A new chlorophycean nickel hyperaccumulator

Bioremediation of nickel by chlorophycean bioremediator, Chlorococcum hemicolum was investigated. The growth rates at various concentrations of Ni2+ were assessed in terms of protein level and 12 mg L(-1) of the Ni2+ is the tolerance limit (46.76% level of growth kinetics). Absorption/adsorption kinetics was estimated after 240 h of Ni2+ treatments. Absorptions were higher than adsorption with maximum accumulation factor (AF) of 1.37. Ni2+ concentration and absorption were linearly related (r=0.98; p>0.01). Other biochemical parameters like total sugar, chlorophyll and carotenoids were also quantified to correlate the state of metabolism and these exhibited reduction due to heavy metal stress.