Exploring the Diversity and Antimicrobial Potential of Actinomycetes Isolated From Forest Soil against Pseudomonas aeruginosa

Introduction: The actinobacteria are well-known for having the ability to produce bioactive secondary metabolites that effectively target bacteria, fungi, cancer cells, and the overactive immune system. Isolation and identification of novel bioactive compounds that selectively target multidrug-resistant Pseudomonas aeruginosa were made possible from actinobacteria inhabiting soil ecosystems. Methods: The present investigation aims to isolate and characterize potent bioactive compounds from actinobacteria against MDR P. aeruginosa. The actinobacteria strains were isolated from forest soil samples using starch casein agar and their bioactive potential was determined against MDR P. aeruginosa strains by agar well diffusion method. The potent bioactive compounds produced by actinobacteria isolates against P. aeruginosa were identified using phenotypic characteristics and ۱۶S rRNA gene sequencing. The ethyl acetate and n-butanol were used for the extraction of bioactive compounds. The column chromatography was used for the purification of fractions. The potent fraction having bioactivity was elucidated structurally using UPLC-UV-MS. Results: The Streptomyces tendae and Streptomyces albidoflavus isolated from forest soil have the ability to produce bioactive compounds against MDR P. aeruginosa. S. tendae SI۰۵ produced cyclic dipeptide L,L-Cyclo(leucylprolyl), whereas S. albidoflavus SI۰۷ produced phthalate ester, diisobutyl phthalate, and non-proteinogenic peptide Norvaline. Conclusion: The bioactive compounds obtained from S. tendae SI۰۵ and S. albidoflavus SI۰۷ were effective against MDR P. aeruginosa strains. Therefore, they can be used to overcome resistance mechanisms and target virulence factors of P. aeruginosa strains.