Efficient lipid extraction and quantification of fatty acids from algal biomass using accelerated solvent extraction (ASE)

Accelerated solvent extraction (ASE), a commercially available pressurized fluid extraction technique and conventional manual extraction were compared to identify the most effective chloroform-methanol extraction method for algal lipids. Using optimal ASE operating conditions (methanol/chloroform = 2 : 1 by vol, 100 degrees C, static time of 5 min, and four static cycles), the lipid contents of Chlorella vulgaris, C. sorokiniana, C. zofingiensis and Nannochloropsis gaditana were 27.5%, 25.8%, 15.2%, 29.8% of dry biomass, respectively. The total fatty acid methyl ester (FAME) content of dry biomass from ASE extraction was found to be 1.3-2.7 fold higher than that from conventional manual extract from these species, demonstrating that ASE exhibited significant improvement for lipid and FAME recovery. Furthermore, ASE showed the capacity to extract all-cis-5,8,11,14,17-eicosapentaenoic acid (EPA) as 3.0% of dry biomass from Nannochloropsis gaditana suggesting that ASE has the potential to obtain polyunsaturated fatty acids (PUFAs) as well.