Ecology, Environment and Conservation Paper

OXIDATIVE STRESS EFFECTS OF ZINC OXIDE NANOPARTICLES ON FRESH WATER MICROALGA HAEMATOCOCCUS PLUVIALIS

Sinouvassane Djearamane, Ling Shing Wong, Yang Mooi Lim and Poh Foong Lee

Abstract

Zinc oxide nano particles (ZnO NPs) are enormously utilized in the consumer products in recent days due to their unique physio-chemical properties. Such substantial application in commercial products has resulted in the huge release of ZnO NPs into the environment, especially aquatic environment. The presence of ZnO NPs in the aquatic environment might result in the growth inhibition of aquatic organisms through induction of oxidative stress by the excessive release of reactive oxygen species (ROS) and the subsequent lipid per oxidation. Thus, the present study has investigated the oxidative stress effects of ZnO NPs in fresh water microalga Haematococcus pluvialis. The microalgal cells were exposed to the increasing concentrations of ZnO NPs from 10 to 200 mg/L over a period of 96 h at an interval of 24 h to explore the dose- and time dependent oxidative stress effects of ZnO NPs in algal cells. The study results revealed a typical concentration and time-dependent increase in reactive oxygen species and lipid per oxidation levels. Hence, the present study suggest the potential of microalga H. pluvialis to be used as a bio-indicator of ZnO NPs in aquatic environment due to the profound sensitivity of H. pluvialis towards ZnO NPs toxicity.