The effect of 24-epibrassinolide on salicylic acid and methyl jasmonate on the health of microclonally propagated potato plants to the Y virus, their physiological state, and the functions of the pro-/antioxidant system was studied. A synergistic interaction of immunostimulants with methyl jasmonate or salicylic acid with methyl jasmonate and salicylic acid in mixtures against viral infection was revealed, which includes a decrease in the incidence of potato Y virus, activation of plant growth and a low level of detection of pro- and antioxidant reactions that cause the development of oxidative epidemic stress. The revealed positive effects between brassinosteroids and methyl jasmonate in the suppression of viral infection and activation of growth processes are manifested by their interchangeable contribution to the regulation of the balance between plant growth and immunity.

An expression vector containing the gene encoding the most common isoform Bet v 1.0101 of the Bet v 1 protein, the major birch pollen allergen, was created for a subsequent expression in the prokaryotic system of Escherichia coli. Total RNA from birch pollen collected in Belarus was used as a matrix. The expression vector pJC40-Веt v 1 was obtained using molecular-genetic methods: cloning, ligation, transformation. The specificity of the cloned fragment was confirmed by sequencing. During the study, 14 rare Escherichia coli codons were identified in the coding part of the cloned gene. The triplets were evenly arranged in the nucleotide sequence; codon clustering was observed only in two cases. The total percentage of rare triplets (8.75 %) and the calculated value of the codon adaptation level (0.57) allow us to predict a sufficiently efficient expression of the studied gene. The data obtained will be used in the synthesis of the recombinant polypeptide Bet v 1.0101.

The survival of fungi in Antarctica is a consequence of both ecological selection and evolutionary adaptation expressed at the physiological, metabolic, structural, and genetic levels. The study of the biological diversity of Antarctic micromycetes will help us to better understand the pathways of fungal dispersal in the biosphere, as well as to broaden our understanding of their role in extreme ecosystems. In addition, micromycetes of extreme habitats are the promising objects of biotechnology.

The purpose of the work is to study the biological diversity of microscopic fungi on natural and anthropogenically introduced substrates in the East Antartica research areas of Progress, Novolazarevskaya, and Mount Vechernyaya stations.

Traditional isolation methods were used to isolate micromycetes in culture. To determine the species composition, microbiological and molecular genetic methods were used. As a result of mycological analysis, 46 species of micromycetes from 22 genera and 3 phylum were identified. The taxonomic analysis was made and the dominant genera of micromycetes were identified: Thelebolus, Penicillium, Acremonium, Aspergillus, Cladosporium, Geomyces, Cadophora, Rhodotorula, Cryptococcus. The temperature-dependent growth features of micromycetes were analyzed: most of the isolated species were psychrotrophic. The greatest species diversity of micromycetes was noted in soils with plant and animal inclusions, the smallest – on stony substrates.

The Belovezhskaya Pushcha National Park is a unique natural monument that is the only relic flat forest in Europe. This is one of the oldest protected areas, in most of which old coniferous-broad-leaved forests are growing. They are of particular value for study and conservation of biological diversity.

The article presents the study results of the species diversity of fungi based on herbarium specimens stored in the MSK-F herbarium and the materials of our own collections in different-type phytocenoses on the territory of the Nikorsky forestry. Species identification of agaricoid basidiomycetes was carried out by standard mycological methods. As a result, 145 species were identified, including 8 varieties and 2 forms of basidial macromycetes. Of these, 34 species, including 2 varieties of agaricoid fungi, are rare for the mycobiota of the National Park, and 13 are very rare and are represented by single finds. The taxonomic analysis of the herbarium material and the published data showed that the dominant genera in terms of a number of species in the mycobiota of agaricoid basidiomycetes were represented by the genera Cortinarius (17 species), Lactarius (12 species), Mycena (10 species), and Russula (8 species).

The most representative in terms of the number of species of agaricoid fungi were coniferous phytocenoses, mainly pine forests, in particular blueberry-mossy pine forest.

The conducted ecological and trophic analysis revealed that the largest number of macromycete species belong to mycorrhiza-formers (35.19 %), the main part enters into the symbiosis with the roots of Pinus sylvestris and Quercus robur. 

