Fungi in the surface layers of the air: their ecological role in the ecosystems and prospects of researches

The ecological role of aeromycota is discussed. The fungal aeroplankton of upper soil air layers could influence on other organisms (plants, animals, humans) and deposited on the soil surface. We investigated the content of the fungal propagules in the surface air and as the deposits on the soil surface at the forest and at the grass areas by fluorescent microscopy. In comparison with the investigation on the solid media the number of spores during direct examination was some orders of magnitude higher and amounts to hundreds of thousands spores per cubic meter. In seasonal dynamic the number of fungal spores in the air was usually higher at forest area and less on the grassy territories. The maximal deposition of fungal spores on the soil surface (4.1±0.4 mg/m2 per day) was marked in the autumn. According to our preliminary data, in rainwater occurred a significant concentration of fungal spores from the surface air.Работа выполнена при финансовой поддержке РФФИ (проект 15–04–02036)

Fungal biomass and species composition of cultivated microfungi in the soils of Eastern and Western Antarctica

Structure of fungal biomass and their distributions in the profiles of Antarctic soils has been examined. The biomass in these soils is low, but half of propagules are viable. The maximal value of fungal biomass (0.6± 0.10 mg/g soil) has been estimated in soils under mosses and lichens. In soils of regoliths and «stone roadways» a biomass of fungi was the lowest — less 0.3 mg/g of soil. In some profiles the highest content of fungal biomass was found in the horizons under topsoil. These features are not typical for zonal soils of nonextreme ecosystems. The abundance of cultivated microfungi in Antarctic soils was low (0.4×103 — 8.0×103 CFU/g soil). The majority of fungal species was isolated at +5 °C. The highest number of CFU was determined in soils with rich organic and moisture content. The dark-colored microfungi of genera Alternaria, Cladosporium, Doratomyces, Phoma etc. were predominantly isolated from the topsoil of «stone roadways»

The impact of low temperatures on the structure of the microbial biomass during the soil samples storage

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