YEAST LIPIDS EXTRACTION BY SUPERCRITICAL CARBON DIOXIDE AND COSOLVENTS

P. HEGEL; S. CAMY; J.S. CONDORET

Graz

Congreso; 12th European Meeting on Supercritical Fluids: New Perspectives in Supercritical Fluids Materials, Nanoscience and Processing; 2010

Graz University of Technology - ISASF

Saccharomyces cervisiae which is one of the most studied and industrially exploited yeast, is a non-oleaginous yeast whose lipids are mainly phospholipids. In the present work we studied the extraction of yeast lipids by supercritical carbon dioxide (SCCO2) and ethanol as a co-solvent. In particular our attention was focused on the selectivity toward triacylglycerols, and in a subsequent extraction of the phospholipids present in the yeast. Indeed CO2 is a non-polar solvent and by itself is not an efficient solvent for the extraction of phospholipids. However, SCCO2 can be used to extract neutral lipids, as triacylglycerols, and the addition of polar co-solvents like ethanol, at different concentrations, could allow a more efficient extraction of triacylglycerols and also an extraction-fractionation of phospholipids. In this work SCCO2 extractions of S. cervisiae and a membrane complex of this yeast, subjected to different pretreatments, were carried out at 200 bar and temperatures in a range of 40 to 60°C, using different concentrations of ethanol as a co-solvent. The kinetics of the extraction were successfully represented by Sovova?s model. The extraction and fractionation of special lipids with SCO2 and co-solvents from S. cervisiae was studied regarding it as a promising process to the recovery of valuable by-products from yeasts and such kind of process could then be extended to different types of oleaginous yeasts.