The review examines the results of studies of the last decade on the co-cultivation of fungi and microalgae. It outlines the mechanisms of interaction between fungi and microscopic algae during associative cultivation and briefly discusses the methods for the formation of flocs. Key importance for biotechnology is the ability of fungi and algae to form granules (floccules), which are easy to separate from the culture liquid. The synergistic effect of these relationships results in a higher level of biomass accumulation, synthesis of lipids, polyunsaturated fatty acids, and other metabolites, as well as the removal of various pollutants from wastewater. By selecting specific strains and optimizing cultivation conditions, it is possible to enhance the composition of the resulting products. So far, mostly successful laboratory experiments have been carried out in this direction, which need to be expanded and transferred to production projects. For large-scale application of these systems, it is necessary to continue research into the mechanisms of interaction between fungi and microalgae, their metabolism, regulation of biosynthetic processes using modern methods of metabolomics and proteomics, and to develop engineering solutions for their cultivation.

Goodyera repens is an orchid, widespread and abundant in the coniferous forests of the northern hemisphere. Along with other members of Orchidaceae, in natural conditions it exists in obligate mycorrhizal symbiosis. Despite a long history of study, no data on the mycobiota associated with the root system of this species have been obtained for populations growing in Russia. It is therefore necessary to assess the entire diversity of fungal associates, including non-cultivated species, as well as to obtain quantitative characteristics and evaluate the geographic specificity of fungal communities. In this work, the mycobiota of the root system of G. repens growing in the Leningrad and Moscow Regions and Karachay-Cherkess Republic was analysed qualitatively and quantitatively for the first time using high-throughput sequencing. A total of 438 operational taxonomic units were identified, with the majority belonging to the subdivision Basidiomycota. The quantitative predominance of sequences of the genera Russula, Ceratobasidium, Piloderma, Mycena, and Tomentella was observed. Significant differences between fungal communities of soil and the root system of G. repens were established in all studied regions. The regional specificity of the taxonomic composition of the mycobiota was demonstrated. The taxa spectrum of the samples from Karachay-Cherkessia differed significantly from that of the Leningrad and Moscow Regions, while no notable difference was observed between the latter two. With regard to the distribution of ecological groups of fungi, no significant differences were found between the regions.

The number, species composition, and taxonomic structure of fungal biota in the groundwater of natural springs and wells in Moscow and Moscow oblast were determined by the сultural method. The number of fungi was low, on average, from 10 to 300 colony-forming units (CFU) in one liter of water. From the water of one source or well, 6–16 species were isolated, and in total, 46 species were isolated from six objects studied. These were representatives of phylum Mucoromycota, class Mucoromycetes (Absidia cylindrospora var. nigra, Mucor circinelloides, M. hiemalis, and Rhizopus stolonifer), phylum Ascomycota, class Eurotiomycetes (15 species of the genera Aspergillus and Penicillium), Sordariomycetes (13 species of the genera Acremonium, Chaetomium, Fusarium, Myrothecium, Plectosphaerella, and Trichoderma), Dothidiomycetes (Alternaria alternata, A. nobilis, Amorocoelophoma cassia, Cladosporium cladosporioides, and C. sphaerospermum) and Saccharomycetes (Candida solani, C. zeylanoides, and Galactomyces pseudocandidus), and the phylum Basidiomycota, class Tremellomycetes (Mrakia gelida and Vishniacozyma victoriae) and Agaricomycetes (Phlebia acerina, Psathyrella candolleana, and Thanatephorus cucumeris). The established taxonomic structure of fungal biota in the waters of natural springs and wells of the Moscow metropolis is similar to that found in the groundwater of other regions, including groundwater at the depths of several hundred meters. The possibilities of adaptation of micromycetes to existence in groundwater, the sources of its contamination, and the need for mycological criteria for assessing water quality are discussed.

