Impacts of Intracellular Mercury Bioaccumulation on Biochemical Composition of Anabaena Variabilis

The uptake and accumulation of toxic heavy metal mercury by a fresh water planktonic cyanobacterium, Anabaena variabilis was checked out under laboratory conditions. The aim of this work was to investigate whether this fresh water planktonic alga could serve as an early warning system (or bioindicator) of increased input of Hg in the food chain. Further, the effects of this bioaccumulation was observed on different physiological parameters like growth measurements, chlorophyll, carotenoid, phycocyanin, carbohydrate, protein content and nitrate reductase activity of A. variabilis. The importance of NR activity as biological indicator (since A. variabilis is very sensitive even to the low concentrations of Hg2+) for monitoring the effects of heavy metals on the cyanobacteria is to be perceived. The study also explores the possibility of using A. variabilis for bioremediation of Hg2+.