Nanomaterials in Lignocellulosic Biodiesel Production by Oleaginous Microorganisms

Abstract

Biodiesel is considered an alternative to fuel, which is primarily obtained from plant-based oils and animal fats. However, the land area requirement for cultivation of nonedible energy crops and food security concerns over the usage of edible oils entails the use of alternative feedstocks for biodiesel production. The lignocellulosic biomass (LCB) such as rice straw, wheat straw, sugarcane bagasse, and deoiled algal residue are rich sources of cellulosic and hemicellulosic sugars that can be converted into microbial lipids by oleaginous microorganisms. Consequently, microbial lipids may be a potential substitute forplant-based oils in biodiesel production. However, the recalcitrance of LCB necessitates prior pretreatment. Besides, the cultivation condition for high lipid titers and the efficiency of transesterification reaction determine the economic feasibility of the process. Nanomaterials find wide applications in bioenergy as an immobilization matrix, culture media additives, or carriers of specific ingredients and functionalized nanomaterials as solvent emulsifiers. In this chapter, we have discussed the applications of nanobiomaterials in pretreatment and enzymatic hydrolysis of LCB, induction of various stress conditions in culture media for enhanced lipid accumulation by oleaginous microbes, cell wall disruption, extraction of lipids and natural pigments, and development of renewable catalysts for transesterification of microbial oil into biodiesel.