Application of Various Microalgal Species for Lipid Production: Biotechnological and Engineering Aspects

Abstract

Lipids derived from algal biomass are important constituents of biofuels, nutraceuticals, cosmeceuticals, and animal feed, inter alia. This necessitates the identification and large-scale production of microalgal species that can serve as the biomass based raw material for the above-mentioned categories of bio-products. In this vein, this review sifts through the literature and describes the most promising microalgal species that synthesize lipids and, when subjected to specific conditions, show enhanced lipid production. Currently, Chlorella sp., Cyclotella sp., Neochloris oleoabundans, and Isochrysis galbana are the species with the highest lipid contents. The review mentions and discusses various bioreactor configurations that can be used for large-scale culturing of these microalgae in a comparative aspect. Various configurations of photobioreactors are suitable for high biomass and lipid productivity. Further, prominent strategies of lipid extraction from microalgae have been elaborated, from conventional techniques to the latest ones, comparing and contrasting their advantages and disadvantages. While solvent-based extractions may have their advantages, it would be prudent to explore more eco-friendly techniques for scale-up. Lastly, the review gives a comprehensive account of the biorefinery approach to culturing microalgae, emphasising the assessment of their economic performance using different software and models, such as the techno-economic assessment model. The application of tools such as multi-criteria decision analysis that assess energy technology could enable better optimization. Microalgae have the potential to be used as a renewable source of fuel and feed; therefore, it is incumbent on the scientific community to significantly reduce production costs while ensuring sustainability.