Isolation and Molecular Identification of Streptomyces spp. Producing Antibacterial Compounds from Iranian Soil

Backgrounds: This study was conducted with the aim of isolation and molecular identification of Streptomyces spp. producing antibacterial compounds from Iranian soil. Materials & Methods: In this study, ۵۰ soil samples were collected from different areas of Sanandaj city. Soil samples were cultured on starch casein media. Streptomyces species were characterized using morphological and biochemical assays. Molecular identification was performed by ۱۶S rRNA sequencing. Antimicrobial activity was evaluated using perpendicular streak and agar well diffusion methods. Findings: To identify active Streptomyces strains in terms of producing antibacterial agents, screening was performed in two stages. Among ۲۰ Streptomyces strains isolated from soil samples, six isolates were selected in the primary screening stage based on their ability to limit the growth of pathogens. Of the two solvents used in the secondary screening stage, ethyl acetate was the most suitable solvent for extracting effective metabolites of Streptomyces. Among the six isolates selected based on their antimicrobial activity, two isolates with the highest antibacterial activity were selected for the sequencing process. By analyzing the dendrogram and the data obtained from the NCBI database, it was found that one isolate (Yellow ۴A) was ۹۸% similar to S. fradiae, and the other isolate (Green ۴A)  was ۹۸% similar to S. coelicolor. Conclusion: The use of proper strategies to identify potential new Streptomyces species with antibacterial properties may bring a bright future in the treatment of resistant pathogens. However, more studies are required to detect active metabolites of the mentioned isolates.

کلیدواژه ها:

Streptomyces coelicolor ، Streptomyces fradiae ، Soil ، PCR ، Sequencing