Investigation of microbial communities of Antarctica soils is a very important field of research that expands our knowledge of microbial participation in primary soil formation and specific features of their communities in extreme habitats, and it is of considerable interest in directed search of for microorganisms as potential biotechnological objects. The results of long-term (2012–2017) complex studies on soil microbial communities of the Russian East Antarctica polar stations at Shirmakher oasis (Novolazarevskaya station), the Larsemann Hills (Progress station), and the Tala Hills (Molodezhnaya station) are presented in this review. The assessment of biomass of soil microorganisms by the methods of direct microscopy has been carried out for the first time for this region. The general amount of microbial biomass is small; the fungi dominate (77–99%). The unique features of Antarctic soils are the high content and morphological diversity of small forms of microorganisms: fungi are presented by mainly single-celled structures (small spores and yeasts), while bacteria by ultrafine (filtering) forms. At the same time, microorganisms can significantly contribute to such important ecological functions of soil as the emission of greenhouse gases, especially during the warm season with the stable positive temperatures of the soil. This should be considered during creation of models and forecasts of global warming. The use of various isolation techniques for the analysis of the soil microbial population, together with the succession approach, significantly expand the information about taxonomic diversity of cultivated fungi and bacteria in Antarctica soils.

The method of luminescent microscopy has been applied to study the structure of the microbial biomass of soils and soil-like bodies in East (the Thala Hills and Larsemann Hills oases) and West (Cape Burks, Hobbs coast) Antarctica. According to Soil Taxonomy , the studied soils mainly belong to the subgroups of Aquic Haploturbels, Typic Haploturbels, Typic Haplorthels, and Lithic Haplorthels. The major contribution to their microbial biomass belongs to fungi. The highest fungal biomass (up to 790 μg C/g soil) has been found in the soils with surface organic horizons in the form of thin moss/lichen litters, in which the development of fungal mycelium is most active. A larger part of fungal biomass (70–98%) is represented by spores. For the soils without vegetation cover, the accumulation of bacterial and fungal biomass takes place in the horizons under surface desert pavements. In the upper parts of the soils without vegetation cover and in the organic soil horizons, the major part (>60%) of fungal mycelium contains protective melanin pigments. Among bacteria, the high portion (up to 50%) of small filtering forms is observed. A considerable increase (up to 290.2 ± 27 μg C/g soil) in the fungal biomass owing to the development of yeasts has been shown for gley soils (gleyzems) developing from sapropel sediments under subaquatic conditions and for the algal–bacterial mat on the bottom of the lake (920.7 ± 46 μg C/g soil). The production of carbon dioxide by the soils varies from 0.47 to 2.34 μg C–CO 2 /(g day). The intensity of nitrogen fixation in the studied samples is generally low: from 0.08 to 55.85 ng С 2 Н 4 /(g day). The intensity of denitrification varies from 0.09 to 19.28 μg N–N 2 O/(g day).

The assessment of the microbial biomass structure in the soil samples from A and C horizons, stored at the temperature of +5 and -70°С was conducted by a luminescence method. For the samples from the humus layer a significant decrease of biomass during the cryostorage was revealed. However, in the sample from the mineral layer at the same storage conditions such a decrease occurred in a lesser degree. The decrease of fungi mycelium length was observed in the sample, which was stored at the temperature -70°С. Also, the decrease of the number of fungi spores with large diameter ( d > 5 mkm) and the absence of the largest spores ( d > 7 mkm) was observed. The mycelium length of the pure culture of Cadophora novi-eboraci fungi was a bit decreased after the storage of samples at +5°С. Under conditions of negative temperatures (-18 and -80ºС) the mycelium length was decreased by 28% during the first days, and by 32% on the 14-th day of the incubation. The data obtained stipulate that the storage of samples under conditions of negative temperatures leads to the decrease of biomass and number of microorganisms within the soil. Therefore, it is not recommended to store soil samples under conditions of negative temperatures if it is planned to assess the structure of microbial biomass by the direct method of luminescent microscopy.

