[Growth characteristics of microscopic fungi capable of growing actively under the conditions of the 4th unit of the Chernobyl Nuclear Power Plant].

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.