青霉L1来源具有生产木寡糖应用潜力的高比活GH11木聚糖酶  

A highly active GH11 xylanase from Penicillium sp.L1 with potential applications in xylo-oligosaccharide production

作　　者：王晓宇[1] 刘伟娜 谢响明[1] 姚斌[2] 罗会颖[2] 

机构地区：[1]北京林业大学生物科学与技术学院,北京100083 [2]中国农业科学院饲料研究所,北京100081

出　　处：《生物工程学报》2018年第1期68-77,共10页Chinese Journal of Biotechnology

基　　金：国家自然科学基金(No.31472127)资助~~

摘　　要：木聚糖酶是一种备受关注的糖苷水解酶,能够应用于酿造、饲料、制药、生物能源等多个领域,但是目前大部分木聚糖酶在低于30℃的环境中活力较低。为了获得在较低温度下具有高活力的木聚糖酶,从青霉L1(Penicilliumsp.L1)中克隆到一条GH11木聚糖酶基因XYN11A,并在毕赤酵母GS115中进行异源表达。经过纯化和酶学性质测定,该酶的最适p H和最适温度分别为3.5-4.0和55℃,能够在酸性和中性缓冲液(p H 1.0-7.0)中以及40℃下保持稳定,同时对所有已测试的金属离子和化合物都有一定的抗性。值得注意的是,该酶具有GH11家族中比较高的比活力6 700 U/mg,另外,该酶在较低温度20-40℃亦可展现出较高的酶活力(24%-58%)。经过16 h的榉木木聚糖水解实验,该木聚糖酶的水解产物主要是木二糖、木三糖和木四糖,几乎不产生单体木糖。因该酶同时具有产寡糖、较低温度下活力高以及嗜酸性等3种特性,XYN11A在食品和饲料工业中具有巨大的应用潜力。Xylanase is a high-profile glycoside hydrolase with applications in brewing, feed, pharmacy and bioenergy industries,but most of xylanases are in active below 30 ~C. In order to obtain low temperature active xylanase, a xylanase gene, XYNllA, was cloned from Penicillium sp. L1 and expressed in Pichia pastoris GS115. After purification and enzyme assay, optimal pH and temperature were determined to be 3.5 to 4.0 and 55 ~C. This enzyme was stable at acid and neutral condition （pH 1.0 to 7.0） or under the treatment of 40 ~C for 1 hour. This xylanase displayed strong resistance to all tested ions and chemicals. Noteworthily, XYN 11A maintained a higher activity of 6 700 U/mg than a lot of GH 11 xylanase, and demonstrated higher activity （24% to 58%） at lower temperature from 20 to 40 ~C. After beechwood xylan hydrolysis for 16 h, the hydrolysates consisted mainly of xylobiose, xylotriose and xylotetraose and barely of xylose, thus XYN11A could be used for the production of prebiotic xylooligosaccharide. Possessing the features of acidophilic, highly active at lower temperature and oligosaccharide production, XYN11A demonstrated great potential in food and feed industrials.

关 键 词：木聚糖酶 高比活力 木寡糖 

分 类 号：Q55[生物学—生物化学]