Abstract
Microbial synthesis of nanoparticles has a prospective to develop simple, cost-effective and eco-friendly method for production of technologically important materials. The present investigation demonstrates the role of rice rhizosphere Streptomyces sp. mediated silver nanoparticles in bio control of various plant fungal pathogens and nosocomial infection causing bacteria by in vitro antagonistic activity and agar well diffusion method respectively. Isolated actinomycetes were screened for antagonism against plant fungal pathogens and the potent strain was further screened against human pathogenic bacteria. The potential strain, VSMGT1014 was identified by microscopic, physiological, biochemical characteristics and used for synthesis of silver nanoparticles. The nanoparticles were characterised by UV-Vis Absorption spectroscopy, AFM, FTIR and Xray diffraction. The AgNPs were determined to be spherical through the observation under AFM. X- ray diffraction patterns displayed typical peaks from 24 degrees-85 degrees at position 2 theta for crystalline silver. It was found that the synthesised nanoparticles showed MIC range of 10-50 mu g/mL against selected plant fungal pathogens. Moreover these nanoparticles showed significant level of inhibition as MIC range from 10-25 mu g/mL against clinically important pathogenic bacteria. Through this investigation, we concluding with Streptomyces sp. VSMGT1014 mediated silver nanoparticles would be a potential nanomedicine against various pathogenic organisms.