Affiliation: Department of Marine and Coastal Studies, Madurai Kamaraj University, Madurai-625021, Tamilnadu, India.
The present study is focused on the applications of biosynthesized silver nanoparticles in various fields. Silver nanoparticles are synthesized in vitro using marine bacteria Shewanella algae bangaramma in the laboratory. The silver nanoparticles are characterized by using UV–Vis spectrum, TEM, FTIR, EDAX, XRD and AFM analysis. The synthesized silver nanoparticles are spherical, crystalline and 5-30 nm in diameter. They were found to have both larvicidal and bactericidal activities. There is no mortality in the control. The maximum LC 50 and LC 90 values with 95% confidential limit (4.529 mg/ml (2.478 - 5.911), 9.580 mg/ml (7.528-14.541) were observed with III- instar larvae of Lepidiota mansueta (Burmeister). In exposed groups the mortality of the larvae was significantly increased in all concentrations (p < 0.0001). The order of bactericidal activity against marine fouling bacteria is found to be Pseudomonas sp. < Vibrio cholerae < Roseobacter sp. < Alteromonas sp. To date, this is the first report on the marine bacteria mediated synthesis of silver nanoparticles in culture medium which has effective larvicidal and antifouling activities.