Octadecanoic acid/silica particles synthesis for enzyme immobilization: Characterization and evaluation of biocatalytic activity

Water insoluble enzyme particles (WIEP) were prepared by first anchoring the octadecanoic acid over porous silica particles (OAS) followed by diastase enzyme binding. These particles were characterized using FT-IR, X-ray crystallography and X-ray photoelectron spectroscopy (XPS) and evaluated for starch hydrolysis activity. The results indicated that the enzyme binding to OAS particles was dependent on pH and temperature of the medium. Maximum enzyme binding (>48%) to OAS particles was observed at pH 3 and at 30 °C, while highest biocatalytic activity of WIEP was observed at pH 4 and at 40 °C. The storage stability study of water insoluble enzyme particles was evaluated for more than 70 days without any enzyme activity loss.