ABSTRACT
The present work was carried out for the synthesis and characterization of silver nanoparticles of green microalga Desmococcus olivaceus and to evaluate its antioxidant, antimicrobial and anti proliferative activities. The maximum synthesis of silver nanoparticle(AgNP) was obtained in 5% algal extract and 1mM silver nitrate within 48 hours at 37°C. AgNP’s were characterized by using UV-visible spectroscopy, Scanning electron microscopy EDAX and Fourier transform spectroscopy(FTIR). Silver Surface Plasmon Resonance (SPR) occurred at 430 nm for 1mM AgNP’s respectively.SEM EDAX analysis showed the presence of polydispersed, spherical AgNP’s . FTIR spectra revealed the presence of reducing groups in the extract responsible for AgNP synthesis .The synthesized AgNP exhibited superoxide and nitric oxide radical scavenging activities. Microalgal silver nanoparticles demonstrated antibacterial activity against gram positive and negative bacteria which includes Staphylococcus aureus,Bacillus subtilis, Klebsiella pneumoniae and Escherichia coli . The invitro anti proliferative activity was confirmed by MTT assay in the cell lines of cervical cancer Hela cells and vero cell lines showed IC50 value of silver nanoparticles at 1.56 & 7.04 µg/ml respectively.
