Chemoenzymatic synthesis of fluorogenic phospholipids and evaluation in assays of phospholipases A, C and D

Application of Magnetic Nano-Immobilized Enzyme in Soybean Oil Degumming: Numerical Simulation in a Liquid-Solid MFB

Using crude soybean oil (CSO) as fluid and nanomagnetic immobilized phospholipase C (PLC) as fluidizing particles, the Eulerian–Lagrangian fluid-particle two-phase flow model was used to numerically simulate the law of motion of fluidizing particles in the magnetic fluidized bed (MFB). The main parameters were obtained by numerical simulation based on the discrete element method (DEM). The nanomagnetic PLC in the MFB was optimal to the enzymatic reaction by limiting the iteration step size to 3 × 10−5, the boundary condition to 20 × 300 mm, the opening rate to 37.5%, the condition of CSO flow rate to 0.01 m/s, and the magnetic field strength to 0.02T. After 2.0 h of reaction, the amount of residual phosphorus in the oil was 55.73 mg/kg, the content of 1, 2-DAG was 1.42%, and the nanomagnetic enzyme still had 97% relative activity. Hence, these optimal conditions can improve the efficiency and the stability of the nanomagnetic enzymatic reaction.

Stabilization of Lecitase Ultra® by Immobilization and Fixation of Bimolecular Aggregates. Release of Omega-3 Fatty Acids by Enzymatic Hydrolysis of Krill Oil

Lecitase Ultra® solutions are mainly composed of bimolecular aggregates of two open structures of the enzyme. The immobilization and fixation of these bimolecular aggregates onto support surfaces is here proposed as a novel protocol for the immobilization and stabilization of Lecitase. The resulting derivatives of Lecitase aggregates were much more stable than the diluted solutions of the enzyme. The most stable of them was obtained by covalent immobilization of the bimolecular aggregate: 300-fold more stable than the diluted enzyme and 75-fold more stable than open Lecitase adsorbed onto hydrophobic supports. The bimolecular aggregate that adsorbed onto polyethyleneimine-agarose exhibited the best combination of activity and stability for the hydrolysis of krill oil. Omega-3 acids are in the sn-2 position of the krill oil, but they are also released by a phospholipase A1 because of migration issues.

Synthesis and Application of Nanomagnetic Immobilized Phospholipase C

The nanomagnetic carrier (Fe3O4@SiO2@p(GMA)) was prepared by atom transfer radical polymerization, and then, the free phospholipase C (PLC) was immobilized on it proved by the results of FT-IR analysis. The enzyme loading was 135.64 mg/g, the enzyme activity was 8560.7 U/g, the average particle size was 99.86 ± 0.80 nm, and the specific saturation magnetization was 16.00 ± 0.20 emu/g. PLC-Fe3O4@SiO2@p(GMA) showed the highest activities at the pH of 7.5, and tolerance temperature raised to 65°C in soybean lecithin emulsion. Enzymatic degumming with PLC-Fe3O4@SiO2@p(GMA) under the conditions of the enzyme dosage of 110 mg/kg, reaction temperature of 65°C, pH of 7.5, and reaction time of 2.5 h resulted in residual phosphorus of 64.7 mg/kg, 1,2-diacylglycerol (1,2-DAG) contents of 1.07%, and oil yield of 98.1%. Moreover, PLC-Fe3O4@SiO2@p(GMA) still possessed more than 80% of its initial activity after 5 cycles.