A new bioremediation method for removal of wastewater containing oils with high oleic acid composition: Acinetobacter haemolyticus lipase immobilized on eggshell membrane with improved stabilities

Abstract

As a result of the increasing demand for edible oils, which are an important part of human nutrition, in recent years, serious environmental problems may arise both during the production and after consumption of these oils. One of these problems is the removal of oily wastewater formed by mixing these oils with water. In this study, lipase enzyme produced by Acinetobacter haemolyticus was immobilized onto eggshell membrane (ESM) using adsorption and cross-linking methods, and optimization and characterization studies of lipase immobilization were performed. ESM and lipase immobilized ESM were characterized by Fourier Transform Infrared (FTIR) Spectroscopy and Scanning Electron Microscopy (SEM). At 50 °C, 60 °C and 70 °C, the immobilized enzyme retained 50% of its activity for 150, 120 and 80 min, respectively. In pH stability experiments, the immobilized enzyme showed much higher activity, especially in the acidic region, compared to the free enzyme. The immobilized enzyme managed to preserve approximately 50% of its activity after 19 reuses. As a result, it can be said that a new, economical, reusable and alternative bioremediation method has been developed by using lipase immobilized ESM in the treatment of wastewater containing oils with high oleic acid composition.