Lipid

Effect of different concentrations of nitrogen (N) source (NaNO3) of BG-11 medium on growth of freshwater microalgae Chlorella vulgaris is studied. Different nitrogen step down concentrations of NaNO3 in per litre of medium were used like 17.6 mM (control), 8.8 mM and 4.4 mM. Optimum lipid was obtained with treatment of 8.8 mM NaNO3 concentration that showed 29.30 µg lipid per 100 µg of biomass. However, biomass in term of protein was higher (602.64±0.97 µg/ml) at 17.6 mM of NaNO3 concentration. Treatment of 4.4 mM NaNO3 concentration resulted in 20.03 µg of lipid per 100 µg biomass, which was higher than control, but with poor yield of biomass. Result indicates that changing the N concentration in BG-11 medium result in enhanced lipid production in Chlorella vulgaris.