Now a day researchers find metallic nanoparticles as a good antimicrobial agent; especially silver nanoparticle, which plays a major role due to its wide application in various fields. The synthesis of silver nanoparticles by biological method is found to be easy and cost effective. So the Green synthesis has major importance in the study of nanoparticle synthesis, rather than chemical and physical approaches. In recent years the development of resistant strains of pathogenic bacteria against antibiotics are found to be an environmental problem. So the production of silver nanoparticles (AgNPs) from various microorganisms is carrying out by researchers in order to act over these resistant pathogens by biological way. In this study, the biosynthesis of AgNPs was carried out using two fungal species viz., Aspergillus ochraceus and A. sydowii isolated from coastal sand dune of Puducherry coastal area. A comparative study was made among these two species regarding their nanoparticle characterization as well as the antibiotic efficacy over the pathogens. The silver nanoparticle formation was monitored by UV-spectrophotometer and X-ray diffraction method. The nanoparticle of both species showed antimicrobial activity towards the certain gram positive and gram negative bacteria and also showed enhanced activity by combined with antibiotic Ampicillin.