Elevated temperatures differentially affect the development of cultivated microfungal assemblages, including species potentially pathogenic for humans, in various natural and anthropogenic soils. For that reason it is important to know whether the relative abundance and diversity of fungal pathogenic species increase at elevated soil temperatures. We compared successional changes in microfungal species diversity in natural (Histic Leptosol, Umbric Albeluvisol) and anthropogenic (Urbic Technosol) soils of the boreal zone of European Russia at temperatures of 10, 20, 30, and 35 degrees C, and at a water holding capacity of 60% using the soil dilution plate method. The greatest fungal diversity was detected at the lowest but common temperature (10 degrees C) in the investigated regions. The most significant changes in the diversity of fungal assemblages in the process of succession occurred at 20 degrees C. Elevated soil temperatures (30 and 35 degrees C) induced a drastic decrease in species diversity compared with what was observed at 10 degrees C.During the successions, microfungal assemblages in both types of natural soils had the most pronounced differences in species composition at minimal (10 degrees C) and maximal (35 degrees C) soil temperatures. In the anthropogenic soil, microfungal communities at varying stages of succession were more similar at different temperatures, with the exception of the final stages of succession at the highest temperature of 35 degrees C. Independently of soil type, elevated temperature increased (up to 40-90%) the relative abundance of potentially pathogenic microfungal species dangerous for humans. Potentially pathogenic Aspergillus fumigates was dominant in the natural soils, while Scedosporium aurantiacum dominated in the urban soil. Elevated soil temperatures in combination with high humidity due to climate warming may drastically accelerate the development of potentially pathogenic microfungal species. (C) 2016 Elsevier GmbH. All rights reserved.

The distribution of the fungal biomass and diversity of cultivated microscopic fungi in the profiles of some soils from East (Progress Station, valleys of the Larsemann Hills oasis) and West (Russkaya Station, the Marie Byrd Land) Antarctica regions were studied. The structure of the biomass (spore/mycelium and live cells/dead cells) was analyzed by fluorescence microscopy with staining using a set of coloring agents: calcofluor white, ethidium bromide, and fluorescein diacetate. The species composition of the cultivated microscopic fungi was determined on Czapek’s medium. The fungal biomass in the soils studied is not high (on the average, 0.3 mg/g of soil); the greatest biomass (0.6 mg/g) was found in the soil samples with plant residues. The fungal biomass is mainly (to 70%) represented by small (to 2.5 μm) spores. About half of the fungal biomass is composed of living cells. There are differences in the distribution of the fungal biomass within the profiles of different primitive soils. In the soil samples taken under mosses and lichens, the maximal biomass was registered in the top soil horizons. In the soils with the peat horizon under stone pavements , the greatest fungal biomass was registered in the subsurface horizons. Thirty-eight species of cultivated microscopic fungi were isolated from the soils studied. Species of the genus Penicillium and Phoma herbarum predominated.

В настоящем обзоре приведены результаты многолетних исследований сотрудников кафедры биологии почв факультета почвоведения МГУ, связанные с изучением одной из главных функций почвенных микроорганизмов – осуществление и поддержание круговорота веществ и энергии в биосфере. Приведены данные по численности и запасам микробной биомассы в разных типах почв, проанализированы результаты системного подхода к изучению структурно-функциональной организации микробных сообществ почв, показана роль эукариотных и прокариотных микроорганизмов в циклах углерода и азота. Для осуществления круговорота химических элементов в наземных экосистемах требуются высокая численность и разнообразие форм микроорганизмов, но при этом встает вопрос о сохранении микробов в почвах в жизнеспособном состоянии. Приведены новые данные об одном из способов переживания бактерий в почвах в виде наноформ; рассмотрены такие природные банки микроорганизмов, как торфяники и палеопочвы, в которых микробы могут сохраняться в течение десятков тысяч лет.

The results of long-term investigations performed by researchers from the Department of Soil Biology at the Faculty of Soil Science of Moscow State University into one of the major functions of soil microorganisms—sustenance of the turnover of matter and energy in the biosphere—are discussed. Data on the population densities of soil microbes and on the microbial biomass in different types of soils are presented. The systemic approach has been applied to study the structural-functional organization of the soil microbial communities. The role of eukaryotic and prokaryotic microorganisms in the carbon and nitrogen cycles is elucidated. It is argued that the high population density and diversity of microorganisms are necessary to maintain the turnover of chemical elements in terrestrial ecosystems. The viability of microbes stored in the soils is important. New data on the preservation and survival of bacteria in nanoforms are presented. It is shown that peatlands and paleosols are natural banks, where microbes can be preserved in a viable state for tens of thousands years.

