Immobilized lipase for sustainable hydrolysis of acidified oil to produce fatty acid

Acidified oil is obtained from by-product of crops oil refining industry, which is considered as a low-cost material for fatty acid production. Hydrolysis of acidified oil by lipase catalysis for producing fatty acid is a sustainable and efficient bioprocess that is an alternative of continuous countercurrent hydrolysis. In this study, lipase from Candida rugosa (CRL) was immobilized on magnetic Fe 3 O 4 @SiO 2 via covalent binding strategy for highly efficient hydrolysis of acidified soybean oil. FTIR, XRD, SEM and VSM were used to characterize the immobilized lipase (Fe 3 O 4 @SiO 2 -CRL). The enzyme properties of the Fe 3 O 4 @SiO 2 -CRL were determined. Fe 3 O 4 @SiO 2 -CRL was used to catalyze the hydrolysis of acidified soybean oil to produce fatty acids. Catalytic reaction conditions were studied, including amount of catalyst, reaction time, and water/oil ratio. The results of optimization indicated that the hydrolysis rate reached 98% under 10 wt.% (oil) of catalyst, 3:1 (v/v) of water/oil ratio, and 313 K after 12 h. After 5 cycles, the hydrolysis activity of Fe 3 O 4 @SiO 2 -CRL remained 55%. Preparation of fatty acids from high-acid-value by-products through biosystem shows great industrial potential. Graphical abstract