A study of the distribution of methane cycle microbial communities in the upper layers of bottom sediments above large hydrocarbon reservoirs in the South Kara petroleum region of the West Siberian Province revealed the presence in these layers of both aerobic methanotrophic bacteria and anaerobic methanogenic archaea, as well as numerous heterotrophic microorganisms of various phylogenetic groups. Research was carried out in the Baydaratskaya Bay and in the east of the Pukhuchan Depression (southern part of the Kara Sea). Aerobic methanotrophic bacteria belonged to the families Methyloligellaceae, Methylophagaceae and Methylomonaceae were detected in the surface oxidized layers (0–2 cm, Eh from 60 to 175 mV) of bottom sediments. Moreover, representatives of Methyloligellaceae were found in quite significant amount (1.52–2.61

The study of the dynamics of mycobiota during composting the cow manure and wheat straw was carried out, using DNA barcoding and cultural method. Fungi of phyla Ascomycota, Basidiomycota, Mortierellomycota, Chytridiomycota, Rozellomycota and Aphelidiomycota have been found using DNA barcoding. Cultural (plating) method identified fungi of phyla Ascomycota, Basidiomycota, Mucoromycota. All the orders of fungi determined by the plating method, with the exception of Saccharomycetales in Ascomycota and Mucorales in Mucoromycota, have been also discovered using DNA barcoding, but many other orders have been identified using the latter method. The coincidence of the species detected by both methods was very rare. The changes in the number of colony-forming and operational-taxonomic units of taxa of different levels have been observed during the transformation of manure with straw into compost. The DNA barcoding allowed to identify more fully the changes in the taxonomic and ecological-trophic structure of the fungal community during composting of manure and straw. They were manifested in a significant increase in the representation of basidiomycetes, especially Coprinus spp., Coprinellus spp., in compost, capable to transform lignin, complex organic substances of manure, and a decrease of the fraction of abundantly spore-bearing "sugars" and cellulolytic ascomycetes predominating in the initial substrates: Sordariomycetes in manure and Dothideomycetes in straw. Significant rearrangements occurred during composting in the composition of coprophilic, epiphytic, and phytopathogenic fungi. The importance of toxin-forming, allergenic, and thermophilic species of fungi that pose a danger to human health, and the possibility of assessing the readiness of compost for application to the soil as a biofertilizer, taking into account data on mycobiota, have been discussed.

Special enzymes are necessary for producing gluten-free foods, and specific proteolytic enzymes with gluten-degrading activity may be used as oral treatments for celiac disease. Enzymes of the kind were sought, identified, and preliminarily characterized in two strains of the alkaliphilic microscopic fungi Sodiomyces alkalinus and S. magadiensis. Post-glutamine cleaving activity was for the first time observed in the strains along with proline-cleaving activities of dipeptidyl peptidase 4 (DPP4) and proline aminopeptidase (PAP), allowing efficient hydrolysis of both proline/glutamine-rich gluten peptides and whole gluten. The optimal pH and pH-dependent stability were determined for the peptidases in question. All of the enzymes shown to cleave the prolyne/glutamine-containing bonds were assigned to the serine peptidase group and were found to be stable in moderately acidic and alkaline conditions. Owing to their activities, the peptidases are promising as tools to produce gluten-free foods and to design diets for gluten-intolerant patients.

Abstract Members of Ceratobasidiaceae family (more commonly known by its anamorphic name “rhizoctonias”) possess a variety of nutritional modes: plant pathogens, saprotrophs, endophytes and symbionts of orchid mycorrhiza. Links between nutritional modes and taxonomy of these fungi as well as their specificity towards plant host is still ambiguous. The scope of the present study was to explore biodiversity of ceratobasidioid mycobionts of sciophytic terrestrial orchid Goodyera repens, search for evolutionary stable clades within mycobionts of Goodyerinae subtribe uniform by plant host or geographic region and to establish possible connection between ceratobasidioid nutritional modes and morphological characteristics. We consider G. repens a generalist associated with a wide range of distantly related mycobionts. Two unidentified Ceratobasidium species and Thanatephorus ochraceus are reported from G. repens roots for the first time. Ceratobasidiaceae tend to form stable clades specific to either temperate or tropical region. Morphological characteristics of pathogenic and mycorrhizal rhizoctonia isolates tend to form a variety of transitional forms to correlate with nutritional mode.

