Lipase production by Yarrowia lipolytica using olive oil processing wastes as substrates

In this study solid and liquid wastes from the olive oil processing industry were evaluated as substrates for Yarrowia lipolytica growth with the aim of lipase production. Olive mill wastewater and olive oil cake seemed to provide necessary nutrients and physical support for the yeast to grow and produce enzyme. The highest lipolytic activity of 850 IU dm-3 was achieved after 4 days of submerged cultivation in supplemented olive mill wastewater. In addition, olive oil cake appeared to be a convenient substrate for lipase production under solid state fermentation mode. Lipase production was further improved by media supplementation and/or change in physical settings of the experiment. However, the most significant improvement of lipase production under solid state fermentation was achieved by an alkaline treatment of the substrate (more than 10-fold) when the amount of produced lipase reached up to ~40 IU g-1 of substrate.