<b>Optimizing Stress Parameters for Improving Lipid Accumulation in Heterotrophic Microalgae Cultivation for Biodiesel Production</b> In recent years, increasing consumption of conventional energy has caused serious concerns about energy security and environmental degradation. Microalgae are a diverse group of prokaryotic and eukaryotic photosynthetic microorganisms that grow rapidly due to their simple structure. It has long been considered as a promising alternative and renewable feedstock source for biofuels. It is 3rd generation fuel, because as compared with terrestrial plants, microalgae have a high oil content and growth rate. In microalgae triacylglycerides TAGs generally served as energy storage that, once extracted, can be easily converted into biodiesel through trans esterification reactions. Heterotrophic systems are more suitable for producing high cell densities of microalgae for accumulation of large quantities of lipids triacylglycerols which can be converted into biodiesel and its growth consumes simple, cheap, and available carbon sources glucose, acetate, glycerol that are commonly used by fermentation industries for other aims, it is predicted that adoption of this approach is an easy, effective commercial implementation of the biodiesel from microalgae strategy. Information concerning the composition of carbohydrates produced by microalgae is also crucial for future applications of microalgae feedstock. conventional, degradation, Microalgae, prokaryotic, eukaryotic, renewable, feedstock, triacylglycerides, trans esterification, Heterotrophic, lipids, biodiesel, fermentation. 775-782 Issue-1 Volume-2 Bhupendra Prasad | Jitendra Malviya | Supriya Maity