Effect of some organic acids and calcium on growth, toxic effect and accumulation of cadmium in Stigeoclonium tenue kutz

The effect of organic acids viz., citrate (CIT), malate (MAL), succinate (SUC) and calcium on cadmium toxicity, accumulation and growth in Stigeoclonium tenue Kutz. has been studied. Organic acids normally increase the growth of the alga in terms of dry weight, total chlorophyll and protein content. Succinate was found to be most effective followed by malate in reducing the toxic effect of cadmium. The addition of organic acids resulted in the increase of internal cadmium levels but decreased the toxic effect of cadmium on growth. Similarly in the absence of calcium, cadmium showed more toxic effect. In contrast to the effect oforganic acids, calcium not only reduced the toxic effect of cadmium but also decreased the uptake of cadmium by the alga.