We studied the seasonal changes in the taxonomic composition and abundance of phytoplankton in the littoral and pelagial zones of Obsterno Lake. A number of important differences recorded for the littoral and pelagic zones. The abundance in the littoral zone is higher in April, August and December. In other months it is higher in the pelagic zone. In the same months, the species richness in the littoral zone is also higher. These differences were influenced by such factors as biogenic elements (nitrogen and phosphorus), as well as the temperature factor. 

Pre-larvae hatching fecundity and ovarian fecundity of narrow-clawed crayfish populations were estimated in the lakes and reservoirs of Belarus. Statistically significant differences in the fecundity of females from various water bodies were noted only for Lake Kichino. For all other water bodies, the fecundity dependence on the length of females did not differ statistically and was described by one equation. The greatest loss of eggs was noted during the spawning period (oviposition), insemination and attachment to pleopods of the female. During this short period (2–3 hours), egg mortality of females 120 mm TL is 30 %, it decreases for small females and increases for large ones. During the gestation period, egg mortality averages 8 %. 

A whole genome sequencing of natural and mutant producer strains is the best way to analyze the genome and to search for mutations that could cause the acquisition of a number of properties valuable for biotechnological and pharmaceutical industry.

The main goal of current research was to identify mutations that had been induced by chemical mutagenesis in the genome of the mutant strain Рseudomonas chlororaphis subsp. aurantiaca B-162/15 resistant to hydrogen peroxide. It would give an opportunity to discover new genes potentially participating in phenazine compounds biosynthesis. Such an approach also makes it possible to identify genes, whose products do not directly participate in the phenazine synthesis, but influence the phenazine detoxification, excretion, and optimization of antioxidant system activity. Most of all, it could help us to discover new unpredicted enzyme systems that might be involved into this process.

The genome size of P. chlororaphis subsp. aurantiaca B-162/15 was 7109863 b. p. It contained 6493 open reading frames and 66 sequences encoding transport and ribosomal RNA. Comparison of a wild-type strain and B-162/15 mutant genomes revealed 16 mutations, 13 of which were located in coding sequences and 3 were located in intergenic regions. Six mutations led to radical replacements in amino acid sequences of coded proteins (with a Grantham distance of more than 80). We managed to identify four potential gene-candidates, which could influence the phenazine metabolism and provided the ability of mutant strain to superproductivity. They were arginine N-succinyltransferase, phosphoenolpyruvate synthase, iron-contain-ing redox enzyme family protein, membrane-associated proteins in eicosanoid and glutathione metabolism. Three prophage regions were identified, two regions of which were intact and one region was incomplete. The prophage genes, as well as the bacterial genes were inside these regions. We also managed to identify two genes of Agrobacterium tumefaciens inside prophage region 2. It was possible that these regions were introduced into the genome of studied strain by viral transduction. 

For the first time the data have been presented on the chemical composition of the essential oil of Monarda fistulosa L., cultivated in the north-east of Belarus (Vitebsk region). Dried leaves and inflorescences of M. fistulosa L., harvested in the flowering phase, were used to obtain the essential oil. More than 70 components were detected by chromato-mass spectrometry, of which 33 were identified. The main components of the essential oil are thymol (29.18 % in leaves and 38.4 % in inflorescences), carvacrol (22.83 % in leaves and 21.5 % in inflorescences) and p-cymene (17.5 % in leaves and 9.5 % in inflorescences). The main component of essential oils is thymol, which makes it possible to attribute the studied samples of M. fistulosa L. to the thymol chemotype. M. fistulosa L. can be recommended for further study and cultivation as a promising essential oil plant in the north-east of Belarus. 

The taxonomic structure of the macrozoobenthos of 11 springs of the Grodno region has been established. There were identified 53 lower definable taxon (LDT) belonging to 4 types of aquatic invertebrates: Platyhelminthes – 1 LDT, Mollusca – 10, Annelida – 5, Arthropoda – 37 LDT. Among the identified animals, 23 species were first noted for the springs of the Grodno region. The fauna of the studied aquatic invertebrates of the springs of the Grodno region represented by rare and protected species of animals not only in Belarus, but also in Europe. Springs are a special type of natural reservoirs, which are inhabited by a specific fauna – one of the important components of the overall biological diversity of water bodies in Belarus. The most species of the fauna of the studied springs is formed by species exhibiting cryophilic properties, some of these animals are obvious relics of the Ice Age. The ways of penetration of these species into the modern fauna of Belarus are also not yet fully understood.