The presence of autotrophs, heterotrophs and mixotrophs among euglenoid taxa, multiple means of nutrition, and high tolerance to a wide range of thermal living conditions contribute to their colonization of various types of water bodies in different climatic zones. The formation of water “blooms” by euglenoids occurs during accelerated development and intensive cell division of these organisms. Euglenoids outcompete other microalgae and produce significant biomass under favorable conditions. The ability to produce temporal, reproductive and protective cysts also contributes to rapid bloom formations. Our observations suggest that their features probably make them model organisms for observing environmental changes in small water bodies. So far, little attention has been given to the species-dependent color variation of euglenoid blooms. Long-time research on euglenoid taxonomy, biogeography and habitat observations allow observers to recognize different blooms depending on the species causing the phenomenon: Euglena sanguinea, E. mutabilis, E. clara, E. hemichromata, E. geniculata, E. agilis, Euglenaria anabaena, Euglenaformis chlorophoenica, Monomorphina pyrum, Phacus pleuronectes, Ph. orbicularis, Lepocinclis ovum, Trachelomonas volvocina, T. volvocinopsis and T. caudata. The color range of euglenoid blooms are presented here for the first time.

Forty years ago, the transformation of the estuary of the Black Sea to a freshwater reservoir was started by its connection with the Danube River through the Danube–Sasyk Canal. Today, the inflow of the Danube water into the Sasyk is the main component of the water balance, affecting the internal and external water exchange, and it is, in general, responsible for the quality of the aquatic environment. In addition, the channel is a migration route for hydrobionts and the main source of invasion. We describe the changes in the composition of algal communities in Sasyk, which was converted from an estuary to a reservoir during three stages: estuary-lake in 1967–1977 (stage I), the forming of the reservoir from 1980–1990 (stage II), and the reservoir from 2013–2019 (stage III). Average salinity decreased from 7790 to 491 mg L−1 chlorides, and the species richness of algae increased from 259 to 289 taxa during the Sasyk transformation. Analysis of the algal communities revealed that salinity could have an effect on their composition. The species list for the Sasyk, including 586 taxa of algae and cyanobacteria (613 infraspecific taxa), is presented here for the first time. Rare marine and freshwater taxa present in the algal community at the modern stage of the reservoir and their transformation are discussed. An ecological analysis of the different stages of the Sasyk transformation from an estuary into a reservoir was conducted. The increase in species richness for stages II and III along with an increase in desalination was noted. To keep the current ecological status of the reservoir and its hydrological stability, the role of the Danube River should be considered. Bioindicators, statistical analysis of species, and environmental variables’ relationships confirm salinity as a major regulating factor that can be observed by way of long-term monitoring.

Peculiarities of soil ecosystems (algae, microbiocenosis, agrochemical and agrophysical characteristics) of the Uholsko-Shirokoluzhanskyi beech relict forests of the Carpathian Biosphere Reserve, as well as artificial European beech (Fagus sylvatica L.) plantations located on the botanical and geographical plots "Ukrainian Carpathians" of the M.M. Gryshko National Botanical Garden of NAS of Ukraine. Soil samples were collected from May to September during 2020–2021. The species composition of soil microalgae, the number of ecological and trophic groups of microorganisms, agrophysical and agrochemical characteristics of soils were analyzed. The predominance of green algae with a significant diversity of green flagellates and the complete absence of cyanobacteria are typical features of forest soils. The small number of detected species (12 in beech relict forests and 15 in artificial beech plantations) indicates shaded forest ecosystems which are typical for beech forests. Despite common features, the species composition of soil algae of both phytocenoses is quite different. The soils under the beech relict forests are characterized by a significant predominance of green algae, among which essential number of Trebouxiophyceae representatives with aerophytic ecology were found. It indicates the mountainous nature of the soil algal flora. Soils under artificial beech plantations are characterized by a richer species diversity and predominance of Chlorophyceae representatives, which is typical for lowland forests. A characteristic feature of protected and artificially created beech forests was the relative high number of micromycetes. Correlation analysis of research results showed a positive relationship between algal diversity and the abundance of two eco-trophic groups of microorganisms: actinomycetes and ammonifiers. In addition, the growth of algal diversity was positively correlated with the content of Ca and Mg, and negatively with the content of P.

