Effect of high hydrostatic pressure treatment with room-temperature ionic liquid 1-ethyl-3-methylimidazolium acetate - dimethyl sulfoxide mixture on lipid extraction from Chlorella vulgaris

In this study, Chlorella vulgaris (C. vulgaris) was immersed in a mixture of 1-ethyl-3-methylimidazolium acetate and dimethyl sulfoxide, and treated hydrostatically at 0.1-250 MPa. For the first time, the relationship between the amount of lipids and fatty acids and high hydrostatic pressure was investigated, as well as the relationship between the amount of fatty acids and the morphology of C. vulgaris cells after treatment. We found that the amount of lipids was maximized and the amount of fatty acids extracted was significantly higher following treatment at 50 MPa than at ambient pressure. The purity of the extracted fatty acids (the amount of fatty acids contained in the extracted lipids) was high following treatment at 200 and 250 MPa, and was about double that of the amount of fatty acids obtained using the Bligh & Dyer and Soxhlet extraction methods, which are typically used for lipid extraction.