Changes in the taxonomic structure of the fungal community during the processing of cow manure with straw using Eisenia fetida worms have been studied using fundamentally different methods—cultural and metabarcoding (by amplification and high-performance sequencing of ITS2 rDNA). Significantly more fungal taxa have been identified in substrates and vermicompost using metabarcoding than by the plating method (66 and 33 species, respectively). Single species have been identified simultaneously by both methods. The method of metabarcoding has revealed the operational taxonomic units (OTUs) of Ascomycota, Basidiomycota, Mortierellomycota, Chytridiomycota, Glomeromycota, Basidiobolomycota, Rozellomycota, and Aphelidiomycota; fungi from Ascomycota, Basidiomycota, and Mucoromycota were isolated by the culture method. The species richness of the community decreased during the first 10–20 days of substrate processing, then grew and reached maximum values in the vermicompost (60 days). Both methods showed the dominance of ascomycetes at all stages of transformation of substrates by E. fetida. Metabarcoding showed the dominance of Sordariomycetes of the order Sordariales (48–53

— Increasing terrestrial ecosystem carbon sink is an effective way to mitigate the rise of atmospheric carbon dioxide (CO 2 ) concentration and achieve the goal of “carbon neutrality”. Mycorrhizal fungi are beneficial microorganisms that can form symbiotic relationships with 90% of plants in terrestrial ecosystems, and the symbiont contributes significantly to soil and plant carbon sink. In the review, we take arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF), which are the most extensively studied currently, as the narrative objects, and discuss the carbon sink enhancement potential of mycorrhizal fungi from the following four aspects. The first, mycorrhizal fungi indirectly increase the plant carbon sink by promoting photosynthesis and increasing biomass in the host plant, and this advantage can be maintained even under stressful conditions. The second, the process of carbon source transportation between AMF-plant symbionts and EMF-plant symbionts is described in this paper. The third, review describes that mycorrhizal fungi contribute to soil carbon sink by increasing carbon input as well as decreasing carbon output. The fourth, we point out the shortcomings of the current study and provide a prospect for future research, with the aim to provide theoretical support for increasing terrestrial carbon sink.

