Immobilization of Candida antarctica Lipase B on Silicone Nanofilaments

Abstract

Candida antarctica lipase B was immobilized on a series of silicone nanofilament-coated matrices of different porosities. In addition to creating a more open surface, SNF’s hydrophobicity allows for a simple immobilization pathway via adsorption. In order to study the impact of the nanostructure, the performance was compared with control samples lacking SNFs. For all materials, the surface was characterized with BET measurements, and the immobilized enzyme was measured as well as the catalytic activity. Enzyme loads ranged between 3.85% $w/w$ and 2.53% $w/w$ and decreased with the decreasing surface area of the carrier material from 200 m2/g to 0.04 m2/g, while the activity per enzyme increases from 824 U to 2040 U. The data suggest that the coating seals off inner surfaces, forcing the enzyme to be immobilized at more accessible positions allowing for higher activity per enzyme. Optimization of the immobilization conditions allowed us to create a thinner enzyme layer which further improved the activity per enzyme to 3129 U. While this activity is comparable to the commercial Novozyme 435 with 3073 U, the SNF-based system performs the catalysis in a thin surface layer of around 13 μm. A favorite area of application is, for example, the creation of enzyme-based detection systems, where the high activity per surface area of up to 89622 U $·$ mg/m2 would lead to high signal strength.