Abstract

DIFFERENT CONCENTRATION OF COBALT TOLERANCE IN CHLORELLA VULGARIS & THEIR EFFECT ON GROWTH AND BIOPIGMENT

Namita Sikarwar and G.P.Singh

Abstract

ABSTRACT Chlorella vulgaris could be tolerant at 3.5 ppm CoCl2·6H2O and a zinc tolerant strain with maximum tolerance concentration (MTC) 10 ppm CoCl2·6H2O was obtained by stepwise transfer to higher concentrations. The adaptation was irreversible even after three generation in metal free medium. The tolerant strain grew with a shorter lag period of 4 days as against 6 days in the case of the wild strain. The tolerant strain had higher MTC than that of the wild strain. The zinc tolerant strain of Chlorella vulgaris was obtained by transferring a 10 days old wild strain from minimal medium containing known concentration of Cobalt salt. At same doses also estimated various biochemical activities including chlorophylls (chl-a, chl-b & total chl) and carotenoid in these experiment.

Keywords: Chlorella vulgaris, Cobalt tolerance,minimal media