The study of native microbial communities in natural environments is the key target of ecology. In this way the structural and morphological description is not sufficient because allows to mark out only the typical species between culturable microorganisms. The following extrapolation to cell activity in vitro should led to wrong conclusions.The ratio between the abundance of bacteria as determined by direct count under a microscope and that as determined by the plate methods in tundras ecosystems is often amounts to tens of thousands. A lot of unculturable cells could be methabollically active in these soils, thereby the comparative investigations of functional activity of microbial communities could give more reliable information about peculiarities of viable microbes in such environments. It was shown that in spite the fact that the majority of investigated Arctic permafrost sediments were formed in cold condition of tundra microbial ecosystems in permafrost are quite different from that ones in cryogenic tundras soils and have signs of some methabolical adaptations to long-extremal conditions. The data obtained give the evidences that permafrost is bio-stabilizing environment where some microbial and extracellular enzymes are considerably more stable in comparison with seasonally frozen terrestrial soils. The intriguing results of comparative research are the low ratio between indicies of cell quantity counted by direct microscopic and plate techniques and very high life potency indicies of microbial cells in subsoil permafrost. Another data were obtained for Antarctic permafrost sediments that is the subject for discussion.

Dr. Elena Vorobyova
Moscow State University
Soil Biology Department
Pyrieva str. 5-13-147
119285 Moscow, Russia
phone: +7-095-939-3179
fax:      +7-095-938-0672
e-mail:  lena@bio.soils.msu.su