Effect of the methodology of studies on the structure of the microorganisms communities in the forest soil

Two different communities of microorganisms were identified in soils by application of the classical method of fungi isolation (soil dilution, culturing on artificial media, morphotyping) and a molecular method (extraction of the environmental DNA, amplification with universal primers NS1 and NS2, cloning and sequencing of representative clones). No organisms were common to both communities. Apart from rare representatives of the Animalia, communities included single fungus-like Eucarya belonging to the Protista, Class Oomycota, and numerous fungi belonging to Chytridiotnycota, Zygomycota, Ascomycota and Basidionlycota orders. In total, 88 species were identified in four soil samples. Fungi were mostly Ascomycota. The classical method was particularly effective in detection of fungi important for creation of phytosanitary conditions of soil, i.e. antagonists (Penicillium, Tolypodadium and Trichoderma) and potential stimulants (dark-pigmented Hormiactis candida, Humicola spp. and Phialophora spp.) of phytopathogens (including the common forest genera Armillaria and Heterobasidion). Application of the classical method allowed the detection of mycorrhizal Ascomycota from the genus Oidiodendron. Application of the molecular method allowed the detection of 13 mycorrhizal Basidiomycota. Although primers NS1 and NS2 were designed from a match with DNA of culturable organisms, they also amplified the DNA of non-culturable organisms. This emphasizes their potential usefulness in studies of the biodiversity of microorganisms in environmental samples. The shortage of reference sequences in the database discourages use of the 18S rDNA region in studies on fungal communities. The studies on the biodiversity of microorganisms need the application of a few independent methods of detection and identification.