Lipid yield from the diatom Porosira glacialis is determined by solvent choice and number of extractions, independent of cell disruption

Abstract

AbstractCell wall disruption is necessary to maximize lipid extraction yields in conventional species of mass-cultivated microalgae. This study investigated the effect of sonication, solvent choice and number of extractions on the lipid yield, lipid class composition and fatty acid composition of the diatomPorosira glacialis.For comparison, the diatomOdontella auritaand green algaChlorella vulgariswere included in the study.Sonication effectively disruptedP. glacialiscells, but did not increase the total lipid yield compared to physical stirring (mixing). In all three microalgae, the content of membrane-associated glyco- and phosopholipids in the extracted lipids was strongly dependent on the solvent polarity. A second extraction resulted in higher yields from the microalgae only when polar solvents were used. In conclusion, choice of solvent and number of extractions were the main factors that determined lipid yield and lipid class composition inP. glacialis.