(748b) Cell Lysis and Lipid Recovery from Oleaginous Yeast

Single-cell oils, or lipids derived from oleaginous microbes, have seen recent interest as a potential renewable source of transportation fuels. However, one of the main technical challenges involved in single-cell-oil-derived products is due to the intracellular nature of the oils: the microbial cells must be lysed and the lipids extracted from the resulting complex matrix. We have screened several approaches for cell lysis approaches using the oleaginous yeast Lipomyces starkeyi, and have found that a dilute acid pretreatment compares favorably to a number of alternative strategies including high-pressure homogenization, alkaline pretreatment, bead beating, enzymatic hydrolysis or thermolytic approaches. Extraction of the lysed cells with hexane allows for recovery of the lipids in yields above 90% and in high purity. The acid pretreatment is also effective on strains of Cryptococcus curvatus and Rhodosporidium toruloides, and is highly scalable.