarity in protein structure. It is red-pigmented, motile, rod-shaped, and extremely halophilic. The type strain is strain M31^T(= DSM 13855^T = CECT 5946^T).