[Utilization of different carbon sources by soil and endophytic strains of Penicillium funiculosum Thom].

The ability of soil and endophytic strains of P. funiculosum to accumulate biomass under cultivation conditions in media containing carbon sources from mono- to polysaccharides has been studied. It has been shown that the most favorable carbon sources for the studied strains were maltose, sucrose, xylose, fructose, pectin, less assimilated lactose, arabinose, and especially microcrystalline cellulose. Significant differences in the level of biomass accumulation between soil and endophytic strains of this species in most cases were not established.

[Utilization of carbon sources by Fusarium poae (Peck) Wollenw. Strains from different trophic groups].

It was shown that saprophytic (soil), endophytic and plant pathogenic strains of F. poae under cultivation conditions in the media containing carbon sources from mono- to polysaccharides had different abilities to use them and to accumulate biomass. Maltose, xylose, fructose, pectin were the most favorable carbon sources for the studied strains; less assimilated lactose, arabinose, and especially microcrystalline cellulose were less assimilated. It was found that endophytes and plant pathogens accumulated biomass equally, while soil strains had low ability for that.

[Survivability of some black yeast-like fungal species under UV-irradiation]. / Vyzhivaemost' nekotorykh vidov chernykh drozhzhepodobnykh gribov pri vozdeistvii UF-luchei.

The survival of 4 species (14 strains) of black-pigmented yeast-like fungi, isolated from radioactive polluted ecotopes, after UV-irradiation has been studied. Their survival was different in the limits of 3 orders from 0.7 to 0.0001% and was described by the exponential composite exponential and composite sigmoid types of dose curves. Essential heterogeneity for the level and character of survival after UV-irradiation of conidia Aureobasidium pullulans, Hormonema dematioides, Exophiala cf. jeanselmei and Exophiala sp. has been presented.

[Statistical criterium of pollution heterogeneity in the research of biotic factors of radionuclides migration]. / Statisticheskii kriterii geterogennosti zagriazneniia pri issledovanii bioticheskikh faktorov migratsii radionuklidov.

The nature of the radionuclide contamination resulting from Chernobyl disaster is in its spatial and aggregate heterogeneity determined by the interaction of systematic and incidental factors. To study the radionuclide migration in the soil-plant system, an independent statistical index of contamination heterogeneity H = RAsAp is proposed which is calculated as a Brave-Pirsens coefficient of linear correlation between radioactivity of soil and dry biomass of plants grown on it and which allows to determine relative range of contamination that appears in the form of "hot particles". An adequacy of this index is substantiated, and it is used to analyze the experimental results on radionuclide migration.

[The dynamics of the fungal mycelial content in the soils of stationary posts in a 30-kilometer zone around the Chernobyl Atomic Electric Power Station]. / Dinamika soderzhaniia gribnogo mitseliia v pochvakh statsionarov 30-kilometrovoi zony ChAES.

The paper deals with mycobiota of radionuclide-polluted soils of seven stationary posts in the 30-kilometer zone of the Chernobyl NPP and one in the vicinities of Kiev (Feofaniia). The lengths of light-and dark-coloured fungal mycelium were determined in the soil under study by the method of membrane filters for 1987-1989. Data obtained have been analyzed with the account of the radioactivity level of the soil samples, season and depth of the sampling horizon. The dynamics of mycelium content in soils has been traced which evidences for its seasonal changes and prevalence of dark-pigmented mycelium at the beginning which then was changed by predominance of light-coloured mycelium. It is supposed that radioactive contamination of soil is one of considerable components of the whole complex of ecological factors which determine the dynamics of fungal mycelium content in soil.

[Complexes of soil micromycetes in the area of the influence of the Chernobyl Atomic Electric Power Station]. / Kompleksy pochvennykh mikrokitsetov v zone vliianiia Chernobyl'skoi AES.

Complexes of soil micromycetes in the Chernobyl 30-km zone of the Ukrainian Polesye were studied for 1986-1989 with regard for such ecological parameters as the level of radiation contamination, a particular observation site, depth of soil horizon and season. As a result of the study correlation pleiads of soil micromycete complexes have been revealed with their structure and fungal genera characteristic of such complexes determined. The overwhelming majority of correlation pleiads of fungal complexes are attributed to complex-organized ones and this indicated high radioresistance of mycobiota in the studied, soils. Melanine-containing genera of fungi rank among the first in formation of correlation pleiads of soil micromycete complexes.

[The interaction of soil micromycetes with "hot" particles in a model system]. / Vzaimodeistvie pochvennykh mikromitsetov s "goriachimi" chastitsami v model'noi sisteme.

A model system which permits observing for a long time and fixing interaction of fungi with a radiation source has been created on the basis of an isolated "hot" particle, deficient mineral medium (saccharose content 60 mg/l) and suspension of fungal conidia. Five species (six strains) of micromycetes isolated from radionuclide-contaminated soils and fifteen "hot" particles have been tested. It has been found out for the first time that Cladosporium cladosporioides and Penicillium roseo-purpureum are able actively overgrow "hot" particles whose radioactivity did not exceed 3.1-1.0(-7) Ci by gamma-spectrum and to destroy them 50-150 days later. Certain changes in morphology of fungi-destructors of "hot" particles are revealed. A problem on ecological significance of the found phenomenon is discussed.