Abstract
Rapid population growth globally and urbanization have caused a significant drop in fossil fuel feedstocks, pushing countries to seek alternative sources. Microalgae are a feasible biofuel feedstock due to their high photosynthetic efficiency, which gives various potential benefits for the environmentally friendly biofuel production process, besides the high biomass productivity strains required for a longterm integrated platform. Consequently, modifying lipid metabolic pathways to increase lipid production in microalgae cells consider a viable strategy. Overexpression and transformation of key genes involved in lipid biosynthesis are regarded to be crucial methods for increasing lipid production. Whereas transformation and gene editing are two approaches affecting these alterations, that have been sufficiently established in microalgae, transforming these strains into a very adaptive stage for successfully designing ways to produce biofuel. The current mini-review focuses on potential strategies for improving microalgae metabolic engineering, specifically lipogenesis, by regulated overexpression of native genes or transgenes such as acetyl coenzyme-A carboxylase, diacylglycerol acyltransferase, and malic enzyme genes, as well as current limitations and gaps and future directions.