На основе культурального метода и высокопроизводительного секвенирования ITS2 участка рДНК определена численность колониеобразующих единиц (КОЕ), таксономическая структура и видовое богатство грибных сообществ в донных грунтах озера Байкал с глубин от 9 до 178 м. Выявлено 215 видов, 138 родов, 50 порядков, 22 класса, 6 отделов - Ascomycota, Basidiomycota, Mucoromycota, Mortierellomycota, Chytridiomycota, Glomeromycota. Только ДНК-баркодинг позволил обнаружить представителей отделов Chytridiomycota, Glomeromycota и Rozellomycota. Культуральными методами и высокопроизводительным секвенированием ITS2 участка рДНК в грунтах выявлено 77 и 146 видов соответственно, и только восемь видов установлено обоими подходами. Большая часть нуклеотидных последовательностей не была идентифирована до уровня семейств и видов. В составе микобиоты грунтов есть представители различных эколого-трофических групп - сапротрофов, патогенов, симбиотрофов. Это преимущественно психротолерантные организмы, среди них есть факультативно-анаэробные виды. Установлены изменения таксономической структуры грибных сообществ в зависимости от глубины и виды, способные функционировать в грунтах. Это, в частности, Pseudeurotium bakeri, Pseudeurotium hygrophilum, Pseudogymnoascus pannorum, Pseudogymnoascus roseus, Trichoderma hamatum, Trichoderma harzianum, Trichoderma lixii, Trichoderma polysporum, Penicillium glandicola, Penicillium swiecickii, виды родов Rhizophydium, Fusarium, Daldinia, Mortierella, Coniochaeta, Cystobasidium, Mrakia, Rhodothorula, Solicoccozyma и ряд других. Создана коллекция штаммов грибов, изолированных из донных грунтов Байкала. Based on the culture method and high-performance sequencing of the ITS2 rDNA site, the number of colony-forming units (CFU), taxonomic structure and species richness of fungal communities in the bottom ground of Lake Baikal from depths from 9 to 178 m were determined. 215 species of 138 genera of 50 orders of 22 classes of 6 divisions - Ascomycota, Basidiomycota, Mucoromycota, Mortierellomycota, Chytridiomycota, Glomeromycota have been identified. Only DNA barcoding allowed to detect representatives of the Phyla of Chytridiomycota, Glomeromycota and Rozellomycota. The cultural method and high-performance sequencing of the ITS2 rDNA site in the soil revealed 77 and 146 species, respectively, and only 8 species were established by both approaches. Most of the nucleotide sequences have not been identified to the level of families and species. There are representatives of various ecological and trophic groups - saprotrophs, pathogens, symbiotrophs in the mycobiota of the bottom grounds. These are mainly psychrotolerant organisms, among them there are facultative anaerobic species. Changes in the taxonomic structure of fungal communities depending on the depth and species, and able to function in soils, have been established. These are, in particular, Pseudeurotium bakeri, Pseudeurotium hygrophilum, Pseudogymnoascus pannorum, Pseudogymnoascus roseus, Trichoderma hamatum, Trichoderma harzianum, Trichoderma lixii, Trichoderma polysporum, Penicillium glandicola, Penicillium swiecickii, species of the genera Rhizophydium, Fusarium, Daldinia Mortierella, Coniochaeta, Cystobasidium, Mrakia, Rhodothorula, Solicoccozyma and a number of others. A collection of fungal strains isolated from the bottom soils of Lake Baikal has been created.

The number of colony-forming units (CFUs), taxonomic structure, and species richness of fungal communities in bottom sediments of Lake Baikal at a depth from 9 to 178 m have been determined based on the culture method and high-performance sequencing of the ITS2 region of rDNA. We have identified 215 species of 138 genera, 50 orders, and 22 classes assigned to 6 phyla: Ascomycota, Basidiomycota, Mucoromycota, Mortierellomycota, Chytridiomycota, and Glomeromycota. Representatives of the phyla Chytridiomycota, Glomeromycota, and Rozellomycota are detected only by DNA barcoding. The cultural method and high-performance sequencing of the ITS2 region of rDNA enable us to reveal 77 and 146 species, respectively, and only 8 species are identified by both approaches. Most of the nucleotide sequences are not identified to the level of families and species. There are representatives of various ecological and trophic groups—saprotrophs, pathogens, and symbiotrophs—in the mycobiota of bottom sediments. These are mainly psychrotolerant organisms, and there are facultative anaerobic species among them. Changes in the taxonomic structure of fungal communities, depending on the depth, and species able to function in soils are revealed. These are, in particular, Pseudeurotium bakeri, Pseudeurotium hygrophilum, Pseudogymnoascus pannorum, Pseudogymnoascus roseus, Trichoderma hamatum, Trichoderma harzianum, Trichoderma lixii, Trichoderma polysporum, Penicillium glandicola, and Penicillium swiecickii; species of the genera Rhysophydium, Fusarium, Daldinia Mortierella, Coniochaeta, Cystobasidium, Mrakia, Rhodothorula, and Solicoccozyma; and a number of others. A collection of fungal strains isolated from bottom sediments of Lake Baikal has been created.

