Functional characterisation of a recombinant xylanase from Pichia pastoris and effect of the enzyme on nutrient digestibility in weaned pigs
Functional characterisation of a recombinant xylanase from Pichia pastoris and effect of the enzyme on nutrient digestibility in weaned pigs
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DOI：
10.1017/s0007114509993333
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发表时间：
2010-05-28
影响因子：
3.6
通讯作者：
Chen, Daiwen
中科院分区：
文献类型：
--
作者：
He, Jun;Yin, Jia;Chen, Daiwen
编码木聚糖酶2 （xyn2）的丝状中温真菌里氏木霉（Trichoderma reesei）的xyn2基因先前在毕赤酵母（Pichia pastoris）中表达。在本研究中，重组Xyn2是从15升发酵罐中制备的，并随后进行了表征。经证实，其分子量为21 kDa，最适pH为6.0，最适温度为60℃。用燕麦木聚糖进行测试，其k -m和催化速率常数（k(cai)）分别为1.1 mg/ml和512.4/s。通过对燕麦木聚糖降解产物的分析，证实该酶是一种以木糖三糖和木糖二糖为主要降解产物的内生木聚糖酶。将未加工的Xyn2添加到含木聚糖的饲粮中，以确定其对断奶仔猪生产性能和营养物质消化率的影响。结果表明，饲粮中添加浓度为500 U/kg的Xyn2可使仔猪平均增重提高16.9%。P < 0.05
The xyn2 gene of a filamentous mesophilic fungus, Trichoderma reesei, coding xylanase 2 (Xyn2) was previously expressed in Pichia pastoris. In the present study, the recombinant Xyn2 was prepared from a 15 litre fermenter, and subsequently characterised. It has been confirmed to have a molecular mass of 21 kDa, an optimal pH of 6.0 and an optimal temperature of 60 degrees C. When tested using oat-spelt xylan, it showed a K-m and catalytic rate constant (k(cai)) of 1.1 mg/ml and 512.4/s, respectively. Analysis of the products from oat-spelt xylan degradation confirmed that the enzyme was an endoxylanase with xylotriose and xylobiose as the main degradation products. The unprocessed Xyn2 was supplemented to a xylan-containing diet to determine its influences on performance and nutrient digestibilities by weaned pigs. Results showed that the average body-weight gain increased 16.9 % when piglets received Xyn2 at a concentration of 500 U/kg diet. There also was a positive (0.05 < P