Fabrication of Aspergillus oryzae lipase-immobilized magnetic Cu3(PO4)2∙3H2O nanoflowers for efficient synthesis of structured phospholipids

Abstract

To synthesize structured phospholipids (SPLs) in an efficient and green manner is of great significance. Herein, novel Fe3O4@SiO2-Aspergillus oryzae lipase (AOL)/copper phosphate trihydrate nanoflowers (FLCNs) were prepared by coprecipitation method and then characterized by energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometer etc. FLCN activity was further evaluated by promoting functional medium-chain SPL (MCSPL) or short-chain SPL (SCSPL) synthesis via biotransesterification between soybean lecithins and medium-chain fatty acids (MCFAs) or short-chain fatty acids (SCFAs) under optimal reaction conditions. Moreover, FLCNs and free AOLs were comparatively assayed in enzymatic properties. As a result, FLCNs were successfully fabricated with sufficiently large surfaces and numerous enzyme active sites. Owing to these structural features, after reacting at 40 °C for 36 h with FLCN dosage of 6% and substrate mass ratio of 1:3:3, FLCNs exhibited much more excellent activity in MCSPL synthesis with 88.30 ± 0.63% of MCFA incorporation than benchmark enzymes and heterogeneous functional materials. Most significantly, in the first biosynthesis of functional SCSPLs facilitated by FLCNs, much superior SCFA incorporation of 66.55 ± 0.73% was obtained. Notably, FLCNs also possessed convenient magnetic separability together with superior pH and temperature tolerances, thermal and storage stabilities, and recyclability to free AOLs. In brief, the present investigation provides a new biological strategy for effective, economic, convenient, and eco-friendly SPL synthesis in food and pharmaceutical industries, highlighting its merits in functional lipid production.