Investigations were carried out in the ecosystem of the Kuyalnyk estuary during high water period in 2004-2007. Relationships between the species diversity of microalgae and their quantitative characteristics (cell numbers and biomass) and abiotic factors, including hydrophysical (water temperature, transparency, and suspended matter content), meteorological (precipitation sum), and hydrochemical (water salinity, the content of nitrogen, phosphorus, and silicon inorganic compounds, dissolved oxygen, readily oxidized organic matter, and pH) ones, were analyzed in different seasons. It has been shown that the biomass of microalgae in the Kuyalnyk estuary during vegetation season from April until October 2004-2007 correlated well with water level (r = -0.69) and water salinity (r = 0.71), and also with the content of mineral phosphorus (r = 0.77). The correlation with other abiotic factors was not so significant and depended on season.

Results of analysis of original data obtained in 2001-2018 on the ecology and biogeographic distribution of 40 species (45 infraspecific taxa) of Chlorophyta of the orders Cladophorales (8), Ulotrichales (4), Ulvales (6), Chlo-rellales (1), Chlamydomonadales (6), and Sphaeropleales (20) and 7 species of Charophyta of the orders Zygnematales (2), Desmidiales (4), and Charales (1) of the hyperhaline Kuyalnyk estuary, its main tributaries and various water bodies located within the two-kilometer water protection zone are given in the paper. The ecological characteristics (relationship to pH, water salinity, organic matter content, and ecotopic confinement) and the environmental conditions of habitats (temperature, water salinity, pH, and the content of inorganic compounds of nitrogen and phosphorus) are given in the paper. In the hyperhaline Kuyalnyk estuary, the concentration of nutrients (nitrogen and phosphorus) was high during all water periods. The increase in water salinity up to 200-320‰ resulted in the decrease in species diversity, changes in the structure of algal communities, and also in a predominance of species ofthe genus Dunaliella Teod. (Chlorophyta).

This paper presents a review of long-term (2001–2018) original studies of the algae flora of the hyperhaline Kuyalnyk estuary, 6 tributaries flowing into it (rivers, streams, water channels from ponds), ephemeral reservoirs located along the estuary and 5 adjacent reservoirs of different types (ponds, reservoirs). The features of distribution algae species in Kuyalnyk estuary and distribution of these organisms in the water bodies of the estuary basin, as well as the main environmental factors influencing the formation of their species composition are analyzed. A total of 270 species (274 ist) of algae (phytoplankton, micro- and macrophytobenthos, periphyton) from 9 divisions (Cyanoprokaryota – 45 species (46 ist), Bacillariophyta – 159 species (161 ist), Chlorophyta – 37 species (38 ist), Euglenophyta – 16 species, Charophyta – 7 species, Chrysophyta – 3 species, Xanthophyta, Dinophyta and Haptophyta – 1 species each. Diatom algae (Bacillariophyta) – 61 species (82% of the total number of species found in each of the studied reservoirs) with a predominance of species of the genus Navicula prevail in terms of species richness in the algae flora of the estuary basin. Second and third places are shared by Cyanoprokaryota and Chlorophyta. At the time of the study, 18 species of macrophytes were identified in these water bodies. A number of identified species are characterized by high physiological fitness and rapid response to changes in environmental conditions: Phormidium breve (Kütz. ex Gomont) Anagn. et Komárek, Spirulina major Kütz., S. meneghiniana (Zanardini ex Gomont) W.B.Grow, Cyclotella meneghiniana Kütz., Ctenophora pulchera (Raits ex Kütz.) D.M.Williams ex Round, Rhoicosphenia abbreviata (C.Agardh.) Lange-Bert., Tabularia tabulata (C.Agardh) Snoeijs, Ulnaria ulna (Nitzsch.) Compere, Achnanthes brevipes C.Agardh var brevipes, Platesa salinarum (Grunow) Lange-Bert., Fallacia pygmaea (Kütz.) Stick et D.G.Mann, Navicula cryptocephala Kütz., N. gregaria Donkin, Bacillaria paxillifera (O.Müll.) T.Marsson, Cylindrotheca closterium (Ehrenb.) Reimann et G.C.Levin, Tryblionella apiculata W.Greg., T. hungarica (Grunow) Frenguelli, Surirella striatula Turpin, S. minuta Bréb. ex Kütz., Dunaliella Salina (Dunal) Teodor. Mineralization as a factor influencing the structure of algal communities is most severe in the Kuyalnyk estuary, in the confluence of the tributaries and estuaries, controlling the composition of dominant species.

