Interfacial modulation of hierarchically porous UIO-66 for the immobilization of Rhizomucor miehei lipase towards the efficient synthesis of 1,3-dioleic acid glycerol

Herein, UiO-66 was selected as the immobilization carrier of Rhizomucor miehei lipase (RML). After etching and hydrophobic modification, the functionalized UIO-66 (H-UIO-66-OPA) was utilized for RML immobilization and the obtained RML@H-UIO-66-OPA showed about 70 % relative activity after incubation at 60 °C, which was much better than RML (20 %). RML@H-UIO-66-OPA was used in the synthesis of 1,3-dioleic acid glycerol (1,3-DAG) and the effects of reaction conditions (temperature, enzyme addition, substrate molar ratio, and time) on 1,3-DAG yield were investigated. Under the optimal conditions (temperature of 65 °C, enzyme addition of 2 wt%, substrate molar ratio of 2:1, and reaction time of 4 h), 1,3-DAG yield reached 77 %. Finally, Box-Behnken experimental design method was utilized to optimize the process parameters for the preparation of 1,3-DAG, and the final 1,3-DAG content was 79.80 %, which demonstrated that the model could predict the relationship between the factors and be suitable for the process optimization in 1,3-DAG preparation.