Perspectives on metabolic engineering for increased lipid contents in microalgae

With increasing concerns about the world's crude oil consumption, alternative fuels based on renewable resources attract more and more attention. Microalgae have been proposed to be one of the most sustainable feedstocks for the production of lipid-based biodiesel. Naturally occurring, high-lipid producing microalgae strains can be domesticated and further genetically improved in order to redirect metabolite fluxes towards increased lipid contents. This review summarizes the current knowledge about metabolic engineering of microalgae in order to increase the cellular lipid content, with an emphasis on triacylglycerols for the production of biofuels. Additionally, it outlines the contribution of systems biology and genome-scale metabolic pathway modeling, as well as their potential impact in the future.