Effect of copper, cadmium and mercury on the morphological, physiological and biochemical characteristics of Scenedesmus quadricauda (Turp.) de Breb.

Abstract

The coenobial green alga Scenedesmus quadricauda (Turp.) de Breb. was treated with different concentrations of copper, cadmium and mercury. The effect of these heavy metals on the morphological, physiological and biochemical characteristics of the alga was investigated. The toxicity of the metals was found in the order of Hg > Cu > Cd. Although no distinct morphological abnormalities were observed at the lower metal concentrations but the colonies exhibited chlorosis and cell lysis at the higher concentrations. A maximum inhibition in the growth, chlorophylls, total DNA, total RNA and protein content of the cells was observed at the higher metal concentrations. It was interestingly observed that the chlorophyll b was more sensitive than chlorophyll a at all the concentrations of the test metals.