تاثير سرب بر نرخ رشد، ميزان كلروفيل و بتاكاروتن در جلبك DUNALIELLA SALINA

Effect of Lead (pb) on Growth Rate, Chlorophyll and Beta-Carotene Content of Dunaliella Salina Isolated from Salt Marsh of Gavekhoni of Esfahan

The individual effects of Pb^2+ concentrations (0.005, 0.05 and 0.5 mg.L^-l) on the growth (cell number and total chlorophyll content) and beta-carotene synthesis of two strains (Iranian and Australian) of green alga Dunaliella salina were examined during 36 days of treatment. The effects of these concentrations on the amount of calcium and magnesium content of the cells were also evaluated. An increase in Pb^2+ concentrations caused a significant reduction in cell number and chlorophyll content of D. salina. In both strains, the increase of beta-carotene content of cells was observed in comparison with control. It seems such decrease in growth rate and increase in beta-carotene content of cells is due to deficiency of essential elements such as magnesium and calcium and also increase of free radicals due to Pb^2+ in the medium.