EFFECT OF NITROGEN, PHOSPHORUS CONCENTRATIONS, pH AND SALINITY RANGES ON GROWTH, BIOMASS AND LIPID ACCUMULATION OF CHLORELLA VULGARIS

Microalgal like Chlorella vulgaris, being a unicellular green algae, is been widely studied for nitrogen and phosphorus removal and as potential feedstock for biodiesel production. This not only saves water from eutrophication but also becomes a good source of biodiesel.  Hence, if two approaches are combined we can overcome the major challenge of both eutrophication and energy crisis. In the present study we have examined the effect of decreasing Nitrogen and phosphorus concentration in medium on growth, biomass and lipid content of C. vulgaris. Significant decrease in growth and biomass was observed with the decrease of nitrogen and phosphorus concentration in the medium from (1.5g/l to 0.0g/l) and (0.04g/l to 0.0g/l) respectively. Whereas the lipid accumulation showed reverse trend of increase when the concentration of both phosphorus and nitrogen where decreased in medium. At the same time, the effect of variation in pH and saline ranges on growth, biomass and lipid content of C.vulgaris were also evaluated. The growth, biomass and lipid content showed a significant difference due to the variation in pH and saline range. The growth and lipid content was maximum at control range i.e pH 7 with respect to 6, 8 and 9. On the other hand we could see that with the increase of salinity from 0.1M to 0.25 M the growth decreased whereas the lipid content showed an increasing trend.