Abstract:In this study, the extraction technology and enzymatic property of xylanase produced from engineered Escherichia coli are fully examined. The extraction of production process of xylanase was determined and the forage enteric xylanase was successfully obtained after cell broken (high-speed ball grinding), solid-liquid separation, aseptic (filtering) hollow fiber membrane, ultrafiltration concentra-tion and drying packaging orderly. This production showed desirable thermal stability and its release rate was 5% and 98.5% in pH 2.5 and pH 5.5 phosphate buffer, respectively. The product appearance exhibited good gloss and it could meet the requirements of feed enzyme market well. The xylanase showed the maximal activity at pH 6.4 and 55 ℃, and xylanase with 17% water content just lost 13.6% activity at 90 ℃ after dealing with for 2.5 min. By measuring the oat spelt xylan degradation products, the enzyme was revealed to be a kind of Endo-xylanase.