Extraction and purification of an endo-1,4-β-xylanase from wheat malt

Abstract

Wheat and wheat malt are known to be high quality raw materials in the beer brewing process. The size and structure of wheat arabinoxylans (AXs) and their enzymatic degradation products have a profound impact on beer properties, such as viscosity, turbidity, filtration rate and foaming properties. AXs are of great benefit to human health due to their anti-tumor properties and potential roles in the immune system. Endo-1,4-β-xylanase is a key enzyme for degradation of AXs and production of small molecule AXs, thereby altering the properties of AXs, such as solubility, viscosity, and turbidity. In this study, extraction and purification of an endo-1,4-β-xylanase from wheat malt was described. The results showed that, after 40%–60% ammonium sulfate precipitation, Q-Sepharose Fast Flow anion exchange chromatography, Phenyl-Sepharose 6 Fast Flow Hydrophobic chromatography, and twice sephacryl S-100 HR gel filtration, a final endo-1,4-β-xylanase was obtained. The purified wheat malt endo-1,4-β-xylanase showed a single band on SDS-PAGE with a molecular weight of 27.8 kDa, which had a purification fold of 12.08 and a specific activity of 4.47 μ/mg.