Engineering strategies and opportunities of next generation biofuel from microalgae: A perspective review on the potential bioenergy feedstock

The quest for alternate fuels that demonstrate reduced environmental impact is ever-increasing. This necessity has been a direct result of the environmental changes that are caused by the usage of fossil fuels. In this regard, sugar cane, corn and soybeans have been employed to make the first-generation biofuels. Second-generation biofuels, made from lignocellulosic crops and forest leftovers, require a lot of land that could have otherwise been utilized for food processing and productions. In this scenario, going by the technical forecasts, microalgae can potentially serve as the primary source for the third-generation of biofuels. By virtue of possessing no such limitations, microalgae are currently viewed as an effective alternative to first- and second-generation biofuels. The goal of this review is to highlight the most effective opportunities for biofuels production using algal sources. In doing so, this review also explains how the chemical compositions of micro and macroalgae, as well as the associated bioactive compounds, render positive influence on biofuel production. In addition to the present review critical discussions have been done on: (a) various growing strategies for rapid cultivation of micro and macroalgae for biomass development, (b) how algal-based ingredients and bioactive compounds are yet unexploited for bioenergy generation, and (c) why algal source and their biomass are regarded as possible bioenergy sources for future green and sustainable energy.