Mesoporous silica nanoparticles encapsulating xylanase: Efficient platform for low-polymerization-degree xylooligosaccharides preparation

Xylooligosaccharides (XOS) are prebiotic oligosaccharides that can be efficiently produced through enzymatic hydrolysis. Therefore, the oriented control of the degree of polymerization (DP) of oligosaccharides obtained through enzymatic hydrolysis is a crucial research aspect, as oligosaccharides with lower DP exhibit superior biological activity. However, the industrial application of XOS production is limited by the low stability of free xylanase. In this work, mesoporous silica nanoparticles (MSN) were constructed for xylanase immobilization, successfully achieving high yield of XOS with DP of 2 ∼ 6. The recovered activity of Xyl@MSN was 76.85 %, and its residual activity after hydrolysis was 37.7 % higher than that of the free enzyme. Moreover, the conversion rate to xylobiose (X2)- xylohexaose (X6) products reached 66.90 % with Xyl@MSN as catalyst, significantly higher than that of free enzyme (56.03 %). Notably, hydrolysis products using Xyl@MSN as catalyst consisted almost exclusively of X2 and xylotriose (X3). In addition, excellent reusability of Xyl@MSN enables it to retain 41 % of its initial enzymatic activity after being used five reaction cycles with a, high half-life of 462.19 min. Overall, this work not only enables the reuse of the enzyme but also achieves the production of highly active XOS (with nearly 100 % being the X2–X3 fractions), thereby providing new perspectives and technologies for the immobilization of xylanase and the efficient production of XOS.