Streptomyces violaceoruber ES: A Producer of Bioprospective Metabolite for Rapid and Green Synthesis of Antibacterial Silver Nanoparticles

Abstract

AN ISOLATE of Streptomyces was phenotypically, morphologically and physiologically characterized and identified as Streptomyces violaceoruber ES. Its identification was confirmed using 16S rRNA gene sequencing. It produced a metabolite containing deep pink pigment that might be involved in silver nanoparticles (AgNPs) biosynthesis. Both crude metabolite on starch nitrate medium and partially purified metabolite with ammonium sulphate precipitation were tested for AgNPs synthesis. The biosynthesis protocol had environmental advantages of green synthesis and superior nanoparticles properties included regular rounded shape, size range from 13 nm to 27 nm, and bactericidal efficiency. The AgNPs synthesis was performed within one minute at room temperature and sun light. This guarantees high biosafety, low cost, less consumption of energy, rapid and simplicity of its biosynthesis. Furthermore, the synthesized AgNPs showed antibacterial activity against multidrug resistant strains of E. coli, K. pneumoniae and P. aeruginosa. Also, it had synergistic effect with gentamycin against P. aeruginosa.