Abstract
Microalgal lipid is a major natural feedstock for biodiesel production. However, microalgae-based biofuel technology comes with obstacles to production, such as high investment and operating costs. To overcome these problems, nowadays some strategies have been used during cultivation stage of the microalgae for enhancing biomass and accumulate lipids and carbohydrates which could be used for biofuel production. The most common methods applied to microalgae are classified as nutrient stress and changes in growth conditions that lead to increase the lipid content in the species without decreasing the growth rate of their potential strains or by simultaneously increasing both of these. Scenedesmus sp. are considered to be the most appropriate microalgae to culture commercially due to their high biomass, lipid and carbohydrate yield. The purpose of this review was to describe nutrient stress strategy to develop biofuels as a sustainable alternative to fossil fuels and, in particular, with respect to nitrogen nutrient limitations, the lipid yield and biomass development in Scenedesmus sp. microalgae. The nitrogen starvation/limitation strategy that will increase the general economic feasibility of microalgal lipid production and affect the fatty acid composition was presented.