[Growth characteristics of microscopic fungi capable of growing actively under the conditions of the 4th unit of the Chernobyl Nuclear Power Plant]. / Rostovye kharakteristiki mikroskopicheskikh gribov, aktivno rastushchikh v usloviiakh 4-go bloka ChAES.

Growth parameters of fungi species which, from the preliminary data, were brought to those growing actively under the conditions of the Chernobyl NPP 4th unit have been studied in the presented work. Radial growth velocity, hyphal growth unit and intensity of the substrate colonization were such growth indices. All the investigations were carried out on two media--the wort agar, being of full value for fungi, and deficient agar limited as to major sources of nutrition. Two main types of population of the 4th unit rooms with the studied fungi have been found. The first method was characteristic of fungi capable to form the great number of small conidia and, respectively, fungal colonies, and to grow with low growth velocity, which was considerably higher at the initial stages than during the following ones. The second method was characterized by sufficiently high averaged growth velocity of mycelium; by its slowing down at the initial stages and its considerable increase in the process of further ontogenesis. Weak conidium formation was characteristic of this type; sometimes sporulation was lost at all. It has been shown that fungal species ascribed to those growing actively in the rooms of the unit 4 of the Chernobyl NPP are such ones, and they play the major part in the population and biodestruction of the building structures of the 4th unit.

[Comparative analysis of radial linear growth velocity of micromycetes isolated from different ecotopes]. / Sravnitel'nyi analiz skorosti radial'nogo rosta mikromitsetov, vydelennykh iz razlichnykh ékotopov.

The work aim was the discovering of peculiarities of microscopic fungi responding to radioactive pollution by growth velocity change. The linear growth velocity of a broad range of micromycetes was analyzed. They were chosen in such a way that every species, as far as possible, was presented by the strains isolated from radioactive polluted and clean regions. Most of the studied species were characterized by the absence of reliable growth velocity differences of strains of the same species growing on rich and starving media. Only two species--Aureobasidium pullulans and Penicillium spinulosum were the exception. Their growth velocities on malt-agar were much more then those on starving medium (1.7-3.6. times). Species Hormonema dematioides did not have reliable differences of growth velocity on optimal and starving media, but A. pullulans had this difference (2.3-3.6 times). It is supposed to use this observation to simplify identification of these species. Only strains within species Cladosporium sphaerospermum and especially P. funiculosum isolated from radioactive polluted ecotopes had growth velocity which was less then that of the strains from clean regions. The delay of growth velocity in such conditions can testify to adaptive change of metabolic processes of these strains. The strains which were characterized by delay of growth velocity existed at the substrates with high radioactive pollution for a long time.