Изменения таксономической структуры грибного сообщества при переработке коровьего навоза с соломой с помощью червей Eisenia fetida изучены с применением принципиально разных методов - культурального и метабаркодинга (путем амплификации и высокопроизводительного секвенирования ITS2 рДНК). С помощью метабаркодинга в субстратах и вермикомпосте идентифицировано значительно больше таксонов грибов, чем методом посева (66 и 33 вида соответственно). Единичные виды были установлены одновременно обоими методами. Методом метабаркодинга выявлены операционные таксономические единицы в Ascomycota, Basidiomycota, Mortierellomycota, Chytridiomycota, Glomeromycota, Basidiobolomycota, Rozellomycota, Aphelidiomycota, культуральным методом - грибы из Ascomycota, Basidiomycota, Mucoromycota. Видовое богатство сообщества снижалось в первые 10-20 сут переработки субстратов, затем росло и достигало максимальных значений в вермикомпосте (60 сут). Оба метода показали доминирование аскомицетов на всех этапах переработки субстрата E. fetida. Метабаркодинг показал доминирование сордариомицетов порядка Sordariales (48-53 %), преимущественно Zopfiella spp., и представленность на уровне нескольких процентов грибов порядков Pezizales, Microascales, Hypocreales, Pleosporales, Chaetothyriales, Onygenales, Eurotiales. При вермикомпостировании наблюдали увеличение доли в сообществе Chytridiomycota (с 1,1 до 3,2 %). Одновременно снижалась доля грибов отделов Mortierellomycota(с 5,7 до 1,5 %) рода Mortierellaи Basidiomycota (с 8 и 21 до 3 %) при росте их разнообразия. Среди базидиомицетов преобладали Coprinellus marculentus, Coprinellus subdisseminatus, Coprinus annuloporus, Occultifur sp. Согласно посевам при переработке отходов и в вермикомпосте также преобладали аскомицеты, но других видов - Diplodascus geotrichum, родов Penicillium, Aspergillus, Talaromyces, Trichoderma, Fusarium, мукоромицеты рода Mucor и базидиомицеты Filobasidium wieringae. Выявлены грибы, способные к разложению различных полимерных соединений в отходах, активные деструкторы лигноцеллюлозы. Обнаружены копрофилы, кератинофилы, термофильные и термотолерантные виды, представители родов Trichoderma, Penicillium, способные обусловливать супрессивные свойства вермикомпоста к фитопатогенам и патогенам человека. Рассмотрены различия в микобиоте при компостировании и вермикомпостировании различных отходов. Changes in the taxonomic structure of the fungal community during the processing of cow manure with straw using Eisenia fetida worms were studied using fundamentally different methods - cultural and metabarkoding (by amplification and high-performance sequencing of ITS2 rDNA). Significantly more fungal taxa have been identified in substrates and vermicompost by application of metabarkoding than by plating method (66 and 33 species, respectively). Single species were identified simultaneously by both methods. The method of metabarcoding revealed OTE of Ascomycota, Basidiomycota, Mortierellomycota, Chytridiomycota, Glomeromycota, Basidiobolomycota, Rozellomycota, Aphelidiomycota, fungi from Ascomycota, Basidiomycota, Mucoromycota were isolated by culture method. The species richness of the community decreased during the first 10-20 days of substrate processing, then grew and reached maximum values in the vermicompost (60 days). Both methods showed the dominance of ascomycetes at all stages of transformation of sunstrates by E. fetida. Metabarcoding showed the dominance of sordariomycetes of the order Sordariales (48-53 %), mainly Zopfiella spp., fungi of the orders Pezizales, Microascales, Hypocreales, Pleosporales, Chaetothyriales, Onygenales, Eurotiales had the representation at the level of several percents. The increase of the portion of Chytridiomycota in the community (from 1,1 to 3.2 %) was observed during vermicomposting. At the same time, the representation of fungi of Mortierellomycota (5.7 to 1,5 %) of genus Mortierella and Basidiomycota (from 8 and 21 to 3 %) decreased with an increase in their diversity. Among the basidiomycetes, Coprinellus marculentus, Coprinellus subdisseminatus, Coprinus annuloporus, Occultifur sp prevailed. According to the plating method, ascomycetes also prevailed during waste processing and in the vermicompost, but it were other species - Diplodascus geotrichum, genera Penicillium, Aspergillus, Talaromyces, Trichoderma, Fusarium, mucoromycetes of the genus Mucor and basidiomycetes - Filobasidium wieringae. Fungi capable of decomposition of various polymer compounds in waste, active destructors of lignocellulose have been identified. Coprophiles, keratinophiles, thermophilic and thermotolerant species, representatives of the genera Trichoderma, Penicillium, capable of determining the suppressive properties of vermicompost to phytopathogens and human pathogens were found. The differences in mycobiota during composting and vermicomposting of various wastes are considered.

