B.Vasudeva Rao and Dr. M. Boominathan
In the present study, antibacterial activity of silver nanoparticles synthesized from the seaweeds of Ulothrixflacca, Ulva fasciata and Caulerpataxifolia were analyzed against four gram positive and gram negative bacterial strains of common fish and human pathogens. As these pathogens cause enormous damage to aquaculture as well as pose harmful threat to humans and their emergence as multidrugresistant strains is a major problem in the control of infections. Further antibacterial activity of silver nanoparticles prepared from seaweeds against eight pathogenic strains was determined by agar well diffusion assay and MIC was estimated by qualitative experimentation by micro broth dilution method. IC50 values were also studied using spectrophotometry. All experiments were done in triplicate. The silver nanoparticles of Ulothrixflacca, Ulva fasciata and Caulerpataxifolia showed the zone of inhibition ranges from 0.7± 0.6 to 26.3±0.6mm. The average IC50 values of the methanol extracts of Ulva fasciata, Caulerpataxifolia and Ulothrixflacca are 57μg/ml, 61μg/ml and 59μg/ml respectively. Silver nanoparticles from Ulothrixflacca, Ulva fasciata and Caulerpataxifoliapossess very good antibacterial activity which makes them a potent source of antibacterial agent. Keywords: Antibacterial activity, Silver nanoparti
