Waste cooking oils: Low-cost substrate for co-production of lipase and microbial lipids

Abstract

Waste Cooking Oils (WCO), generated from vegetable oils used at high temperatures in food frying, represent a highly dangerous threat to the environment. The ability of Y. lipolytica to grow and simultaneously produce lipase and accumulate lipids on this cheap and renewable carbon source was evaluated. A statistical experimental design based on Taguchi method was employed to assess the individual and combined effect of pH, WCO concentration and arabic gum concentration on lipase and microbial lipids production. pH was found to be the most significant parameter and the interaction between WCO and arabic gum concentration had the higher influence for both lipase and microbial lipids production. The scale-up of the process in a 2-L bioreactor demonstrate that oxygen concentration was also a crucial parameter to consider for lipase production. Increasing oxygen availability, a 38-fold improvement in lipase activity was achieved.