Impact of cobalt chloride on growth and biopigments of Chlorella Vulgaris

Chlorella vulgaris is single cell green algae, which has many nutritive and pharmaceutical values. The effects of cobalt chloride on growth, chlorophyll a, chlorophyll b and carotenoids of Chlorella vulgaris were determined. The growth in terms of optical density, dry weight and fresh weight was slightly increased with increasing concentrations of CoCl2 (upto 2ppm) but in higher concentrations (>2ppm) growth was reduced constantly, best growth was found in cultures treated with 2ppm cobalt chloride. The results of biopigment analysis were also correlates with growth results, highest amount of biopigments were found in moderate concentrations of CoCl2. Results indicate the tolerance range of algae for heavy metal and useful to increase its nutritive value. OD: Optical density, FW: Fresh weight, DW: Dry weight, ppm: Parts per million, Chl: Chlorophyll, HM: Heavy metal