The combined effect of green microalgae Chlorella vulgaris and siliceous organo-mineral fertilizer (analcite + peat (pH 5.8) in a ratio of 1 : 3) on the characteristics of growth, development, photosynthetic productivity, yield and fruit quality of sweet pepper (Capsicum annuum L., variety "Bieloziorka"), as well as microbiocenosis, allelopathic and agronomic characteristics of the soil was studied in pot experiments. The microalgae culture medium was applied in a volume of 10 mL per a pot (0.7 L) with sifted and sterilized gray podzolic soil. Plants were grown in a phytochamber under controlled conditions of light, temperature and soil moisture. The vitality of the pepper plants was assessed by morphometric growth characteristics (shoot height, stem diameter, leaf surface area, length of roots, shoot and root dry weights, quantity and weight of fruits), content of photosynthetic pigments in leaves, protective antioxidants (carotenoids, flavonoids and anthocyanins) in fruits. At the end of the experiment, the content of phenolics, electric conductivity, redox potential, pH, the content of NH4+, NO3- and HCO3- in the soil solution were determined. A synergistic enhancement of the positive effect of microalgae and siliceous organo-mineral fertilizer on the growth, development, productivity and yield quality of sweet peppers has been established. The combined application of chlorella culture medium with siliceous organo-mineral fertilizer more effectively improved agronomic and allelopathic characteristics of the soil, stimulated the development of agronomically useful ecological and trophic groups of microorganisms, the intensity of mineralization and transformation of organic matter compared to control and treatments in which microalgae or fertilizer were applied separately.

The results of the analysis of retrospective and original researches of algoflora of a hyperhaline Kuyalnyk Estuary (KE) for the 150-year period are resulted. The current state and long-term variability of the species composition and structure of algae of aquatic and soil forms of the estuary, the peculiarities of their ecotopic confinement to the factors of salinity, pH, saprobity are given. During the many years of research in the waters of KE 237 algal taxa from 10 divisions, 13 classes, 34 orders, 72 families, 98 genera, and in soil ecotopes of the estuary – 99 taxa from 50 genera, 29 families, 17 orders, 5 classes and 4 departments were found. In the modern period (2001–2018) there are 123 taxa of algae – representatives of 61 genera, 43 families, 22 orders, 7 classes and 4 divisions, in soil ecotopes – 93 species from 4 divisions were registered in the estuary. In all periods of research in the aquatic ecotopes of the estuary, representatives of Bacillariophyta dominate, and in the soil ecotopes of the coast – Cyanoprokaryota, of which 54 taxa were given for the first time for KE. It is shown that hypergalinic KE is characterized by both intraannual and interannual variability of algal species composition. It was found that the main factor limiting the biodiversity of algae is the salinity of their growth environment. The data obtained allowed to determine the features of the development of seasonal complexes of species and the dynamics of their interannual changes in 2001–2018, taking into account the hydrochemical conditions in certain years. The cosmopolitan (71%) and boreal (25%) groups predominate in relation to the biogeographical distribution of algae.

Based on the collected data on the diversity of microalgae and environmental indicators in dry and wet seasons during 2011–2018, from 45 samples, 59 species of microalgae were identified in the ornithological object—Lake Agmon in the Hula Valley. In the samples of periphyton and microphytobenthos, diatoms predominated. Bioindication analysis and statistical mapping revealed the most pronounced zones of influence on the lake ecosystem, as well as indicators of the environment and diversity that clearly demonstrate them. The correlation between the distribution of TDS of water over the lake surface and the distribution of green, diatom microalgae and cyanobacteria detected two areas of impact from the old channel of the Jordan River in the northwestern part and from the drainage channel in the northeastern parts of the lake. The area on the east coast, in contact with the resting fields of migratory birds, has provided nutrients that stimulate the development of green algae and cyanobacteria. This showed implicit links in the lake ecosystem using bioindicators make it possible to recommend them for monitoring in combination with statistical mapping, which visualizes the distribution of data and is easily accessible for the decision-making system for the management of a protected ornithological lake.

