Articles

The aim of this study was to investigate the patterns of plant diversity formation on extensive green roofs in a continental climate and the role of adjacent lawns as sources of colonizing species. In 2024, extensive green roofs were established in Moscow and Yekaterinburg on two substrate types (regional and universal) at two depths (15 and 25 cm), with 3 replicates per treatment. In May 2025, regional plant species (seedlings) were planted: in Moscow —Festuca glauca Vill., Thymus serpyllum L., Achillea millefolium L.; in Yekaterinburg —Aster alpinus L., Festuca glauca Vill., Festuca rubra L., Origanum vulgareL., Dianthus acicularisFisch. ex Ledeb., Veronica spicata L. Weeds were not removed. In September 2025, species were recorded, and community similarity (Jaccard coefficient, Bray – Curtis index) was measured between lawns and roofs, as well as within roofs between different treatments, together with alpha diversity (Shannon index H', Simpson index 1-D, and evenness). In parallel, the species composition of adjacent lawns was surveyed. In total, 50–60% of roof species were also present on lawns; the Jaccard coefficient ranged from 0.14 to 0.32; H' for roofs ranged from 1.08 to 2.08 (13–15 species). Unique species of Moscow roofs were dominated by R/CR strategies (Lactuca saligna L., Lactuca serriola L., Amaranthus retroflexus L., Portulaca oleracea L., Digitariasanguinalis(L.) Scop., Gnaphalium uliginosum L., Iva xanthiifolia Nutt., Acalypha australis L., Euphorbia virgataWaldst. & Kit., Lipandrapolysperma(L.) S. Fuentes, Uotila & Borsch, Epilobium obscurumSchreb., Myosotis sparsifloraJ.C.Mikan ex Pohl, Veronica longifolia L., Festuca arundinaceaSchreb.), whereas in Yekaterinburg C/CR species dominated (Trifolium arvense L., Medicago falcata L., Lolium perenne L., Rumex obtusifolius L., Viola tricolor L., Galiumspurium L., Arenaria serpyllifolia L., Setariaviridis(L.) P.Beauv., Rudbeckia hirta L.). High spatial heterogeneity in similarity and diversity indices was observed for Moscow roofs, whereas substrate type and depth had no significant effect. Thus, lawns were the main source of spontaneous colonizers of green roofs. Vegetation succession during the first year on green roofs went through an R/CR stage, probably under the dominant influence of climatic factors.

Abstract.This study presents the findings of an investigation into the abundance and morphological diversity of bacteriophages in samples of urban soils (Urbanozem and Replantozem) and atmospheric dustfall (ADF) collected across Moscow from sites with varying degrees of anthropogenic impact. Using direct epifluorescence microscopy with the SYBR Gold stain, it was demonstrated that bacteriophage abundance (virus-like particles, VLPs) was higher in soils (1.12–2.1010⁹ VLPg‒1) than in ADF (0.42–0.6410⁹ VLPg‒1), correlating with total bacterial counts. Through enrichment culture techniques followed by biological purification, a collection of bacteriophages (coliphages) infecting Escherichia coli strains with different cell surface compositions (different O-antigen types) was obtained. Transmission electron microscopy revealed that some of the isolated coliphages belong to the class Caudoviricetes (tailed phages) and are characterized by Siphoviridae (possessing long, non-contractile tails) and Podoviridae (possessing short tails) morphotypes. The obtained data underscore the significant role of bacteriophages in the functioning of microbial communities within urban ecosystems and their potential for use in the bioremediation of urban soils.

For the first time, a comprehensive study of the biological activity of microbial communities in protected tropical ecosystems of Vietnam has been conducted using the example of four types of substrates: mineral soils and associated plant litter, rhizospheric soil, and specific soil-like formations —“suspended” soils in baskets of epiphytic ferns. It is shown that suspended soils and plant litter are characterized by 3‒5 times higher microbial biomass (up to 1.44 mg•g⁻1), as well as significantly more intensive processes of carbon dioxide emission, nitrogen fixation and denitrification compared with mineral soil horizons. The revealed high biological activity of these substrates correlates with an extremely high content of organic carbon (up to 51.4%) and less acidic pH values. For the first time, methane emissions were quantified for this territory, showing maximum values in the upper soil layer (up to 173 ng CH4•g‒1•day–1) and a negative correlation with altitude (p=0.0001). The data obtained make it possible to identify plant litter and epiphytic “suspended” soils as key loci of biogeochemical cycles of nitrogen and carbon in the tropical forests of Vietnam.

