Multifarious extraction methodologies for ameliorating lipid recovery from algae.

Amongst the current alternatives, algae were proven to be a promising source of biofuel, which is renewable and capable of meeting world demand for transportation fuels. However, a suitable lipid extraction method that efficiently releases the lipids from different algal strains remains a bottleneck. The multifarious pretreatment methods are prevalent in this field of lipid extraction, and therefore, this article has critically reviewed the various lipid extraction methods for ameliorating the lipid yield from algae, irrespective of the strains/species. Physical, mechanical, and chemical are the different types of pretreatment methods. In this review, methodologies such as homogenization, sonication, Soxhlet extraction, microwave treatment, and bead-beating, have been studied in detail and are the most commonly used methods for lipid extraction. Specific advanced/emerging processes such as supercritical CO 2 extraction, ionic liquid, and CO 2 switchable solvent-based algal lipid extraction are yet to be demonstrated at pilot-scale, though promising. The extraction of lipids has to be financially conducive, environmentally sustainable, and industrially applicable for further conversion into biodiesel. Hence, this paper discusses variable pretreatment for lipid extraction and imparts a comparative analysis to elect an efficient, economically sound lipid extraction method for pilot-scale biodiesel production. • Multifarious pretreatment methods for algal lipid extraction were reviewed. • Conventional methods like sonication, microwave, homogenization was discussed. • Chemical/solvent-based processes for various algal strains were critically analyzed. • Ionic liquids and CO 2 switchable solvent based algal lipid extraction was addressed. • Advances and mechanism in supercritical CO 2 extraction process was presented in-detail. [ABSTRACT FROM AUTHOR]