Probiotic Activity of a Bacterial Strain Isolated from Ancient Permafrost Against Salmonella Infection in Mice.

Bacillus cereus strain F, collected from relict permafrost located in Siberia, was analyzed for probiotic activity in the mouse Salmonella enterica model. Viable bacterial cells were found in frozen soils taken at Mammoth Mountain in Yakutia from a depth below the level of seasonal thawing. Geological data indicated the absence of a thawing within millions of years of deposited soils, which helped to ensure the ancient origin of our sample. According to DNA analysis, bacterial cells collected from the relict permafrost appeared to be B. cereus strain F. The morphology of these bacteria was analyzed using atomic force microscopy. B. cereus strain F was assessed as a nonpathogenic bacterium by evaluation of its pathogenicity. A S. enterica model is described in mice after per oral inoculation and serves as a model for the human carrier state. Using this model, probiotic activity by the bacterial strain isolated from the ancient permafrost has been shown against Salmonella infection in mice.

[Effects of relic microorganism B. sp. on development, gaseous exchange, spontaneous motor activity, stress resistance and survival of Drosophila melanogaster].

The effect of relic microorganism B. sp., living in severe environment of Siberian permafrost during thousands and millions of years, on development and stress resistance of Drosophila melanogaster has been studied. In manipulating with such objects with practically "eternal life span", molecular carriers of the unprecedented longevity potential and possibilities of their transmission to other biological objects should primarily be addressed. Here we discuss for the first time the influence of B. sp. application on development, survival, stress resistance and the gross physiological predictors of aging rate in D. melanogaster. To establish optimal and toxic doses, wide range of B. sp. concentrations were tested (1-500 million cells of B. sp. per 1 ml of the flies feeding medium). Surprisingly, no toxic effects of B. sp. could be registered even on such a "sensitive" model as the developing larvae. In fact, the rate of development, survival and body mass gradually increased with elevation of B. sp. concentration. The gain of higher body mass within shorter periods of development could indicate enhanced anabolic and/ or declined catabolic effects of B. sp. Higher motor activity and gaseous exchange rates were observed in imagoes developed on the mediums with B. sp. application. Survival of these flies at the heat shock (30 min at 38 degrees C) and ultraviolet irradiation (60 min, 50W UV lamp) was increased, indicating elevated stress resistance, apparently due to stimulation of DNA-repair and chaperone-mediated protection of macromolecules. Further research is clearly warranted to identify more efficient anti-stress and antiaging preparations and schemes of B. sp. application on models of laboratory mammals and human cell cultures.

[Relict microorganisms of cryolithozone as possible objects of gerontology].

Permafrost is widely distributed in the Northern Hemisphere, and its age reaches hundreds of thousands and millions of years. Permafrost contains alive microorganisms which are not frozen due to relatively high temperature of the environment (-2...-8 degrees C), but the microorganisms are immobilized and therefore aged probably similar to the age of permafrost. Longevity of the relict microbial cells is related obviously to their mechanism of protection against heat, radiation, free radicals and other damaging agents. A strain of Bacillus sp. was isolated from permafrost aged of about 3 million years, 16S rDNA sequence was identified and preliminary testing of bacterial culture on Drosophila melanogaster and mice was made. Immune stimulation and improvement of physical condition were observed, and that, together with the age of the microbial cells, presents the relict microorganisms as objects of gerontology.