Microalgal biofuel production: Potential challenges and prospective research

•Contemporary microalgal cultivation techniques for biofuel production were summarized.•Numerous microalgae biofuel options and their conversion technologies were discussed.•Metabolic engineering is a legitimate strategy for regulating microalgal components for biofuel generation.•Research challenges in commercializing microalgal biotechnology were highlighted. Exponential growth in industrialization can be seen as a direct outcome of the urbanization which results in the continuous depletion of natural energy reserves. The existence of carbon dioxide in the ecosystem is primarily due to the fossil fuel combustion from the variety of energy-driven vehicles. Hence, to reduce its levels in the atmosphere and to prevent the depletion of non-renewable resources, scientific researchers have made significant attempts to provide alternate and sustainable ways of producing energy. One such noteworthy effort is the biofuel production from the microalgae that has an excellent potential in lipid accumulation and bioconversion. Despite numerous reports are available on the effective biofuel production, the process scaling-up and its commercialization remains in vain. Hence, the present review is intended to critically identify the possible gaps in the current research and to provide potential challenges to be scientifically addressed in the prospective research of biofuel production.