Antibacterial and antioxidant activities of Streptomyces sp. strain FR7 isolated from forest soil.

This article focuses on the isolation and characterization of Streptomyces sp. strain FR7 from soil in the Raf Raf forest (Tunisia) for its antibacterial and antioxidant potential. Under optimized culture conditions (ISP2 medium, pH 8, 30°C, 10 days), an ethyl acetate extract from strain FR7 exhibited significant antimicrobial activity against both Gram-positive bacteria (e.g., Micrococcus luteus, Staphylococcus aureus) and some Gram-negative bacteria (e.g., Pseudomonas aeruginosa), with minimum inhibitory concentrations as low as 5 μg/ml. The extract also demonstrated strong antioxidant activity, including free radical scavenging and protection of yeast cells from oxidative stress. Mass spectrometry analysis identified polyketide compounds, including methylsalicylic acid moieties, which are likely responsible for the observed bioactivities. These findings suggest that Streptomyces sp. FR7 is a promising source of bioactive metabolites with potential applications in medicine, veterinary, and agriculture.