The present study was carried out on microalgae Chlorella vulgaris to investigate the effect of citrate
metabolite as a nutrient for biodiesel production. The oil obtained from C. vulgaris is a promising fuel
substitute and can be used as biodiesel. C. vulgaris was cultured in conway medium at different
concentrations of citrate, namely 0.5, 1.0 and 2 g/L were added to the culture medium in different
experimental groups. Subsequently, the growth, proximate composition and biomass content of the
cultured cells were analyzed. The maximum biomass (1.6870.044 g/L) in the cultured cells was
obtained at a citrate concentration of 2.0 g/L in the culture medium. However, the highest oil yield
(28.62%) was obtained at the 1owest citrate concentration. Physico-chemical parameters such as pH,
viscosity, density, acid and iodine values of the extracted oil were analyzed. In addition, a freeze-dried
sample of the algae was analyzed to ascertain its biochemical composition. The maximum lipid content
(37.037 70.88%) was obtained at the minimum experimental concentration of citrate (0.5 g/L) in the
culture media. An increase in citrate concentration in the media resulted in a decrease in total lipid
content of the cells, but increased the carbohydrate content up to 29.4370.72%. Fatty acid profiles of the
control and experimental groups were analyzed. The present study was suggested that the presence of
lowest concentration of citrate in the culture media can improve the accumulation of lipids in C. vulgaris