The dynamics of seasonal development of the algae flora of the Kuyalnyk Estuary in 2001–2018 is considered. A significant spatial heterogeneity of the distribution of microalgae in the water area of the estuary in different seasons of the growing season was established. The lowest and highest indicators of the number and biomass of microalgae were observed in the shallow waters of the northern part of the estuary.

he present studies were carried out to evaluate a potential biofuel application of the native strain Monoraphidium sp. IBASU-A 574 (Selenastraceae, Chlorophyta) adapted to the temperate zone climatic conditions. This strain was isolated from a small freshwater lake situated in Kyiv-city (Ukraine) by the reached culture method for obtaining desired strains of different species with high growth rate. It was identified based on its morphological characterization under light microscopy and 18S rRNA sequence analysis. Its culture’s growth, kinetic characteristics (specific growth rate and productivity) and biological peculiarities of the investigated strain were studied in comparison with the well-known biomass producer Chlorella vulgaris Beijer. CALU 157 under the same autotrophic cultivating conditions with using the modified Tamiya medium. It was established an active growth of Monoraphidium sp. IBASU-A 574 which was practically equal to the well-known producer and characterized by following parameters: a maximum cell density of 248 ∙ 10-6 cells ∙ mL-1, the specific growth rate of 1.4 days-1 and productivity of 72.5 ∙ 10-6 cells ∙ mL-1 ∙ days-1. The results of gas-liquid chromatography analysis showed that a fatty acid profile of this microalga included a complex of palmitic (C16: 0), oleic (C18: 1), linoleic (C18: 2) and linolenic (C18: 3) major fatty acids with suitable proportion for developing biodiesel feedstocks. Moreover, there was considerable variation in formation of its fatty acid composition depending on the stage of growth, that confirmed the necessity for such studies to determine both optimal time for growing algae and gaing maximum yield of target products. Thus, Monoraphidium sp. IBASU-A 574 was found to be the promising producer of biomass for bioenergetic industry due to obtained data of its growth characteristics and suitable fatty acid profile of lipids.

The species diversity of algae in different ecotopes of the alpine lake Nesamovyte was studied. In total, 233 species were identified comprising globally and regionally rare species. We also documented a temporal change in species composition from the first investigations conducted 100 years ago to present. An increase in the species diversity of Bacillariophyta and Chlorophyta, the constancy of the number of Euglenophyta and Cyanoprocaryota species, a decrease in the composition of Charophyta and the disappearance of Dinophyta species were revealed. We further documented some changes in the most abundant species and indicator species for certain limnological conditions, the disappearance of montane species and the colonization of species with a wide ecologicalgeographical amplitude. Benthic and plankton-benthic conditions became dominant and indicators of low-alkaline mesotrophic waters as well as mass development (“blooming”) of some species increased. The studied features of the species diversity of the “algoflora” indicate high species richness and high number of indicator species, as well as lake ecosystem degradation and an increase in organic pollution. Overall, there was a shift of the lake from oligotrophic to mesotrophic state, as indicated by certain algal groups. The noted changes in the species diversity of algae in Lake Nesamovyte could be attributed to the increased anthropogenic influence leading to change of the trophic status of the lake.

The morphological characteristics, growth peculiarities, and accumulation of biologically valuable compounds and fatty acids by the strain of the green microalga Monoraphidium sp. HPDP-105 were investigated. It has been found that the studied strain is mesothermophilous. The highest intensity of its functioning is observed at 22-28°C and at the illumination of 1500 Lx. During the period of active growth, the contribution of proteins accounted for 10.4-13.3%, the contribution of carbohydrates - 14.4-23.5%, and that of lipids - 32.0-44.5% of dry mass. In terms of the content of lipids, Monoraphidium sp. HPDP-105 belongs to the strains with a high productivity. In this case, a high content of lipid compounds is registered at different stages of algal culture growth, which is a specific feature of this strain. The profile of fatty acids of Monoraphidium sp. includes mainly oleic acid (34.9% of the sum of fatty acids), palmitic acid (26.6%), and linoleic acid (19.0%). A high content of lipids and the amount and ratio between fatty acids suggest that this strain of microalgae can be used for biodiesel production.

An information on the collection of strains of biotechnological application as an integral part of Microalgal Culture Collection of the M.G. Kholodny Institute of Botany of NAS of Ukraine (IBASU-A) is given. The base of its funds contains some green algal strains belonging to the families of Dunaliellaceae, Chlorellaceae, Scenedesmaceae and Selenastraceae. They have been isolated from different regions of Ukraine in order to find cultures of phototrophic microorganisms – promising for biotechnology, in particular, obtaining biologically active additives for the needs of the food industry, medicine, agriculture, raw materials for the production of biofuels, as well as bioindication, biomonitoring, bioremediation of aquatic objects of the environment, etc. Overall, this special collection includs 90 strains of halophile and freshwater microalgae of 30 species, 15 genera, 7 families, 4 orders, 2 classes. All of them are considered as important objects for industrial cultivation, solution of environmental problems, and the basis for further biotechnological research.