Выявлены различия показателей биологической активности верхних горизонтов городского урбанозема (г. Москва, СЗАО, р-н Тушино), где опад регулярно изымается и подстилка отсутствует, и фоновой ненарушенной дерново-подзолистой почвы с подстилкой. В исследованных почвах уровни и динамика ферментативной целлюлазной активности были сопоставимы, значения возрастали от весны к осени, что было более резко выражено в урбаноземе осенью во время листопада. Сезонная динамика эмиссии СО2 при увлажнении в урбаноземе была сходна с фоновой почвой, но абсолютные значения существенно меньше в летний и осенний периоды. Методом субстрат-индуцированного дыхания выявлен отклик на внесение целлюлозы в обеих почвах, однако в урбаноземе возрастание эмиссии CO2 было в 1.5-2 раза меньше. При внесении опада липы (Tilia cordata Mill.) в контактном с опадом слое почвы (0.5 см) целлюлазная активность возрастала, но в урбаноземе эта реакция была менее выражена, чем в дерново-подзолистой почве. Увеличение эмиссии СО2 при добавлении целлюлозы в контактном с опадом слое, наоборот, было более выражено в урбаноземе и дольше сохранялось.

The parameters of the biological activity in the upper horizons of an urban soil in Tushino (the northwestern administrative district of Moscow) without the litter horizon because of the regular removal of the plant litter and an undisturbed background Albic Retisol with the litter horizon were compared. In the studied soils, the levels and dynamics of the cellulolytic activity were comparable and generally increased from the spring to the fall seasons. This increase was more pronounced in the urban soil during the leaf fall. The seasonal dynamic of the CO 2 emission in the urban soil (upon its moistening) was similar to that in the background soil, though the absolute values were significantly lower in the summer and fall seasons. The method of substrate-induced respiration (SIR) showed that the rise in the CO 2 emission in response to the addition of cellulose in the urban soil was 1.5–2.0 times lower than that in the background soil. The increase in the cellulolytic activity upon the application of lime leaves ( Tilia cordata Mill.) in the uppermost 5 mm of the urban soil (immediately under the leaves) was also less pronounced than that in the natural background soil. At the same time, the increase in the CO 2 emission upon the addition of cellulose into this layer was more pronounced and continued for a longer time in the urban soil.

The aim of our study was to examine the ability of soil fungal communities to serve as indicators of human impact in anthropogenically transformed soils of medieval settlements. The investigations were carried out as long-term studies (from 1999 through 2013) of fungal communities in habitation deposits of medieval settlements (7th–11th centuries AD) in the European part of Russia (Komi Republic, Smolensk Region, Samara Region, Stavropol Region), Tuva Republic and South-Western Kazakhstan. Total fungal biomass and biomass structure in soils were evaluated by using luminescent microscopy with Calcofluor white. Isolation of fungal trophic groups was performed on different solid media by means of the soil dilution plate method and by the bite technique. For the description of microfungal communities, use was made of such indexes as spore/mycelium ratio in fungal biomass, species diversity and species composition. The examined habitation deposits of ancient settlements differed from the horizons of the surrounding natural soils because of a larger share of fungal spores in fungal biomass, more mosaic distribution of microfungal communities, as well as differences in species composition and in dominant microfungal species. For reconstructions of certain types of human activities, use can be made of phytopathogenic, keratinophilic, and coprophylous fungi serving as bioindicators. The increase of phytopathogenic fungi (namely Fusarium species) in the cultural layer presumably marked grain pit locations. Accumulation of keratinophilic fungi could be observed in domestic animal shelters, as well as in household pits, and storage sites of wool, skins, and feathers. Increased abundance of keratinophilic fungi was most obvious in the sites of ancient streets and dwelling floors. The increased content of coprophylous fungi was indicative of accumulation of dung on certain plots. There was a distinct correlation between presence of both these fungal groups and the assumption that the sites in question were occupied by herbivores in the past. The mycological properties of soil offer information about ancient human–landscape interaction and can be used in paleo-environmental reconstructions of medieval settlements.

This review covers the history of the mycological studies performed at Pertsov White Sea Biological Station, Moscow State University (WSBS MSU). The WSBS was established more than 70 years ago; presently, it is one of the main divisions of the university, where numerous educational and research marine programs are fulfilled. Mycological studies have been performed here for more than half a century, focusing on biodiversity and ecology of marine, littoral, and soil fungi and fungi-like protists. Various research projects resulted as a number of scientific publications, diploma (MSc) theses, and dissertations. Presently, WSBS MSU and its vicinity is the northernmost area researching the best in regard to mycobiota. However, a number of blind spots still exist; thus, the future studies in this region should focus on diversity and biology of epiphyte fungi, ecology of fungi and fungi-like protists, and on fungi phylogeny.