Microbial community of the deep-sea brine Lake Kryos seawater-brine interface is active below the chaotropicity limit of life as revealed by recovery of mRNA.
Environ Microbiol
; 17(2): 364-82, 2015 Feb.
Article
en En
| MEDLINE
| ID: mdl-25622758
ABSTRACT
Within the complex of deep, hypersaline anoxic lakes (DHALs) of the Mediterranean Ridge, we identified a new, unexplored DHAL and named it 'Lake Kryos' after a nearby depression. This lake is filled with magnesium chloride (MgCl2 )-rich, athalassohaline brine (salinity > 470 practical salinity units), presumably formed by the dissolution of Messinian bischofite. Compared with the DHALâ
Discovery, it contains elevated concentrations of kosmotropic sodium and sulfate ions, which are capable of reducing the net chaotropicily of MgCl2 -rich solutions. The brine of Lake Kryos may therefore be biologically permissive at MgCl2 concentrations previously considered incompatible with life. We characterized the microbiology of the seawater-Kryos brine interface and managed to recover mRNA from the 2.27-3.03 M MgCl2 layer (equivalent to 0.747-0.631 water activity), thereby expanding the established chaotropicity window-for-life. The primary bacterial taxa present there were Kebrit Deep Bacteria 1 candidate division and DHAL-specific group of organisms, distantly related to Desulfohalobium. Two euryarchaeal candidate divisions, Mediterranean Sea Brine Lakes group 1 and halophilic cluster 1, accounted for > 85% of the rRNA-containing archaeal clones derived from the 2.27-3.03 M MgCl2 layer, but were minority community-members in the overlying interface-layers. These findings shed light on the plausibility of life in highly chaotropic environments, geochemical windows for microbial extremophiles, and have implications for habitability elsewhere in the Solar System.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Agua de Mar
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Bacterias
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Lagos
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Archaea
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Consorcios Microbianos
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Environ Microbiol
Asunto de la revista:
MICROBIOLOGIA
/
SAUDE AMBIENTAL
Año:
2015
Tipo del documento:
Article
País de afiliación:
Italia