The activity of CO2 efflux, N2 fixation, and denitrification, as well as the physiological state of the community of microorganisms-destructors were assessed depending on the decay stage of the coarse woody debris (CWD) in the incubation experiments with the coarse woody debris of Norway spruce (Picea abies L.) and podzolic soil (Retisol). The coarse woody debris and soil were sampled at the experimental sites of the Central Forest State Reserve (Tver Region, Russia). Maximal CO2 emissions caused by CWD decomposition was associated with the decay stages III and IV. Also, the latter two showed maximal values of such sound indices of microbial activity as substrate induced respiration (SIR, 50 μg С–СО2/(g h)), percentage of easily decomposable С in organic matter (А1, 66%) and metabolic quotient qCO2 (0.78). Unlike the СО2 emission, maximal activity of N2 fixation was at the earlier decay stage II. The values of N2 fixation and denitrification activities indicate a gradual and complicatedly regulated transition process from the properties of bacterial and fungal communities of CDW to those in the soil during stages II, III and IV. The dramatic, more than 3-fold decrease was found only for C : N in CWD during the stages III–IV transition. СО2 emission at the stage V increased dramatically. Nevertheless, the CWD organic matter even at this latest decay stage had lower sustainability than organic matter of podzolic soil.

The aim of the present work was to explore insights into the possibility of cultivating the mycelium of the edible basidiomycetes, i.e., Agaricus bisporus (J.E. Lange) Imbach, Lentinula edodes (Berk.) Pegler, and Pleurotus ostreatus (Jacq.) P. Kumm. on wastes produced from lavender, sage, mint, and rose. To achieve this goal, we assessed the growth and development of strains on various substrates, a component analysis of the biomass of strains, initial essential oil raw materials after processing, and raw materials after exposure to the mycelium of basidial fungi strains. The wastes of essential oil production can be transformed with the help of edible basidiomycetes (A. bisporus, L. edodes, P. ostreatus) into a valuable fodder product enriched with proteins and vitamins and with good organoleptic properties. The best of the tested substrates was the green mass of mint after successive distillation and extraction. The conversion of solid waste from lavender, rose, sage, and mint processing depends on the types of strains. The high accumulation of octen-3-ol (up to 1.38 g/kg of the substrate) by P. ostreatus was confirmed by its organoleptic evaluation. The results suggested the cultivation of edible mushroom mycelium on the solid waste of mint, lavender, and sage processing could produce high-grade (enriched in proteins and vitamins) biomass for the purpose of fodder. These by-products could serve as a basis for the creation of cultivation technology for champignon, shiitake, and oyster mushrooms as food products using secondary resources of essential oil production.

The activity of CO2 efflux, N2 fixation, and denitrification, as well as the physiological state of the community of microorganisms-destructors were assessed depending on the decay stage of the coarse woody debris (CWD) in the incubation experiments with the coarse woody debris of Norway spruce (Picea abies L.) and podzolic soil (Retisol). The coarse woody debris and soil were sampled at the experimental sites of the Central Forest State Reserve (Tver Region, Russia). Maximal CO2 emissions caused by CWD decomposition was associated with the decay stages III and IV. Also, the latter two showed maximal values of such sound indices of microbial activity as substrate induced respiration (SIR, 50 μg С–СО2/(g h)), percentage of easily decomposable С in organic matter (А1, 66%) and metabolic quotient qCO2 (0.78). Unlike the СО2 emission, maximal activity of N2 fixation was at the earlier decay stage II. The values of N2 fixation and denitrification activities indicate a gradual and complicatedly regulated transition process from the properties of bacterial and fungal communities of CDW to those in the soil during stages II, III and IV. The dramatic, more than 3-fold decrease was found only for C : N in CWD during the stages III–IV transition. СО2 emission at the stage V increased dramatically. Nevertheless, the CWD organic matter even at this latest decay stage had lower sustainability than organic matter of podzolic soil.