Actinomycetes are key functional group of soil microorganisms that play a critical role in organic matter decomposition and the regulation of biogeochemical cycles in tropical ecosystems. This study provides a comprehensive analysis of actinomycete community structure and the physiological traits of cultivable strains in soils and litter from two protected areas in Southern Vietnam: Bidoup and Cat Tien Nature Reserves. We combined culture-based and molecular approaches, including quantification of cultivable actinomycetes, assessment of strain tolerance to abiotic stresses, evaluation of enzymatic activities, and high-throughput 16S rRNA gene sequencing to determine the taxonomic composition of prokaryotic communities. Actinobacteria were found to be dominant across soils, with clear differences between soils and litter. Litter communities were relatively uniform across elevations, whereas soil communities displayed pronounced variation. Cultured Streptomyces strains exhibited broad stress tolerance and high enzymatic activity, underscoring their ecological significance in tropical soil functioning.

A comprehensive study of prokaryotic communities (microbiomes) of bacterial mats and snottites from the karst cave Sheki-Kh’ekh was carried out for the first time, with comparison to cave soil-like bodies (SLBs) from the Muhammed-Kh’ekh cave and adjacent brown forest soil. The total abundance of bacterial cells in mats and snottites varied within a relatively narrow range, from 0.26 to 0.35 billion cells per mL, reaching maximum values in floating bacterial mats and minimum values in snottites. In soil-like bodies, the total bacterial abundance was 0.28 billion cells per g. Actinomycete mycelium was detected in all cave samples, with the highest values observed in floating bacterial mats and the lowest in shoreline bacterial mats.
Metabarcoding analysis (16S rRNA gene sequencing) revealed high taxonomic diversity of prokaryotic communities across the studied substrates. The greatest diversity was recorded in floating bacterial mats (25 phyla and 74 genera). In all cave substrates, the dominant phyla were Pseudomonadota and Bacillota, while Bacteroidota also dominated in floating bacterial mats. Lower relative abundances were observed for Actinomycetota, Verrucomicrobiota, Chloroflexota, Chlorobiota, and Thermodesulfobacteriota. Eleven bacterial phyla were shared between soil and floating bacterial mats: Pseudomonadota,Bacillota,Bacteroidota,Verrucomicrobiota,Chlorobiota,Chloroflexota,Actinomycetota,Acidobacteriota,Cyanobacteriota,Planctomycetota, and Armatimonadota, along with two candidate phyla, Sumerlaeota and Hydrogenedentes. Two archaeal phyla, Woesearchaeota and Nanoarchaeota, were detected in bacterial mats.
A total of 191 bacterial genera were identified across all studied substrates. Only 12 genera were common to bacterial mats and soil: Brevundimonas,Devosia, Flavobacterium,Luteolibacter, Paenibacillus,Paenisporosarcina,Pseudarthrobacter, Pseudomonas,Rhodanobacter,Sphingomonas, Sumerlaea, and Thermomonas. A distinctive feature of floating bacterial mat communities was the high representation of genera involved in sulfur cycling processes. Functional profiling revealed the predominance of sulfur- and iron-cycle-related functions in bacterial mats, whereas nitrogen-cycle-related functions and chemoheterotrophy prevailed in soil communities.
This study significantly expands current knowledge of the taxonomic composition of prokaryotic communities inhabiting bacterial mats and snottites of sulfidic caves in the Chechen Republic. The presence of bacterial genera involved in sulfur and iron transformation processes highlights their ecological significance. The results obtained on the diversity of prokaryotic communities in mats, snottites, and soil-like bodies are of interest for understanding ecosystem functioning and for the targeted search of strains with valuable biotechnological properties.

The article presents the results of the research of the prokaryotic complex associated with plants in blackalder-meadowsweeteutrophic swamp (Zapadnodvinskiy District, Tver Region). The phylloplane (leaves, stems), rhizoplane (roots), and rhizosphere soil of six plants, namely Calla palūstris L., Filipendula ulmaria (L.) Maxim., Carex cespitosa L., Urtica dioica L., Athyrium filix-femina (L.) Roth ex Mert.and Scirpus sylvaticus L., were analyzed. The abundance of unicellular and mycelial bacteria in plant and soil substrates was determined by luminescent microscopy and culture method. The taxonomic composition of cultured bacteria was assessed on the basis of phenotypic characteristics and the results of 16S rRNA nucleotide sequence analysis. It was found that the dimensionless universal characteristic of prokaryotic communities — the K index (the ratio of bacteria counts based on microscopy and culture data) —and the alpha diversity index (the Shannon index)— increase in the order phylloplan<rhizoplan< rhizosphere soil. Representatives of 4 phyla, 23 genera, and 63 species of cultivated bacteria, 27 of which are mycelial. were isolated and diagnosed from the analyzed substrates. It was determined that Carexmicroloci were characterized by maximum abundance and diversity of bacteria. Filipendulamicroloci are promising targets for the isolation of streptomycetes with antagonistic potential against phytopathogenic fungi that cause various diseases in agricultural plants. It was shown that rhizosphere soil under plants in blackalder-meadowsweeteutrophic swamps is a substrate for the isolation of bacteria of the genus Stenotrophomonas, which are used as effective bioinoculants to stimulate plant growth and as microbiological agents for biocontrol.

