LAUSR

Abstract Cyanobacteria are rich sources of structurally novel and biologically active metabolites with antibacterial, antiviral, antifungal, and anticancer activities. The present study aimed to evaluate the antimicrobial, antioxidant, and toxicity potential of freshwater filamentous cyanobacterial species isolated from a freshwater source in Kancheepuram district and Thiruverumbur, Tamilnadu. Among the tested two cyanobacterial species, methanol-chloroform extracts of Oscillatoria sp. SSCM01 exhibits higher antibacterial activity than Phormidium sp. SSCM02. Oscillatoria sp. SSCM01 exhibited higher inhibition activity of bacterial growth at 31.2 μg/mL and 7.8 μg/mL as MIC value against Staphylococcus aureus, Salmonella typhi, respectively, and for Candida albicans at 125 μg/mL. Antioxidant activity of Oscillatoria sp. SSCM01 extract assessed by DPPH assay exhibited potent radical scavenging activity of 48% inhibition at 60 μg/mL concentration. Two cyanobacterial extracts exhibited significant activity against brine shrimp larvae (Artemia salina). The active fraction was subsequently analyzed by gas chromatography-mass spectrometry (GC-MS), bioactive compounds like hexadecanoic acid (66.3%), 1, 2-benzene dicarboxylic acid, and dibutyl phthalate were detected in Oscillatoria sp. SSCM01. Thus, our findings indicate that freshwater cyanobacteria Oscillatoria sp. SSCM01 has an inherent capability that might make it beneficial as a promising source of antimicrobial and antioxidant therapeutic agents.