重组木聚糖酶的诱导表达及其定向制备低聚木糖的研究  

Induced Expression of Recombinantβ-1,4-Xylanase and Its Directional Preparation of Xylo-oligosaccharide

作　　者：解静聪 蒋剑春[1] 高月淑[1] 徐浩[1] 赵剑[1] 卫民[1] XIE Jingcong;JIANG Jianchun;GAO Yueshu;XU Hao;ZHAO Jian;WEI Min(Institute of Chemical Industry of Forest Products,CAF,National Engineering Lab.for Biomass Chemical Utilization,Key Lab.of Chemical Engineering of Forest Products,National Forestry and Grassland Administration,Key Lab.of Biomass Energy and Materials,Jiangsu Province,Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources,Nanjing 210042,China)

机构地区：[1]中国林业科学研究院林产化学工业研究所,生物质化学利用国家工程实验室,国家林业和草原局林产化学工程重点实验室,江苏省生物质能源与材料重点实验室,江苏省林业资源高效加工利用协同创新中心,江苏南京210042

出　　处：《林产化学与工业》2020年第5期99-106,共8页Chemistry and Industry of Forest Products

基　　金：国家重点研发计划资助项目(2017YFD0601001);江苏省自然科学基金青年项目(BK20160150)。

摘　　要：为降低酶法制备低聚木糖的成本并提高产品纯度,围绕重组木聚糖酶的诱导表达条件和酶水解木聚糖的工艺参数进行研究,考察了诱导剂浓度、诱导温度、诱导光密度(OD 600)值和诱导时间等因素对重组大肠杆菌(pTrc99A-podoxyn11-DE3)产重组木聚糖酶的影响,针对酶水解过程中酶用量、酶水解时间及产物分布情况进行了探讨。结果表明:在诱导剂浓度5 mmol/L,诱导温度32℃,诱导OD 600值1.2,诱导时间8 h的最佳诱导条件下,重组酶酶活力可达5.72 U/mL。玉米芯木聚糖质量浓度20 g/L,温度45℃,pH值5.5,重组木聚糖酶用量为60 U/g条件下水解12 h,酶解率可达49.90%,低聚木糖得率21.75%。杨木木聚糖质量浓度20 g/L,温度45℃,pH值5.5,重组木聚糖酶用量35 U/g条件下水解14 h,酶解率可达79.50%,低聚木糖得率73.30%。重组酶水解两种木聚糖的主要产物均为木二糖和木三糖,几乎不产生木糖。For reducing the cost of enzymatic preparation of xylo-oligosaccharides and improving the purity of the product,the conditions of induced expression of the recombinant xylanase and the parameters of enzymatic hydrolysis of xylan were studied.The effects of the inducer concentration,induction temperature,induction OD 600,and induction time on the recombinant xylanase production from recombinant Escherichia coli strain(pTrc99A-podoxyn11-DE3)were investigated.The enzyme dosage,enzyme hydrolysis time,and product distribution in the process of enzymatic hydrolysis were studied.The results showed that the optimal conditions were inducer concentration 5 mmol/L,the induction temperature 32℃,the induction time 8 h,and the induction OD 600 value 1.2.Under these conditions,the activity of recombinase could reach 5.72 U/mL.When the concentration of corn cob xylan was 20 g/L,temperature was 45℃,pH value was 5.5 and the amount of recombinant xylanase was 60 U/g,the hydrolysis rate was 49.90%and the yield of xylo-oligosaccharides was 21.75%after reacting for 12 hours.Under the condition of 20 g/L of poplar xylan,45℃,pH value 5.5 and 35 U/g of recombinant xylanase for 14 hours,the rate of enzymatic hydrolysis was 79.50%,and the yield of xylo-oligosaccharides was 73.30%.Xylose was not detected in the hydrolysis products of two kinds of xylans by recombinant xylanase and the products were main xylobiose and xylotriose.

关 键 词：重组木聚糖酶 诱导表达 低聚木糖 酶水解条件 

分 类 号：TQ35[化学工程]