Effect of different dosages of zinc on the growth and biomass in five marine microalgae

Abstract

Marine environment often restrain toxic heavy metals that may enter into the food web via uptake by microalgae and eventually cause severe poisoning problems at higher tropic levels. The effects of Zinc cations upon growth of five native microalgal species, Chlorella marina, Isochrysis galbana, Tetraselmis sp., Nannochloropsis sp., and Dunaliella salina were evaluated. Growth inhibition of the microalgal cells were determined by exposing them to different concentrations of aqueous solutions of zinc metal for 15 days. A major reduction in cell density was observed in all the five cultures in the concentration of 50 ppm. Among the five micro algal species tested, Tetraselmis sp. alone showed growth up to 250 ppm concentration of zinc metal till the final day (15 th day) of experiment.