Lipid extraction from Yarrowia lipolytica biomass using high-pressure homogenization

This work aims at investigating the impact of high-pressure homogenization (HPH) for oil recovery from Yarrowia lipolytica yeast. First, HPH parameters (pressure and number of passes) were optimized, by measuring the disintegration index and the release of ions, proteins, and nucleic acids during the HPH pre-treatment. Results obtained showed that 1500 bar and 5 passes allowed the maximum cell disruption, and total oil recovery in dry route (lyophilization and n-hexane extraction). HPH-treated cells were then extracted in wet route by directly adding n-hexane (without drying) and mixing using a high-speed disperser. Different ratios and extraction times were tested in order to optimize the extraction parameters. Maximum oil recovery in wet route was ≈80%, obtained using 40 min extraction, a rotation speed of 10000 rpm, and a HPH-treated suspension:n-hexane ratio of 1:2. Microscopy pictures, granulometry, and Peleg's model exploitation supported the results obtained in this work.