Antibacterial activity and biogenesis of silver and zinc nanoparticles by Streptomyces sp. strain ANB 1 isolated from marine water of Port Blair, India

The uncontrolled and random misuse of commercial antibiotics has led to the ever-increasing rise in drug resistant bacteria. There is still a lag between the development of novel drugs and the emergence of drug resistant microorganisms. Thus, multi-drug resistant microorganisms pose a serious threat to the human race. The marine environment has a great biodiversity and is largely unexplored. It has proved to be an excellent source for isolating microorganisms that produce secondary metabolites with unique properties. In the present study, the focus was to appraise the hostile behavior of marine environment and isolate actinomycetes, which are capable of having antibacterial activity and also to synthesise metallic nanoparticles. Biogenic metal nanoparticles bear immense potential as an alternative to conventional antibiotics. Out of 15 actinobacterial isolates, ANB 1 identified as Streptomyces sp. strain ANB 1 showed the most efficient antagonistic activity against the clinical pathogens Klebsiella sp., Proteus sp., Escherichia coli, Pseudomonas sp. and Bacillus sp. The inhibition zones varied in diameter from 5 – 20 mm. Further, Streptomyces sp. strain ANB 1 successfully synthesised silver and zinc nanoparticles, which were characterised by the formation of characteristic peaks in the UV-Vis spectrophotometer. The nanoparticles thus produced bear immense potential as an alternative to treat multi-drug resistant pathogens.