利用固定化耐高温木聚糖酶生产木二糖

Production of Xylobiose by Using Thermostable Thermotoga maritima Xylanase B (XynB) Immobilized on Nikel-chelated Eupergit C

将重组海栖热袍菌(Thermotoga maritima)极耐热木聚糖酶B固定于镍螯合环氧载体Eupergit C 250L(固定化XynB)上,水解玉米芯汽爆液连续生产低聚木糖,特别是木二糖。固定化XynB操作稳定性很高,批次水解15次仍保持92%的初始水解活性。90℃下连续水解168h后保持83.6%的初始水解活性,连续操作半衰期为577.6h(24d)。HPLC分析表明,连续水解液中主要含有49.8%木二糖和22.6%木糖。活性碳层析柱可吸附木二糖,利用乙醇梯度洗脱木二糖的收率为84.7%,纯度为97.2%。因此,固定化XynB可用于水解玉米芯汽爆液高效生产木二糖。

The thermostable recombinant xylanase B （XynB） from Thermotoga maritima MSB8 was immobilized on nikelchelated Eupergit C 250L, and then used to hydrolyze the autohydrolysis explosion liquor of corncob （AELC） for continuous production of xylooligosaccharides, especially xylobiose. The immobilized XynB had a good operation stability and still retained its relative activity of 92% after 15 cycles of hydrolysis at 90 ℃. The immobilized XynB retained 83.6% of its initial hydrolysis activity even after 168 hours of hydrolysis reaction and demonstrated a half-life time of 577.6 hours （24 days） for continuous hydrolysis. HPLC analysis showed that xylobiose （49.8%） and xylose （22.6%） are the main products during continuous hydrolysis. Xylobiose was absorbed on an activated charcoal column and eluted with a linear gradient of ethanol to obtain xylobiose with 84.7% yield, and 97.2% purity. Therefore, the immobilized XynB can be applied for the efficient production of xylobiose from AELC.