Immobilization of enzymatic extract from Penicillium camemberti with lipoxygenase activity onto a hybrid layered double hydroxide

A Zn/Al layered double hydroxide was synthesized by alkaline co-precipitation with azelate ions (−OOC(CH2)7COO−). The interlayer space of the layered material is occupied by organic ions as confirmed by X-ray diffraction and FTIR spectroscopy. The resulting hybrid material was tested as support for Penicillium camemberti enzymatic extract, containing lipoxygenase (LOX) activity. The optimal condition for LOX immobilization is done with 0.6 mol L−1 potassium phosphate buffer and pH 6.0. The affinity for the substrate is the same after immobilization, however the specific activity slightly decreases. The immobilization enhanced the thermal stability, which was evident with incubation at 60 °C where the immobilized enzyme retains 68% of specific activity while the free enzyme is inhibited. Recycling assays showed that after eight reaction cycles, the immobilized enzyme retains 60% of the activity.