Structural characterization of MAPLE deposited lipase biofilm

tLipases (triacylglycerol ester hydrolases) are enzymes used in several industrial applications. Enzymesimmobilization can be used to address key issues limiting widespread application at industrial level.Immobilization efficiency is related to the ability to preserve the native conformation of the enzyme.MAPLE (Matrix Assisted Pulsed Laser Evaporation) technique, a laser deposition procedure for treatingorganic/polymeric/biomaterials, was applied for the deposition of lipase enzyme in an ice matrix, usingnear infrared laser radiation. Microscopy analysis showed that the deposition occurred in micromet-ric and submicrometric clusters with a wide size distribution. AFM imaging showed that inter-clusterregions are uniformly covered with smaller aggregates of nanometric size. Fourier transform infraredspectroscopy was used for both recognizing the deposited material and analyzing its secondary structure.Results showed that the protein underwent reversible self-association during the deposition process.Actually, preliminary tests of MAPLE deposited lipase used for soybean oil transesterification withisopropyl alcohol followed by gas chromatography-mass spectrometry gave results consistent withundamaged deposition of lipase.