Modificação de sílica gel com octiltrietoxisilano para imobilização da lipase Eversa® transform 2.0.

Abstract

Enzymes play a crucial role in industry, and among them, the most prominent are lipases (EC 3.1.1.3) triglyceride hydrolases applied in various processes. However, they have limitations in their use in their soluble forms. One way to get around this is through the immobilization process, which in addition to increasing their stability under operational conditions, also allows their reuse. Immobilization on hydrophobic supports is shown to be an efficient alternative, as it allows the immobilization of the lipase in its most active conformation, favoring the interface activation mechanism and being able to significantly increase its hydrolytic activity. In this context, the main objective of this study was to produce a hydrophobic support for subsequent immobilization of the lipase Eversa® Transform 2.0 (LE) by adsorption via interface activation. The production of hydrophobic supports was carried out from silica gel functionalized with octyltriethoxysilane (OTEOS). The process was carried out at three different temperatures to evaluate whether the temperature influenced the formation of octyl-silica. After the production of the material, the immobilization of lipase Eversa was performed, whose enzymatic activity was quantified by the hydrolysis of p-nitrophenyl butyrate (pNPB). The biocatalysts were evaluated for hydrolytic activity, thermal and operational stability, desorption and the immobilizations were recorded by Fourier Transform Infrared Spectroscopy (FTIR). The best synthesized biocatalyst was lipase Eversa immobilized in octylsilica prepared at 25°C (OC-SILICA-25-LE). This biocatalyst presented an immobilization yield of 94.16 ± 0.12% in 1 hour and recovered activity of 53.49 ± 5.26%. Furthermore, the OC-SILICA-25-LE biocatalyst was 418.6 times more stable when compared to soluble Eversa lipase. Regarding operational stability, OC-SILICA-25-LE found its activity to be around 72% after 7 cycles of pNPB hydrolysis.