LAUSR

Abstract In this study, a novel support (Phenyl–SiO2) has been prepared via functionalization of rice husk silica (RHS) with triethoxy(phenyl)silane. For such a purpose, the functionalized support was used to immobilize lipase from Thermomyces lanuginosus (TLL) by physical adsorption via hydrophobic interactions. Introduction of phenyl groups on the support surface has been confirmed by SEM, TEM, AFM, B.E.T. and elemental analysis. Maximum immobilized protein concentration of 27.7 ± 2.3 mg/g was achieved using an initial protein loading of 40 mg/g. The catalytic activity of the prepared biocatalyst was assayed by olive oil emulsion hydrolysis, thus resulting in 655.6 ± 31.9 U/g. It was also used as biocatalyst to synthesize cetyl oleate, an important long-chain alkyl ester with emollient properties, via direct esterification in a solvent-free system. Maximum conversion of 92% after 330 min of reaction has been observed. Moreover, it fully retained its initial activity after seven successive batches. These results demonstrate that RHS functionalization is an effective strategy to prepare an active and stable biocatalyst for the synthesis of cosmetic ester.