Impact of Different Concentrations of Zinc and Cadmium Chloride on Micro Algae Chroococcus Minutus

In the present investigation the effect of different concentrations of zinc and cadmium chloride (ZnCl2 and CdCl2) on one of the Cyanophyta "Chroococcus minutus" isolated from ponds in Sanaʹa Yemen was evaluated. The two heavy metals adversely affected cell division; however the protein and glucose contents of the cells were slightly affected. They caused destruction of chlorophyll a as the result obtained by measuring the optical density and the chlorophyll content. These observations were interpreted in terms of the action of metals on the reduction and oxidation steps in the biosynthesis pathway of pigments