Fossil bacteria are evolutionarily valuable forms of life. In permafrost conditions for a very long time, bacteria can develop a unique repair mechanisms of structural and functional defects. In the experiment on mice of BALB/c it was revealed the presence of high reparative capacity in fossil bacteria strain MG8 Bacillus sp., isolated from samples of relict permafrost, and their metabolic products – metabolites that can be delegated to other living systems. Ability to regulate reparative processes in macroorganism shows in MG8 in the doses less than 20×1103 microbial cells and topically on the wound surface. The “thermal" metabolites, produced by culturing the bacteria at 37°C, are leaders modulation of repair processes in healing skin blemishes. Local application on the wound ointment with "heat" metabolites allows to accelerate by 30% the process of reparation relative to placebo, by 20% – relative to the medicinal product "Solcoseryl" and by 10% – faster than under the influence of bacteria. Dynamics of morphogenetic processes in the healing of skin defect under MG8 bacteria effect and their metabolites is correlated with the dynamics of immune system activity. The sequence of changes in the activity of various components of the immune system (cellular factors inherent immunoresistance – cell immunity humoral immunity) corresponds to the stage of development of the repair process (damage – inflammation – recovery). Mechanisms of regulation of repair processes in the immune system consistent with the general laws regulating the inflammatory process and changes in waves: the predominant increase in the activity of pro-inflammatory mechanisms replaced predominant anti-inflammatory mechanisms of increased activity of the immune system. Using strain MG8 metabolites allows to optimize regenerative process, to reduce time of wound contraction and the formation of scar tissue, to full restore of the coat, so they can be modulators of the wound process, with a predominance of regeneration mechanisms

Fossil bacteria in permafrost evolutionarily adapted to low temperatures (-5ºC), modern probiotics bacteria are adapted to living in warm-blooded animals (37ºC). It was found that at -5ºC, the enzymatic activity of fossil bacteria Bacillus sp. MG8 is a minimal strain. At lowering the incubation temperature to -16ºC, the enzymatic activity of bacte-ria MG8 increases in 3 times, at the temperature 42ºC - in a 1.5times relative IP5832 strain probiotic bacteria Bacillus cereus. Fossil strain Bacillus sp. MG8 and probiotic bacterial strain B.cereus IP5832 at incubation temperature 37ºC practically don’t differ from each other in the enzymatic activity in vitro and toxicity in laboratory animals in vivo. Incubation fossil bacteria Bacillus sp. at -5ºC allows to reduce their toxicity in warm-blooded animals in 5 times in comparison with Bacillus cereus JP5832, and to increase immunostimulating effect in the doses from 0,005•106 to 50•106 microbial cells per mouse. The obtained data show that fossil saprophytic bacteria strain MG8 Bacillus sp. from permafrost are less toxic to modern mammals than even bacilli-probiotics for medical purposes.