Zeolite-based nanocomposite as a smart pH-sensitive nanovehicle for release of xylanase as poultry feed supplement

Abstract

Xylanase improves poultry nutrition by degrading xylan in the cell walls of feed grains and release the entrapped nutrients. However, the application of xylanase as a feed supplement is restricted to its low stability in the environment and gastrointestinal (GI) tract of poultry. To overcome these obstacles, Zeozyme NPs as a smart pH-responsive nanosystem was designed based on xylanase immobilization on zeolitic nanoporous as the major cornerstone that was modified with L-lysine. The immobilized xylanase was followed by encapsulating with a cross-linked CMC-based polymer. Zeozyme NPs was structurally characterized using TEM, SEM, AFM, DLS, TGA and nitrogen adsorption/desorption isotherms at liquid nitrogen temperature. The stability of Zeozyme NPs was evaluated at different temperatures, pH, and in the presence of proteases. Additionally, the release pattern of xylanase was investigated at a digestion model mimicking the GI tract. Xylanase was released selectively at the duodenum and ileum (pH 6–7.1) and remarkably preserved at pH ≤ 6 including proventriculus, gizzard, and crop (pH 1.6–5). The results confirmed that the zeolite equipped with the CMC matrix could enhance the xylanase thermal and pH stability and preserve its activity in the presence of proteases. Moreover, Zeozyme NPs exhibited a smart pH-dependent release of xylanase in an in vitro simulated GI tract.

Improving the saccharification efficiency of lignocellulosic biomass using a bio-inspired two-stage microreactor system loaded with complex enzymes

“…Specifically, in the pH range of 3.5 to 5.5, the relative activity of free and immobilized xylanase increased first and then decreased, and their optimal pH values were both 5.0. Although the changes in enzyme conformation at too high or low pH values would negatively affect the enzyme activity, 34 the relative activity of immobilized xylanase was slightly higher than that of free xylanase at most pH values. At an acidic pH value of 3.5, the relative activity of the microreactor loaded with xylanase was 17.0% higher than that of free xylanase.…”