The class Archaeorhizomycetes (Taphrinomycotina, Ascomycota) is a cosmopolitan group of fungi associated with the plant root system. Representatives of this class are extremely poorly studied due to the difficulty of cultivation, but sequences belonging to Archaeorhizomycetes are often detected during sequencing of natural substrates. Four unique sequences belonging to Archaeorhizomycetes were obtained during a study of the diversity of fungi associated with the orchid Goodyera repens by next-generation high-throughput sequencing of the ITS2 site. One sequence identical to Archaeorhizomyces borealis was identified in Russia for the first time, while two sequences presumably belong to a yet undescribed genus. One sequence belonging to an undescribed species of the genus Archaeorhizomyces is the most frequently detected in all types of samples (sod-podzolic soil, coniferous tree roots, rhizosphere, and orchid roots). The presence of nucleotide sequences of representatives of this class in the root system of Goodyera repens was shown for the first time, and the presence of one sequence in free soil was shown for the first time. The sequences were deposited in the GenBank database.

Aqueous suspensions (colloids) containing detonation nano-diamond (DND) feature in most applications of DND and are an indispensable stage of its production; therefore, the interaction of DND with water is actively studied. However, insufficient attention has been paid to the unique physico-chemical and biological properties of transparent colloids with low DND content (≤0.1%), which are the subject of this review. Thus, such colloids possess giant dielectric permittivity which shows peculiar temperature dependence, as well as quasi-periodic fluctuations during slow evaporation or dilution. In these colloids, DND interacts with water and air to form cottonwool-like fibers comprising living micro-organisms (fungi and bacteria) and DND particles, with elevated nitrogen content due to fixation of atmospheric N2. Prolonged contact between these solutions and air lead to the formation of ammonium nitrate, sometimes forming macroscopic crystals. The latter was also formed during prolonged oxidation of fungi in aqueous DND colloids. The possible mechanism of N2 fixation is discussed, which can be attributable to the high reactivity of DND.

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.

The activities of CO2 emission, N2 fixation, and denitrification, as well as the physiological state of the community of microbial decomposers are assessed at different stages of decay of coarse woody debris (CWD) in the incubation experiments with the Norway spruce (Picea abies L.) and the humus horizon of podzolic soil (Retisol). The CWD of five decomposition stages and soil are sampled at the experimental plots of the Central Forest State Reserve (Tver oblast, Russia). The maximum CO2 emissions are associated with CWD decay stages III and IV. In addition, characteristic of these stages are the maximum values of the important indices of CWD and soil microbial activity, such as the substrate-induced respiration (SIR, 50 µg C–CO2/(g h), share of easily decomposable С in organic matter (A1, 66

The class Archaeorhizomycetes (Taphrinomycotina, Ascomycota) is a cosmopolitan group of fungi associated with the plant root system. Representatives of this class are extremely poorly studied due to the difficulty of cultivation, but sequences belonging to Archaeorhizomycetes are often detected during sequencing of natural substrates. Four unique sequences belonging to Archaeorhizomycetes were obtained during a study of the diversity of fungi associated with the orchid Goodyera repens by next-generation high-throughput sequencing of the ITS2 site. One sequence identical to Archaeorhizomyces borealis was identified in Russia for the first time, while two sequences presumably belong to a yet undescribed genus. One sequence belonging to an undescribed species of the genus Archaeorhizomyces is the most frequently detected in all types of samples (sod-podzolic soil, coniferous tree roots, rhizosphere, and orchid roots). The presence of nucleotide sequences of representatives of this class in the root system of Goodyera repens was shown for the first time, and the presence of one sequence in free soil was shown for the first time. The sequences were deposited in the GenBank database.