Biochemical Analyses of Ten Cyanobacterial and Microalgal Strains Isolated from Egyptian Habitats, and Screening for Their Potential against Some Selected Phytopathogenic Fungal Strains

Microalgae and cyanobacteria are rich sources of numerous phytochemical compounds with intrinsic antifungal potential. This research aimed to screen the contents, as well antioxidant profiles, in eight cyanobacterial two microalgal strains isolated from soil brackish water habitats Egypt. Our study also evaluated their activities against three phytopathogenic fungi—namely, Pythium ultimum, Fusarium solani, Botryodiplodia theobromae, which known cause severe plant loss. The biochemical were obtained algal methanolic extracts, identified through comparative analyses related inhibition fungal pathogens. Comparative qualitative alkaloids, steroids, glycosides, saponins carried out. quantitative screening investigated revealed presence xylanase, glucanase, chitinase enzymes, along some bioactive compounds, such phenolics, flavonoids, proteins, neutral sugars, carotenoids, species-dependent detected variable amounts extracts. unicellular green strain Dunaliella sp. HSSASE13 displayed highest level activity. However, shown by heterocystous Anabaena HSSASE11 (83.94%), followed (81.94%) non-heterocystous Oscillatoria nigro-viridis HSSASE 15 (63.42%), pathogens B. F. P. respectively. results indicate that significant positive correlations flavonoids (r = 0.854), phenolics 0.785), DPPH scavenging activity 0.876), total proteins 0.808), xylanase glucanase 0.746), sugars 0.764), terms activities, recorded solani. Conclusively, tested present can be useful agents for management biocontrol plant-infecting