Cetyl trimethyl ammonium bromide-activated lipase from Aspergillus oryzae immobilized with Cu3(PO4)2•3H2O via biomineralization for hydrolysis of olive oil

Cetyl trimethyl ammonium bromide (CTAB)-activated lipase-mineral hybrid microflowers (CTAB-Lip-MHFs) were fabricated via biomineralization using Cu-3(PO4)(2)center dot 3H(2)O as the mineral for olive oil hydrolysis. FT-IR spectra indicated that immobilized lipase molecules in CTAB-Lip-MHFs has good structural integrity, and XPS spectra revealed that immobilized lipase molecules were present at the surface of CTAB-Lip-MHFs. Kinetic studies suggested that CTAB-Lip-MHFs had good substrate affinity ascribed to interfacial effect caused by CTAB, meanwhile, the open conformation of lipase activated by CTAB contributed to increased reaction rate with substrate. The generated fatty acids via hydrolysis of olive oil by CTAB-Lip-MHFs were 146% of that by free lipase, moreover, CTAB-Lip-MHFs could retain 76.5% and 93.2% of initial activities after storage at 50 degrees C for 10 h and 4 degrees C for 30 days, respectively, indicating the good stability of CTAB-Lip-MHFs. In addition, after 5 recycles, CTAB-Lip-MHFs preserved 72.7% of initial activity, demonstrating the favorable reusability of CTAB-Lip-MHFs for fatty acid production.