Salinibacter: an extremely halophilic bacterium with archaeal properties

Abstract

The existence of large number of a member of the Bacteroidetes in NaCl-saturated brines in saltern crystallizer ponds was first documented in 1999 based on fluorescence in situ hybridization studies. Isolation of the organism and its description as Salinibacter ruber followed soon. It is a rod-shaped, red-orange pigmented, extreme halophile that grows optimally at 20-30% salt. The genus is distributed worldwide in hypersaline environments. Today, the genus Salinibacter includes three species, and a somewhat less halophilic relative, Salisaeta longa, has also been documented. Although belonging to the Bacteria, Salinibacter shares many features with the Archaea of the family Halobacteriaceae that live in the same habitat. Both groups use KCl for osmotic adjustment of their cytoplasm, both mainly possess salt-requiring enzymes with a large excess of acidic amino acids, and both contain different retinal pigments: light-driven proton pumps, chloride pumps, and light sensors. Salinibacter produces an unusual carotenoid, salinixanthin that forms a light antenna and transfers energy to the retinal group of xanthorhodopsin, a light-driven proton pump. Other unusual features of Salinibacter and Salisaeta include the presence of novel sulfonolipids (halocapnine derivatives). Salinibacter has become an excellent model for metagenomic, biogeographic, ecological, and evolutionary studies.

Interactions between Closely Related Bacterial Strains Are Revealed by Deep Transcriptome Sequencing

“…For instance, significant expression levels were detected for complete Embden-Meyerhof glycolysis, including fructose-1,6-bisphosphate aldolase, whose activity was not detected previously (33). Alternative glucose degradation by the Entner-Doudoroff pathway presented decreasing expres- sion levels from the first reaction, supporting the lack of activity of 2-keto-3-deoxy-6-phosphogluconate aldolase reported previously (34).…”

Prokaryotic Community Structure Driven by Salinity and Ionic Concentrations in Plateau Lakes of the Tibetan Plateau

“…S1 in the supplemental material). Perhaps this was because of their high degree of adaptability to hypersaline waters (1,70). Other phyla abundant in six of the lakes (with Lake Gasikule being the exception) were Proteobacteria, Actinobacteria, Verrucomicrobia, and Planctomycetes.…”

“…They are distributed in hypersaline waters worldwide and are frequently dominant (69,70). Unclassified class At12OctB3 within the Bacteroidetes, which was detected for the first time in a hyper- saline lake (1), comprised 3.7 to 8.3% of the sequences in each sequencing library for Lake Gasikule.…”

Isolation and Characterization of Haloarchaeal Strain from Puthalam Salt Pan located in the Southern Peninsular Coast of India

“…In the present inquest red coloured colonies were used for further analysis. The study based on extremely halophilic Archaea are capable of producing red pigments known as carotenoids which gives red, yellow and orange colour to the organism and also to compact the high salt and intense UV radiation [15]. It was shown that these colored pigments have strong antioxidant, immune boosting activities and protecting premature ageing [16].…”