A comprehensive study of the mycobiota in eutrophic peat soils under forests was conducted: birch forest, mixed forest (Tomsk District, Tomsk Region), black alder forest, and pine forest (Zapadnodvinsky District, Tver Region). The litter (layers L and F) and eutrophic peat horizon (TE: 0–20, 20–30, and 30–50 cm) were analyzed during the summer and autumn of 2021. The stocks and structure of fungal biomass were studied using luminescent microscopy, and the number of cultivated representatives was determined using the sowing method. Fungi were identified on the basis of phenotypical characteristics and the results of 26S rRNA nucleotide sequence sequencing. It was found that in the litter of the studied soils, fungal biomass ranged from 2 to 30 mg∙g‒1, fungal biomass stocks ranged from 28 to 189 g∙m–2, and fungal biomass carbon stocks ranged from 139 to 945 kgC∙ha‒1. In the eutrophic peat horizon, they ranged from 0,4 to 19,4 mg∙g–1, from 52 to 622 g∙m–2, and from 262 to 3110 kgC∙ha‒1, respectively. All indicators of fungal abundance increased from summer to autumn. The contribution of litter to fungal biomass reserves was more significant in soils under deciduous forests — up to 67%, while in soils under coniferous forests it did not exceed 10%. Fungal biomass in the studied horizons was mainly represented by mycelium, with spores accounting for 1 to 40%.The number of cultivated fungi in the studied soils ranged from 103 to 106 CFUg‒1 and was 2–3 orders of magnitude higher in litter than in TE. Seasonal changes in the number of micromycetes were detected mainly in litter (summer values exceeded autumn values by 1–2 orders of magnitude). Over two seasons, 85 species of micromycetes from 46 genera, 27 families, 15 orders, 7 classes, and 2 divisions (Mucoromycota and Ascomycota) were isolated from the studied soils.Representatives of the Ascomycota division predominated, accounting for 89% of the total species composition. In soil microfungal communities, fungi of the Penicillium and/or Trichoderma genera dominated or were frequently encountered, but the vast majority of representatives of other genera were characterized as rare and incidental. In litter, the Shannon index ranged from 0,78 to 2,32, and in TE from 0,31 to 2,55. In autumn,as rule, a decrease was observed in almost all soil horizons.The species similarity of the communities of cultivated fungi (Ks) of the studied soils varied in the range of 0.42–0.56, and between horizons reaches 0.70.

The wide species diversity of chitinolytic actinomycetes producing secondary metabolites and hydrolytic enzymes offers opportunities for effective soil biocontrol aimed at protecting plants from phytopathogens and preserving soil biodiversity. This study examined the chitinolytic potential of five soil actinomycete strains from the genus Streptomyces(S. flavovirens TT, S. sindenensis TK, S. baarnensis assi-23TB, S. anulatus TG, and S. xiamenensis TB) through integrated analytical and molecular biological approaches.The study demonstrated that the fundamental mechanism of Streptomycesstrain adaptation to chitin utilization is the targeted induction of functional chitinase genes.We identified distinct genome activation strategies and observed that high genetic activity leads to a robust physiological response, including active biomass accumulation and CO₂ emission. These findings confirm the high competitiveness of the investigated strains under conditions of limited access to readily available carbon and nitrogen sources. The study elucidated the interaction of the target strain Streptomyces baarnensis assi-23TB (VKPM Ac-2228) with two specific phytopathogens in both in vitro and in planta systems, using wheat seedlings (Triticum aestivum L. cv. Arkhat) and microclonal potato plants (Solanum tuberosum L. cv. Romano) as host models. A comparative analysis was performed to correlate the metabolic capabilities of S. baarnensis assi-23TB, as theoretically predicted by bioinformatic tools (antiSMASH, PATRIC), with its actual phenotypic metabolite production. The strain exhibited significant chitinolytic activity. Our analysis revealed dibutyl phthalate (DBP) to be a constitutive secondary metabolite responsible for the baseline antimicrobial activity.Notably, several predicted biosynthetic gene clusters (10-epi-HSAF, keivymicin, alkylresorcinol, desferrioxamine B, naringenin, and zeatin) remained in a "silent" state under the experimental conditions. We found that the S. baarnensis exometabolome strictly depends on the presence of the host plant and specific pathogens (Fusarium graminearum and Phytophthora infestans). The association with wheat exclusively triggers the synthesis of the phytostimulant putrescine and energy metabolism regulators, such as lactic and succinic acids. This symbiotic system also drives the production of amino acids, sugars, and myo-inositol.The study experimentally confirms the multifunctionality of the Streptomyces baarnensis assi-23TB strain, which integrates direct enzymatic lysis of pathogens with the biochemical stimulation of plant growth and adaptive responses