The composition and the structure of microbial communities in areas of Arctic settlements were studied. The main attention has been given to microscopic fungi. As result of observation of 5 Arctic regions 117 species of microscopic fungi are revealed in soils and anthropogenic substrates. The identification was carried out with the use ofmycological and molecular genetic methods. Most ofspecies belong to the Ascomycotina. Genus Penicillium is characterized by the most species diversity (24 species). Most offungi are destructors of various materials and potential human pathogens. Dominant species are revealed. The distribution of microorganisms in the living and working areas of polar stations, as well as the adjacent areas are described. Black-colored fungi adapted to unfavorable environment are often the dominated group of microorganisms on soils and anthropogenic substrates. The shaping of soil microbiota was shown to be related to the anthropogenic impact. Considerable similarity of microbial communities composition in the soil and man-made substrates is fixed. As result of mycological analysis of contaminated soils 76 species of microscopic fungi were observed, but 41 species of them (53.9%) were identified in the areas of Arctic polar stations on the man-made materials. These species include the representatives of the genera Alternaria, Aspergillus, Aureobasidium, Chaetomium, Cladosporium, Exophiala, Geomyces, Humicola, Penicillium, Mucor, Phoma, Rhodotorula, Trichoderma and Ulocladium. The obtained data show a significant similarity in species composition of contaminated soils and anthropogenic substrates. Human activity contributes to the distribution of cosmopolitan species, including opportunistic fungi, in the Arctic region. The high numbers of organotrophic bacteria were revealed in soil samples. Some species of microorganisms produce the organic acids in an external environment that promotes the erosion of materials.

The article presents the results of mycological analysis of samples taken from open surfaces in residential and working areas of the Arctic and Antarctic Research Institute (AARI) station on the Bolshevik island of the Northern Land archipelago. 114 samples were studied during the expedition work from 2014 to 2016. In total, 47 species of micromycetes were detected in the course of the research. Most of the species (89%) were identified as Ascomycetes. Mucor group of fungi was composed 11% out of all the identified species. The genus Penicillium was the richest in species diversity (16 species). On the surface of materials in places of the increased moisture, there was an open growth of colonies of the Penicillium species. P. expansum was the dominant one, being noted during all the years of observations with the occurrence of about 60%. Among the frequently occurring species, there were P. brevicompactum, P. herqueri, P. purpurogenum and P. waksmanii, which were also noted during all the years of observation (the total occurrence exceeded 15%, although in some years it was much higher). Dark-colored fungus Cladosporium cladosporioides was also dominated species, which in some cases formed black mold on the surface of the materials. Among the potential pathogens, 41 species were registered. A comparison of the data obtained over the years indicates in 2016 the largest number of microfungi to be detected in the indoor environment of AARI station (35 species), whereas in 2014 and 2015 only 29 species of fungi were identified. The similarity of the identified groups of fungi over the years turned out to be quite high. Approximately 36% of microfungi (17 species) were observed annually, although their occurrence over the years varied significantly. Locally accumulation of micromycetes was noted in the indoor environment: household rooms, storage places, workrooms. In these cases, the microfungi colonized the colorful coating, synthetic materials, plywood. The formation of mycobiota in the studied areas is due to anthropogenic invasion of microfungi.

Antarctic station “Mirny” was the first Russian (Soviet) polar station in Antarctica. The anthropogenic impact on the primary ground and soil in the area around of this polar station took place more than 60 years. This is reflected in both the chemical composition of the soil and microbial communities. The article shows multiple increasing of the number of bacteria and microscopic fungi in anthropogenic contaminated soils. Contamination of soil leads to changes of the structure of the microbial community. An increasing proportion of mesophilic bacteria isolates (90%) was shown. The increasing share spores and reduced the proportion of microscopic fungi mycelia were observed. Statistical analysis showed that we have identified almost all of the expected species that live in anthropogenic substrates (42 species), as well as in the control soils (17 species). But we identified only a part of fungal diversity in contaminated soils (32 species). The increase in the number of fungal species in the area of the polar station “Mirny” was proved to be connected with the human activity and introduction of new species. Native species of microscopic fungi were found to be able to colonize new materials previously unavailable to them. They also can be agents of active biodegradation of anthropogenic materials. Among fungal species isolated from anthropogenic contaminated soil and anthropogenic substrates more than 80% can be attributed to opportunistic organisms. Therefore the total number of microorganisms (CFU), the structure of the microbial complexes, the species composition of communities, indicator species, morphology and volume of biomass can be considered as an index of changes in soil microbial complexes and primary soils