Assessment of the Biotechnological Potential of Cyanobacteria from the Calu Collection: Influence of Strain and Cultivation Conditions

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.