Antimicrobial activity of silver nanoparticles by Pleurotus citrinopileatus and Pleurotus eryngii

Integration of microorganisms to nanotechnol. is one of the key issues in nanoscience research. There is growing need to develop environmentally benign metal nanoparticle synthesis process that do not use toxic chems. in the synthesis protocols to avoid adverse effects in medical applications. The use of microorganisms in the synthesis of nanoparticles emerges as an eco-​friendly approach. In the present study, antimicrobial activity of biosynthesized silver nanoparticles using edible mushrooms viz., Pleurotus citrinopileatus and Pleurotus eryngii, and partial characterization of silver nanoparticle have been reported. It was found that aq. silver ions of 1-​5mM concns. were reduced to silver metal nanoparticles by nitrate dependent reductase and a shuttle quinone extracellular process when treated with fungal supernatant of Pleurotus citrinopileatus in 72 h at 1 mM and Pleurotus eryngii in 48 h at 4 mM. Partial characterization of synthesized silver nanoparticle, investigated by UV-​VIS Spectroscopy showed increased productivity at 386 nm with sharp and intense surface plasmon. It is found that silver nanoparticles are bound to protein through carboxylate group of amino acid residues. The synthesized silver nanoparticle showed high bactericidal activity against Gram-​pos. (Staphylococcus aureus) and Gram-​neg. (Pseudomonas aeruginosa) bacteria. The mechanism of the Ag NP bactericidal activity is discussed in terms of Ag NP interaction with the cell membranes of bacteria