The variability of the dimensional characteristics of 11 strains of green coccoid microalgae of five genera depending on the duration of exposure, temperature (22-34°C), light conditions (1-3 (± 0.5) kLx), and also on the composition of cultural medium, was investigated. It has been found that the dynamics of cell length and width depending on culture age and stage of its development are species specific. At the same time, cell downsizing was registered during the period of the most intensive culture growth, whereas cell enlargement was observed during the period of culture growth slowdown. In this case, cell length and its width changed not simultaneously. Culture aging was often accompanied by cell rounding. Abiotic factors (temperature, light, and nutrient medium composition) also significantly influenced cell dimensions of microalgae. Under optimal conditions, the density of algal cultures increased, whereas cell dimensions decreased.

The influence of the cultural medium of the charophyte Interfillum terricola on the allelopathic, microbiological, agrophysical and agrochemical properties of the soil have been studied in model pot experiments. Allelopathic soil regime was assessed by biological testing methods for water-soluble compounds and direct biotesting, as well as by vital indicators of plants-phytometers of winter wheat (Triticum aestivum L., variety "Smuglyanka") and fodder corn (Zea mays L., variety "Kadr 267 MB"). The seeds were sown immediately after the introduction of the culture fluid. The number of germinated seeds was recorded from the 2nd to the 8th day after sowing. The vital condition of phytometer plants was evaluated at the end of the experiments by morphometric indicators of growth (leaf surface area, dry matter biomass of aboveground parts and roots) and the content of photosynthetic pigments in the leaves. When the experiment was completed, soil samples were taken to determine the cytostatic effect of water-soluble compounds and to carry out microbiological and biochemical analyzes. Phenolic compounds were isolated from the soil by ion exchange (desorption) using an ion exchanger KU-2-8 (Н+). In parallel, the electrical conductivity, redox potential, pH and content of nutrients in the soil were determined. The stimulating effect of cultural medium on seed germination, growth and development of assimilation organs of wheat and corn plants has been revealed. The strength of the effect did not depend on the concentration of growing medium, which is characteristic of signal allelopathically active substances. Allelopathic and cytostatic activity of the soil decreased with the use of Interfillum terricola growing medium. The introduction of the cultural fluid significantly affected the number of microorganisms of different ecological and trophic groups. The lowest number of microorganisms was observed at the minimum rate of introduction of microalga medium, and its increase contributed to the growth of the number of almost all studied groups of microorganisms, indicators of transformation and mineralization of organic matter. Under the influence of the cultural medium, the content of phenolic compounds in the soil decreased by 1.1–1.6 times, especially at the norm of 10 mL. The soil treated with cultural fluid had higher rates of transformation and mineralization of organic matter than untreated. The concentration of phenolic compounds in the soil decreased, apparently, due to the activation of the microbiota resulting in the intensification of the destruction processes. An increase in the electrical conductivity of the soil with the introduction of microalgae inoculum was recorded, which may indicate the release of metal ions into the substrate. This confirms the increase in Ca and Mg.

The results of the study of the allelopathic activity of the culture medium of two species of green and charophyte microalgae (Chlorella vulgaris Beijer. and Interfillum terricola (J.B.Petersen) Mikhailyuk et al.) to winter wheat (Triticum aestivum L.) in model pot experiments with the aim to discover of physiological mechanisms of allelopathy and finding effective and safe compounds with growth-promoting effects. The microalgae culture medium was applied in a rate of 1; 3 and 10 mL per a pot (250 mL) filled with sifted and sterilized gray podzolic soil, before sowing wheat seeds. Test plants were grown in a phytochamber under controlled conditions of light intensity, temperature and soil moisture. The number of germinated seeds was recorded from the 2nd to the 8th day after sowing. The vitality of winter wheat was evaluated at the end of the experiments using morphometric characteristics of growth (height of aboveground parts, leaf surface area, length of root system, number of lateral roots; dry matter mass of aboveground parts and roots) and content of photosynthetic pigments in leaves. At the end of the experiment, the indicators of electrical conductivity, redox potential, pH and content of nutrients in the soil were determined. The positive effect of microalgae on seed germination, growth and photosynthetic apparatus of T. aestivum plants was established. Culture medium of C. vulgaris showed a higher stimulating effect on seed germination and growth of wheat seedlings than I. terricola. The positive effect of microalgae on the photosynthetic activity of wheat and the content of organic carbon in the soil indicates the possibility of developing of biofertilizers based on them in order to improve the structural and functional organization of agroecosystems. The obtained results confirmed the prospects of C. vulgaris as a biofertilizer in crops. The allelopathic effect of I. terricola on vascular plants has been studied for the first time. The important role of indirect allelopathic mechanisms in the interactions between the studied species of microalgae and vascular plants has been established.

