Salinibacter ruber is an extremely halophilic red bacterium, first found in Spain in 2002.

Salinibacter ruber
Scientific classification
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S. ruber
Binomial name
Salinibacter ruber
Antón et al., 2002

Habitat

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Salinibacter ruber 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 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]

Taxonomy

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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 extremely halophilic. The type strain is strain M31T(= DSM 13855T = CECT 5946T).

Characteristics

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In a 2015 study conducted by researchers led by molecular biologist Ken McGrath at Lake Hillier, Western Australia, showed that, while the algae Dunaliella salina, formerly thought to create the color in this pink lake, was present in only tiny quantities (0.1% of DNA sampled), while S. ruber formed 20[2] to 33%[4][5][3][a] of the DNA recovered from the lake.[2]

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]

Footnotes

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  1. ^ Conflicting reports of percentage.

References

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  1. ^ a b c Antón J; Oren A; Benlloch S; Rodríguez-Valera F; Amann R; Rosselló-Mora R (March 2002). "Salinibacter ruber gen. nov., sp. nov., a novel, extremely halophilic member of the Bacteria from saltern crystallizer ponds". International Journal of Systematic and Evolutionary Microbiology. 52 (Pt 2): 485–91. doi:10.1099/00207713-52-2-485. hdl:21.11116/0000-0001-D329-3. PMID 11931160. Retrieved 2013-07-24.
  2. ^ a b c Salleh, Anna (4 January 2022). "Why Australia has so many pink lakes and why some of them are losing their colour". ABC News. ABC Science. Australian Broadcasting Corporation. Retrieved 21 January 2022.
  3. ^ a b c Cassella, Carly (13 December 2016). "How an Australian lake turned bubble-gum pink". Australian Geographic. Retrieved 22 January 2022.
  4. ^ "Here's the Real Reason Why Australia Has Bubblegum Pink Lakes". Discovery. 24 December 2019. Retrieved 22 January 2022.
  5. ^ "Why is Pink Lake on Middle Island, off the coast of Esperance, pink?". Australia's Golden Outback. Includes extract from Australian Geographic article. 18 January 2021. Retrieved 22 January 2022.{{cite web}}: CS1 maint: others (link)

Further reading

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