Bioactivity Analysis of Secondary Metabolites from Actinomycetes' Isolated from Coastal Sediments

Abstract The rising threat of antibiotic resistance underscores the need for new antibiotics. Marine actinomycetes have emerged as promising sources of bioactive compounds. In this study, 22 isolates from marine sediments were morphologically identified, with nine confirmed as actinomycetes through 16S rRNA gene sequencing. Five strains- Streptomyces olivoverticillatus (T-2), Streptomyces cyaneus (T-4), Nocardiopsis synnemataformans (T-7), Streptomyces albogriseolus (T-8), and Streptomyces atrovirens (T-9)- exhibited significant antibacterial activity. Cultured in Starch Casein Broth, their metabolites were tested for antibacterial, antioxidant, anticoagulation, and anti-inflammatory activities. T-4 and T-8 demonstrated notable antimicrobial action, T-8 showing potent DPPH radical scavenging (372.09 ± 11.05 µg/mL). T-9 inhibited trypsin (IC 50 435.12 ± 15.88 µg/mL) and had a prothrombin time of 12.08 ± 1.46 minutes. T-8 enhanced RBC membrane stabilization (IC 50 140.08 ± 2.30 µg/mL). These findings suggest that marine sediment-derived actinomycetes hold significant therapeutic potential and warrant further study.