Survival of micromycetes and actinobacteria under conditions of long-term natural cryopreservation

Almost all of the investigated samples of the Arctic and Antarctic permafro st sediments of different genesis with ages from 5-10 thousand to 2-3 milli on years were found to contain viable micromycete and bacterial cells. The maximum amounts of viable cells of fungi (up to 10(4) CFU/g air-dried sampl e) and bacteria (up to 10(7)-10(9) CFU/g air-dried sample) were present in fine peaty sediment samples taken from different depths. The identified mic romycetes belonged to more than 20 genera of the divisions Basidiomycota, A scomycota, and Zygomycota, and some represented mitosporic fungi. Thawing t he samples at 35 and 52 degreesC allowed the number of detected fungal gene ra to be increased by more than 30%. Aerobic heterotrophic prokaryotes were dominated by coryneform, nocardioform, and spore-forming microorganisms of the order Actinomycetales. Analysis of the isolated fungi and actinomycete s showed that most of them originated from the microbial communities of anc ient terrestrial biocenoses.