Vol 57, No 4 (2023)

The number and diversity of cultivated microscopic fungi isolated from seawater, littoral and supralittoral soil on the coast of the Barents Sea were studied. Communities of microfungi are mainly represented by facultative marine fungi of terrigenous origin. The isolates mainly belonged to anamorphic fungi of the department Ascomycota and are represented by the genera Penicillium, Aspergillus, Talaromyces, Trichoderma, Acremonium etc., characteristic of the cold northern seas. The frequently found species in the study area were Aspergillus brasiliensis, Penicillium hirsutum, P. glabrum, P. spinulosum, P.  janczewskii, Trichoderma koningii, T. viride, Talaromyces purpureogenus. The number of fungi in the supralittoral soil is two to three orders of magnitude higher than in the soils of the littoral zone and averaged from 4 to 13 thousand CFU/g. In sea water, the number of fungi was only a few units per ml. The maximum number of saccharolytic fungi was noted in the soils of the supralittoral zone. In the soils of the littoral and sea water, the number of hydrocarbon-oxidizing fungi varied from 52.5 to 143.3 CFU/g and from 0 to 4 CFU/ml, respectively. The number of saccharolytics varied from 0 to 113 CFU/g in the littoral soil and from 0 to 3 CFU/mL in sea water in all the studied areas, except for the most polluted ones, where it reached values of 200 CFU/g. An increase in the proportion of saccharolytic fungi in sea water and littoral may indicate anthropogenic pollution of the area, including hydrocarbons and other organic compounds. The urbanized areas of the Kola Bay with a high anthropogenic load were characterized by a richer species diversity and an increase in the proportion of pathogenic and opportunistic forms of microscopic fungi. A high level of hydrocarbon pollution negatively affected the number of saccharolytic fungi, while lower values of hydrocarbon content did not affect the number of saccharolytics. The number of fungi grown on Czapek’s mineral medium decreased as the amount of hydrocarbons both in sea water and in the littoral zone increased, which may indicate a high vulnerability of marine microfungi to pollution.

It is shown that in North Asia (Urals, Siberia, Far East) the genus Trichaptum is represented by four widespread sympatric species (Trichaptum abietinum, T. biforme, T.  fuscoviolaceum, T. laricinum) and T. quercinum found in the Far East. The geographic range of T.  fuscoviolaceum, T. abietinum, T. biforme cover the whole of North Asia, whereas T. laricinum is absent in the Far East. The revealed sympatric nature of species is based on their predominant use of wood various coniferous (T.  fuscoviolaceum, T. abietinum, T. laricinum) and deciduous (T. biforme) tree species. The widest trophic niche is in T.  fuscoviolaceum and it overlaps by 70–80% with the niches of T. abietinum, T. laricinum. The narrowest trophic niche that does not overlap with other species of the genus is in T. biforme. The trophic spectra and preferences of all species in North Asia are close to those in Europe, and it shows stability and species specificity of these ecological characteristics. Phylogenetically, T. abietinum and T.  fuscoviolaceum are the closest in ITS and LSU rDNA regions, while T. biforme and T. laricinum are strongly and equally distant from each other and from T. abietinum and T.  fuscoviolaceum. During ITS and LSU clustering, the sequences are grouped in full accordance with the hymenophore structure of the fungi from which they were isolated; the same groups also include sequences of the corresponding fungi from Europe, China, and North America. This shows that in T.  fuscoviolaceum, T. abietinum, T. biforme, T. laricinum, the structure of the hymenophore is a good diagnostic species character, and also that their North Asian populations do not show significant differences from European and North American populations. A database on diversity, distribution, ecology of fungi of the genus Trichaptum in North Asia has been uploaded to GBIF for public access.

The paper continues a series of publications devoted to the new finds of macrofungi (Ascomycota, Basidiomycota) in regions of the Russian Far East. A total of 77 species of macromycetes are reported for the first time from 7 administrative units of the Russian Far East: Amur Oblast, Jewish Autonomous Oblast, Magadan Oblast, Sakhalin Oblast, Kamchatka Krai, Khabarovsk Krai and Primorskiy Krai. 13 species are reported as the first records for the Russian Far East, and 4 (Calycina subtilis, Cistella fugiens, Lachnum roridum and Lasiobelonium horridulum) are new for Russia. For some of the rare species, notes are given about the main differences in morphology and ecology, about the features of distribution. The identification of Jahnoporus brachiatus is confirmed by molecular genetic data, and this specimen was isolated into pure culture. The material was deposited in ABGI, LE, MAG, SVER, TOB, VLA herbaria as well as in the Yu. Rebriev (YuR) and A. Shiryaev (Shiryaev) personal collections.

The strain of fungus СР4 capable of degrading microcystin – LR (MC-LR) was isolated from the bottom sediments of Sestroretsky Razliv Lake. Based on DNA ITS sequencing and morphological analysis, the CP4 strain was identified as Penicillium verrucosum. The decrease in the content of MC-LR during the cultivation of strain СР4 from 0.64 μg/mL to 0.31 μg/mL occurs mainly due to biodegradation and, to a lesser extent, due to the sorption of the toxin by fungal cells. The method of biotesting (Daphnia magna) showed a decrease in the toxicity of the culture liquid in the process of MC-LR biodegradation by the strain СР4. The obtained results allow us to consider Penicillium verrucosum СР4 as a promising strain for mycoremediation of water bodies contaminated with microcystins.

Proteolytic cleavage of fibrin and fibrinogen under the action of proteases of microfungi Aspergillus alliaceus 7dN1 and A. terreus 2 was carried out. It was shown that both enzymes can have strong α-fibrinogenase and moderate β-fibrinogenase activity, practically without affecting the γ-chains of these molecules. The products of cleavage in the time interval up to 60 min are polypeptides with a molecular weight of 15 kDa or less.