A novel strain of Saccaropolyspora hirsuta was isolated from an insect Tapinoma simrothi for the first time and was morphologically and physiologically characterized. It was genetically identified using 16S rRNA and sequence similarity percentage in genbank with closely related species as strain ess_amA6 of Saccaropolyspora hirsuta. The accession number of strain ess_amA6 is KF996506. Antagonistic activity of strain ess_amA6 against some pathogenic Gram positive and negative bacteria, and unicellular fungus Candida albicans was studied. In addition, star shaped silver nanoparticles were biosynthesized using strain ess_amA6. The silver Nano stars were characterized by UV-us spectrophotometer. Fourier transform infrared spectroscopy analysis confirmed the conversion of Ag+ ions to Nano silver due to the reduction by capping material of extract. Transmission electron microscopically studies of biosynthesized Nano silver particles showed that they are spherical ranging from 10 nm to 30 nm in size. Silver atoms were checked in Nano sample by Energy Dispersive X-ray spectroscopy. Bioactivity of biosynthesized Nano silver was observed against some pathogenic microorganisms such as Staphylococcus aureus, Streptococcus pyogenes, Salmonella typhi, pseudomonas aeruginosa, Klebsiella pneumonia and Candida albicans. These tested microbes were highly sensitive to Nano silver. This study recommended that strain ess_amA6 can be used to effectively biosynthesize bioactive Nano silver compounds.
Keywords: Antimicrobial; Nano silver; Pathogenic microbes; Saccharopolyspora hirsute.