A recent update on enhancing lipid and carbohydrate accumulation for sustainable biofuel production in microalgal biomass

Abstract In our world of ever-growing energy demand, it is important to look for other suitable and sustainable fuel sources. Biofuels are a renewable and sustainable source of fuel produced from biological sources. In this direction, using microalgal biomass as a sustainable feedstock to produce biofuels has many advantages including their easy and economical cultivation. However, a major drawback of using microalgae as the fuel source is the biomass yield vis-à-vis their lipid and carbohydrate profile. This review targets the different techniques used to enhance the accumulation of lipids and carbohydrates in the microalgal cells which in turn increase the yield of biodiesel and bioethanol respectively. An extensive survey led to the identification of diverse factors that significantly influence the enhancement of lipids and carbohydrates. The current review explores the effect of such parameters that include physical parameters (temperature, pH, light intensity, etc.), nutrient stress (macro/micronutrient modification, etc.), and other methods like genetic modifications. It also addresses how incorporating nanoparticles into different stages of biofuel production leads to enhanced bioethanol and biodiesel yields.