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.[1] It is red-pigmented, motile, rod-shaped, and extremelyhalophilic. The type strain is strain M31T(= DSM 13855T = CECT 5946T).
Habitat
Salinibacter ruber was found in salterncrystallizer 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 and 30%[1] It has also been found in pink lakes in Australia.[2][3] (200-300 grams of salt per litre, the average concentration in the ocean being around 35 g/L).
This bacterium is notable for its halophilic lifestyle, a trait exhibited primarily by members of Archaea. In general, bacteria do not 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 challenged. It was found that S. ruber made up from 5% to 25% of the total prokaryotic community of the Spanish saltern ponds.[1]
Salinibacter ruber produces a pigment called bacterioruberin, which helps it to trap and use light for energy in the photosynthesis process. While the pigments in algae are contained within the chloroplasts, bacterioruberin is spread across the whole cell of the bacterium. This makes it more likely that the colour of the lake is that of S. ruber.[3]
