Characterization of filamentous cyanobacteria strains from the inland waters of Türkiye

ABSTRACT: Identification of cyanobacteria based solely on morphological features is challenging due to varying physiological and morphological characteristics according to environmental conditions which may lead to their misidentification. Therefore, using morphological, molecular, and biochemical parameters to characterize cyanobacterial isolates has been suggested for more reliable results. This study characterized two cyanobacterial isolates from Türkiye using multiple assays. Morphological and molecular description were performed as well as biochemical composition including protein, lipid, and exopolysaccharide (EPS) content, amino acids and fatty acid methyl esters profile was determined. Additionally, total phenolic content and DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity were investigated. The isolates were described as Geitlerinema splendidum and Leptolyngbya tenuis morphologically while they were identified as Nodosilinea sp. and Leptolyngbya angustata based on 16S rRNA sequencing. They both produce high quantities of EPS, consist of protein more than half of their dry biomass with a diverse set of amino acids, and have a DPPH scavenging activity. Cyanobacterial species have been presented using an integrative approach with high EPS production, total protein content, and antioxidant activity, suggesting its potential for contributing to food supplements with possible health impact.