This review paper considers the features of the biology of cyanobacteria, their role as photosynthetics, nitrogen fixers, and producers of biologically active substances, as well as the distribution of these microorganisms in various marine ecosystems. The symbioses of marine cyanobacteria with a wide range of eukaryotic organisms are discussed.

The current study focuses on the diversity, distribution and toxic potential of cyanobacteria in the waterbodies of Moscow, Russia. The research involves the sampling of natural and artificial water environments situated within the Moscow city agglomeration, including the waterbodies of recreational importance. A total of 20 strains of cyanobacteria, namely representatives of Anabaena, Aphanizomenon, Argonema, Dolichospermum, Microcystis and Woronichinia, are isolated from the collected samples. The morphology of the newly obtained strains is analyzed through light microscopy. The results of morphological identification are compared to the molecular data. The molecular phylogeny of the cyanobacterial strains is assessed on the basis of 16S rRNA sequencing. The detection of cyanotoxin-producing genes through PCR reveals two strains of Microcystis aeruginosa capable of microcystin synthesis. Further analysis using HPLC-HRMS demonstrates that microcystin production includes a high proportion (20–28%) of exceptionally toxic microcystin–leucine arginine compounds. Hereby, we discuss the morphology and phylogeny of the analyzed strains and provide comments on the toxic potential of cyanobacteria within the waterbodies of Moscow.

The applicability of confocal laser scanning microscopy (CLSM) for environmental monitoring of water bodies is demonstrated on several examples. Such CLSM methods as spectral imaging and microscopic spectroscopy of living cyanobacterial cells are considered. It is shown that fluorescence spectroscopy application can facilitate time-consuming process of taxonomic analysis of field samples and to make monitoring of water bodies during cyanobacterial blooms, on-line.

Bioresource collections represent a way of preserving biodiversity, making it accessible to many generations of researchers. The complex of bioresource collections of St. Petersburg State University is presented by about 40 bioresource collections, consisting of both preserved specimens and living organisms. The total number of specimens in the bioresource collections of the University exceeds one million. The history of the formation and study of bioresource collections reflects the history of the development of the University as a whole. Although some samples of the collections are more than 300 years old, many were obtained in recent years. The oldest bioresource collections of the University are the herbarium and the educational and scientific museum collection of invertebrates; examples of the newest collections involve the collection of genetically modified lines of laboratory animals, the collection of model species of naturally transgenic plants and natural transgenes, and the collections of insect genetic materials. In general, current bioresource collections of SPbSU are divided into five groups: (1) herbarium; (2) zoological collections; (3) botanical garden; (4) collections of microorganisms; (5) genetic collections. Bioresource collections of SPbSU are actively used both in the educational process and in scientific work. In this review, we discuss in detail the bioresource collections of SPbSU focusing on their current state, application, and future prospects.

The relevance of researching the biotechnological potential of cyanobacteria is linked to an existing contradiction: despite extensive fundamental knowledge about the biotechnological potential of cyanobacteria, their commercial application is limited to a narrow niche. The key tasks in this regard are selecting highly productive strains or consortia and developing cultivation methods that increase the yield of target metabolites. Eight cyanobacterial cultures from the SPbU Science Park collection (CALU), isolated from various geographical regions, were reconstructed and characterized as cyanobacterial-bacterial consortia in terms of biomass growth and biochemical composition using standard methods of chemical composition analysis, factorial experiments, thin-layer chromatography, spectrophotometry, the clotting method, and 16S rRNA profiling. The results of two-step full factorial experiment showed significant variability in the total content of metabolites (proteins, carbohydrates, lipids, and pigments) but not biomass growth in different cultures when varying the photoperiod regime and/or the ratio of inorganic nitrogen and phosphorus (N/P) sources in the nutrient medium. Statistically significant anticoagulant activity was observed in the extracellular polymers in 5 of 8 cyanobacterial-bacterial consortia studied. These results suggest that further research should focus on the extracellular metabolites of cyanobacteria, as they are the most promising targets for commercial product development.