Plants of the Miscanthus genus (Miscanthus Anderss.) have a unique index of biomass production in relation to the occupied area. Miscanthus plants can be attributed to promising second-generation raw materials for the production of bioethanol and biofuel. Miscanthus plants are characterized by a high cellulose content. Herein, we report the results of a study on the obtained delignified cellulose with subsequent processing into bioethanol using microbial communities. In the course of the study, the optimal conditions for the delignification of the initial plant material for cellulose were selected. Ethanol with a high degree of conversion was successfully obtained from the isolated delignified cellulose. The article describes the pilot technological scheme for the conversion of Miscanthus plant biomass to bioethanol involving the delignification stages, followed by the conversion of the resulting cellulose into bioethanol by a consortium of microorganisms. As a result of the study, it was found that delignification using trifluoroacetic acid leads to the production of cellulose of high purity. Bioethanol with a yield of 3.1% to 3.4% in terms of the initial amount of biomass was successfully obtained by a microorganism consortium of Saccharomyces cerevisiae M Y-4242/Pachysolen tannophilus Y-3269, and Scheffersomyces stipitis Y-3264.

Recently, a question of producing a complex of biologically active substances from microalgae has aroused widespread interest. It is known that microalgae are able to produce a significant amount of exopolysaccharides. The aim of this work was to study morphological features and growth parameters of psychrophilic microalgae and cyanobacteria for the subsequent production of exopolysaccharides. The morphology of microalgae was observed using a binocular microscope. Growth parameters were studied by spectrophotometry; parameters of the culture medium were determined using a pH-meter. Exponential dependency graphs that show the dynamics and expected growth rate of microalgae were built. A rate of growth and polysaccharide biosynthesis in microalgae was determined upon changing the light intensity from 50 to130 mmol/m²/s. The highest level of cell counts in the logarithmic growth phase was up to 0.8 for Scenedesmus obtusiusculus Chod IPPAS S-329. A level of cells also varied in the deceleration phase from 0.25 for Ankistrodesmus acicularis Korsch IPPAS А-218 to 1.8 for Scenedesmus obtusiusculus Chod IPPAS S-329. Microalgae showed a high level of biomass accumulation under alkalophylic conditions. Eukaryotic algae actively photosynthesized at a pH of more than 8.0 and a temperature of 30 °C.The maximum activity at the level of pH 3.0/3.2 in the lag phase was 100% in C-1509 Nannochloris sp. Naumann. Microalga C-1509 Nannochloris sp. Naumann showed a high level of biomass accumulation under alkalophylic conditions; it photosynthesized at a pH of more than 8.0 and a temperature of 30 °C. It has been proved that neutrophiles can grow at pH lower than 3.0; this corresponds to the results of the experiments with the collection strains of microalgae with biomass productivity of 27.3%. At the alkaline pH values of 8.3-9.0, biomass productivity reduced from 46.0 to 37.2%. It is especially interesting that at the alkaline pH values of 7.5 and 8.0 biomass productivity of microalgae increased, which indicates the optimal growth conditions at this narrow pH range. An ability of microalgae to produce exopolysaccharides opens prospects of their use for practical purposes.

Food dyes are widely used in the food industry to improve the sensory properties and consumer attractiveness of finished products. However, synthetic dyes are associated with potential health risks. Microalgae are known to produce natural pigments that provide intense coloring and possess various biological metabolites, e.g., chlorophylls and carotenoids. This article reviews available data on the pigment composition of Scenedesmus microalgae, including cultivation strategies, efficient pigment biosynthesis, prospects for the functional food and nutraceutical industries, and commercial limitations. The review covered scientific publications on Scenedesmus colorants, their bioactive properties, and / or practical application registered in ScienceDirect (Scopus), Springer Link, MDPI, and Google Scholar in 2015–2025. Scenedesmus microalgae accumulate significant amounts of chlorophylls (≤ 30.8 mg/g) and carotenoids (≤ 98.0 mg/g). The carotenoid profile of Scenedesmus consists of a variety of compounds, with such commercially important substances as lutein (≤ 10.7 mg/g), β-carotene (≤ 19.0 mg/g), and astaxanthin (≤ 23.8 mg/g). Scenedesmus carotenoid extracts possess antimicrobial, antiproliferative, hypolipidemic, and antidiabetic properties. As a result, Scenedesmus pigments are promising components to be used in functional foods and nutraceuticals. Various cultivation strategies aim at increasing the pigment yield in Scenedesmus biomass. Two factors hinder the successful commercialization of Scenedesmus for pigment production: 1) pigment composition depends on the strain and cultivation conditions; 2) large-scale pigment cultivation and extraction are technically and economically complex. Further research is required to assess the safety and bioavailability of Scenedesmus pigments, as well as to improve industrial cultivation and extraction technologies.

The article presents the culturing of nine microalgae strains from the IPPAS collection of IFR RAS using components of the aqueous phase of the excessive activated sludge hydrothermal revitalization process as a substrate. In order to select the most promising cultures, their growth characteristics and efficient removal of NH₄⁺ ions, PO₄^3- and organic compounds were studied. All the studied cultures are shown to be able to utilize components of the aqueous phase as a nutrient substrate. The highest specific growth rate of 0.92 day^-1 was observed in the strain Chlorella sp. IPPAS C-1210. However, the Parachlorella kessleri IPPAS C-9 and Chlorella minutissima IPPAS C-123 strains were also promising in terms of their efficiency of pollutant removal from the medium: efficiency of ammonium nitrogen assimilation was 78 and 81%, while phosphate ion assimilation was 89 and 91%, respectively. The biomass composition of C-9 and C-123 cultures was investigated, mainly consisting of polysaccharides – at 41 and 44% – and proteins – at 31 and 25% of the total mass, respectively. A high degree of neutralization of the medium was additionally achieved as a result of consecutive two-stage purification of the aqueous phase of the process of hydrothermal revitalization of excessive activated sludge with the use of microorganisms-destructors (Paenarthrobacter nicotinovorans and Comamonas testosteroni) and the studied microalgae cultures. During 17 days of the purification process, the concentration of ammonium ions decreased from 289.8±14.9 to 51.1±2.2 mg/dm³, phosphates from 116.3±8.1 to 11.3 mg/dm³; the overall efficiency of the process of pollutants removal from the aqueous phase was up to 90%.

Eye movements are interconnected with the cognitive process, and therefore, the analysis of oculomotor activity seems to be a useful tool for studying the process of visual attention, working memory, and informational processing. In this study, the characteristics of the saccadic and fixative components of eye movements in preschool children (from 4 to 6 years old) with different perception of a static image were obtained. Four groups of children were identified on the basis of a qualitative answer to the question about what is shown in the picture (correct answer, wrong answer, no answer, correct answer after a prompt). The study groups were different by oculomotor activity. The results contribute to the understanding of different types of cognitive strategies. This can be useful for creating individual learning plans at school, forming an optimal cognitive strategy for analyzing the necessary information for a successful life.