مشخصات پژوهش

Background: The vegetable oil refinery wastewater (VORW) ‎is an environmental pollutant ‎in developing countries which produce 75% of annually worldwide of vegetable oils. ‎Microbial oils are considered for the production of renewable biofuel feedstocks, food and ‎feed supplements ‎from low-cost substrates. In the current study, VORW as a cheap substrate ‎and environmental pollutant was used to produce added-value compounds like lipase, ‎microbial oil and lipid-rich biomass by Yarrowia lipolytica. The COD reduction of the ‎wastewater was studied after fermentation. ‎ Results: The maximum microbial oil ‎concentration and lipase activity were 2.68 g/L and 8 ‎U/mL after 48 h of inoculation. The microbial oil production from 2.86 g/L was reached to ‎‎7.74 g/L after optimization by response surface methodology. 11 g/L of microbial oil and ‎‎18.3 g/L of biomass were obtained in bioreactor culture containing optimized medium. The ‎amount of unsaturated fatty acids was reached up to 63% in the resulting microbial oil with ‎a suitable‏ ‏fatty acid profile for the production of lipid-rich biomass. The biomass of Y. ‎lipolytica has 60% lipid content and ‎a significant amount of essential fatty acids which ‎makes it as a proper feed supplement. The COD level of the wastewater was decreased by ‎‎80% after 20 h. ‎ Conclusion: VORW can be used as a promising substrate for sustainable production of ‎microbial oil and lipid-rich biomass with useful fatty acids by Y. lipolytica as well as ‎environmental pollution of the wastewater is reduced simultaneously in a safe and eco-‎friendly way.‎