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The drying-out of the Aral Sea Basin is considered a catastrophic ecological problem of Central Asia and caused massive salinization and desertification of lands. Many halotolerant and halophilic bacteria were isolated and detected in hypersaline soils of arid regions, but their taxonomic description has not yet been completed, and their distribution and ecology have not yet been fully studied in detail (Oren, 2011). Our studies were focused on examining the biodiversity and ecology of the rhizosphere microbiome of Salicornia, a halophytic plant widely distributed in this region, and host to many representatives of halophilic microorganisms, to characterize the role of the halophilic microbiome in the growth of the host plant. To achieve this goal we carried out Illumina sequencing of the V4 hypervariable region of the 16S rRNA genes amplified from total DNA of selected soils. The experiments were performed according to standard methods. The results show that the major taxonomic groups of halophilic bacteria belong to the genera Marinococcus (2%), Alcalibacterium (1%), and Halomonas (3%), to the Actinobacteria (2%), and to the families Alteromonadales (2%), Nitriliruptoraceae (2%), and Desulfobulbaceae (1%). Representatives of the archaeal domain included several genera: Natronococcus (4%), Haloterrigena (3%), Halovivax (2%), Halorubrum (2%), and Halomicrobium (2%). The research of the diversity and ecology of halophilic bacteria and archaea in the Salicornia rhizosphere provides a theoretical concept and knowledge, while also offering future prospects to evaluate and develop potential biotechnological applications. [ABSTRACT FROM AUTHOR]

At present, the surface of Mars is affected by a set of factors that can prevent the survival of Earth-like life. However, the modern concept of the evolution of the planet assumes the existence more favorable for life climate in the past. If in the past on Mars had formed a biosphere, similar to the one that originated in the early Earth, it is supposed that it is preserved till now in anabiotic state in the bowels of the planet, like microbial communities inhabiting the ancient permafrost of Arctic and Antarctic. In the conditions of modern Martian regolith, this relic life seems to be deprived of the possibility of damage reparation (or these processes occur on a geological time scale), and ionizing radiation should be considered the main factor inhibiting such anabiotic life. In the present study, we studied soil samples, selected in two different extreme habitats of the Earth: ancient permafrost from the Dry Valleys of Antarctica and Xerosol soil from the mountain desert in Morocco, gamma-irradiated with 40 kGy dose at low pressure (1 Torr) and low temperature (-50 °C). Microbial communities inhabiting these samples showed in situ high resistance to the applied effects, retained high number of viable cells, metabolic activity, and high biodiversity. Based on the results, it is assumed that the putative biosphere could be preserved in the dormant state for at least 500 thousand years and 8 million years in the surface layer of Mars regolith and at 5 m depth, respectively, at the current level of ionizing radiation intensity., Competing Interests: Conflict of interest: The authors declare no conflicts of interest in this article.