Sulaiman Al‐Zuhair

Despite the increasing interest in biodiesel production from microalgae, the high cost of multistage production processes still hinders its commercialization. The high oil productivity of microalgae and their ability to grow rapidly under harsh conditions and in saline water make them a favorable feedstock for biodiesel production. In this review, conventional methods of producing biodiesel from microalgae are thoroughly discussed and compared to state‐of‐the‐art technologies. Considerable emphasis has been put on the adoption of biocatalysts as alternative greener and more effective catalysts. Challenges facing the biocatalytic process and innovative ways to overcome them are also presented. The main focus is on the in‐situ biodiesel production processes, which are promising to pave the way for industrial application of microalgae‐to‐biodiesel process. The use of state‐of the‐art thermoresponsive switchable solvents, coupled with immobilized lipase, for simultaneous cell disruption, oil extraction‐reaction, and product separation in one pot has shown to be highly favorable. Because enzymes are expensive, finding ways to enhance their stability and reusability for a greater number of cycles is essential for the process to be economically viable and competitive.