The species diversity and changes in the structural dynamics of the algal flora from the alpine lake Nesamovyte has been studied for 100 years. During the period of investigations, 234 species (245 infraspecific taxa) were revealed to cover more than 70% of the modern species composition of the studied lake. The modern biodiversity of algae is characterized by an increase in the number of widespread forms, a change from the baseline “montane” complex in comparison to the beginning of the 20th century. Nevertheless, the Nesamovyte Lake still has a unique algae composition that is typical for high-mountainous European lakes. The presence of a different complex of conventionally arctic species of algae, in particular, diatoms is discussed. Structural changes in the taxonomic composition of the algal flora of the lake as well as in the complex of the leading genera, species and their diversity are revealed. An ecological analysis of the algal species composition of the lake showed vulnerability and degradation to the ecosystem of the lake. On this basis, the issue regarding the question of protection and preservation of the algae significance and uniqueness of the flora of algae in the Nesamovyte Lake are discussed.

Background: In Ukraine, the research works focused on the study of green microalgae as an alternative source of feedstock for biodiesel production started in 2009. The screening of the Ukrainian Microalgae Culture Collection (IBASU-A) revealed a number of promising strains of species belonging to Chlorella, Chloroidium, Desmodesmus, and Parachlorella (Chlorellaceae and Scenedesmaceae) genera. The main criteria for strain selection were: accumulation of a significant volume of lipids, high kinetic characteristics (specific growth rate and productivity), resistance to stresses and biological contaminations. Some novel algal strains with relevant properties and optimized to the local climatic conditions were also isolated from different regions of Ukraine. Biotechnological studies showed a rather high potential of many of them, especially those of species from Tetradesmus and Desmodesmus (Scenedesmaceae) genera. Recently, some strains of species belonging to Monoraphidium, Raphidocelis, and Selenastrum (Selenastraceae) genera have also been isolated and the search for strains with a high biomass production continued. Objective: Moving from an overview of the oleaginous high-efficiency strains present in the largest algal collection in Ukraine (IBASU-A) and a critical analysis of problems related to biodiesel fuel production by microalgae, here we report preliminary data on biomass productivity, lipid amount and fatty acid profiles of some Ukrainian strains of Selenastraceae family. Methods: Traditional techniques were used for the isolation of new strains. The study of growth characteristics was carried out under intensive conditions and the daily increase of algal biomass was determined by the gravimetrical method. The data obtained on growth characteristics were compared with those of the well-known producers of biomass. The fatty acid composition in the most promising strains was determined by the gas-liquid chromatography. Results: Three new algal strains, M. minutum IBASU-A 574, Monoraphidium sp. IBASU-A 377 and Raphidocelis subcapitata IBASU-A 358, of Selenastraceae, adapted to regional climatic conditions, were isolated from different regions of Ukraine. They showed a higher efficiency in biodiesel production with respect to strains of Chlorellaceae and Scenedesmaceae earlier investigated. The biomass productivity of M. minutum IBASU-A 574, Monoraphidium sp. IBASU-A 377 and Raphidocelis subcapitata IBASU-A 358 was 1.84, 0.84 and 1.32 g DW L-1·day-1, while the lipid contents were 33.65%, 29.43% and 23.14%, respectively. Their fatty acid profiles included mainly C16:0, C18:2 and C18:3, all of interest for biodiesel production. Conclusion: The Ukrainian Microalgae Culture Collection has been supplemented with strains of species from family Selenastraceae showing high-efficiency for biodiesel production and adaptation to local environmental conditions.