Adsorption of tannase from Aspergillus ficuum to carboxyl-functionalized multi-walled carbon nanotubes Scientific paper

Abstract

The immobilization of cross-linked tannase onto carboxyl-function­alized multi-walled carbon nanotubes (MWCNT-COOH) was achieved via physical adsorption. Glutaraldehyde was used to cross-link the enzyme mole­cules. Spectroscopic and morphological characterizations of the enzyme-nano­tubes composite were carried out, which authenticated the successful adsorpt­ion event. Enzyme composite is proven equal to, or even superior than free tannase, in terms of catalytic activities and stabilities, when measured under different thermal, pH and recycling conditions. Whilst both free and immo­bilized tannase preparations exhibited optimum catalysis at pH 5.0 and 35 °C, tannase-nanotubes composite possesses better thermal stability. The immobil­ized preparation retained 75 % of its initial catalytic activity following ten con­secutive uses. The study demonstrated a facile method to produce catalytically efficient nanobiocatalyst composite for biotechnological applications.