Isolation of Secondary Metabolites From Marine Actinobacterium of Microbispora sp.T3S11 and Their Antibacterial Activities.

Introduction Marine actinobacteria are promising sources of novel bioactive compounds due to their distinct ecological niches and diverse secondary metabolite production capabilities. Among these,  sp. T3S11 is notable for its unique spore chain structure, which allows for both morphological and genetic identification. Despite its potential, little is understood about the secondary metabolites produced by this strain. In this study, we hope to fill this gap by extracting and analyzing the antibacterial activities of secondary metabolites from  sp. T3S11, which will be the first time its bioactive compound profile is investigated. Aim To evaluate the antibacterial activity of secondary metabolites isolated from the marine actinobacterium  sp. T3S11. Materials and methods The antibacterial assays were carried out on agar plates containing the appropriate media for each pathogen. Sterile filter paper disks were impregnated with secondary metabolites extracted from  sp. T3S11 and placed on the surface of agar plates inoculated with the appropriate pathogens. Similarly, disks containing tetracycline were used as a positive control. The plates were then incubated at the appropriate temperature for each pathogen, and the zones of inhibition around the disks were measured to determine the extracted metabolites' antibacterial activity. Result Secondary metabolites had antimicrobial activity against , , and methicillin-resistant  (MRSA). The inhibition of  was 7.5 mm and 8.5 mm at 75 μg/mL and 100 μg/mL, respectively.  zones measured 7 mm and 7.5 mm, while MRSA zones measured 7.6 mm and 8.5 mm at the same concentrations. Tetracycline, the standard antibiotic, had larger inhibition zones: 22 mm for  and and 16 mm for MRSA, indicating variable susceptibility. Conclusion We conclude that the secondary metabolites extracted from  sp. T3S11 exhibits high antibacterial activity. This could be attributed to the presence of various active compounds.