AgNPs break the wall cell in Chlorella vulgaris by oxidative stress generation

Abstract

Silver nanoparticles are used commercially due in part to its antibacterial power. However, due to their nanoscale size, these may not be retained by filters wastewater reaching the aquatic environment, which could affect microorganisms of initial food-chain as microalgae. The purpose of this study was to elucidate the cytotoxic effects of silver nanoparticles (3-7nm) in freshwater phytoplankton (Chlorella vulgaris) ex situ. Silver nanoparticles synthesis was performed according to silver nitrate chemical reduction, they were characterized by scanning electron microscope. C. vulgaris collected from Chapala Lake, Jalisco, México, was kept under laboratory conditions. C. vulgaris, grown in Bristol broth, were exposed to different concentrations of silver nanoparticles (0.01, 0.1 and 1mg L-1) for 24 hours. An important cytotoxic effect was determined in C. vulgaris exposed to silver nanoparticles, manifested by decrement in Chlorophyll-a contents, morphological changes, prominent perforations in cell walls, important decrement of lipid contents and oxidative stress generation, that corresponding to the nanoparticle concentration.