摘要
旨在表达来源于瘤胃厌氧真菌基因组的4个木聚糖酶基因A、C、D和F,并比较分析其酶学特性。首先根据大肠杆菌基因编码偏好,合成可在大肠杆菌中表达的木聚糖酶基因序列,然后采用同源重组的方法将各序列分别插入载体pET-28a中,在大肠杆菌BL21(DE3)宿主菌中异源表达,并研究其酶学特性,结果成功表达出来源于厌氧真菌的4个木聚糖酶基因。测定其酶学性质发现,4种木聚糖酶的反应最适pH值均为8.0;木聚糖酶D的反应最适温度为37℃,其余3种木聚糖酶的反应最适温度均为45℃;4种木聚糖酶具有广泛的温度稳定性和pH稳定性;金属离子Ca^(2+)、Mg^(2+)、Mn^(2+)显著促进木聚糖酶活性(P<0.05),而Zn^(2+)则有明显的抑制作用(P<0.05);4种木聚糖酶降解山毛榉木聚糖的能力显著高于其他底物(P<0.05)。本研究成功表达了4种来源于厌氧真菌的木聚糖酶,其良好的温度和pH稳定性具有潜在的工业应用价值。
In the present study,four xylanase genes,A,C,D and F,from the genome of ruminal anaerobic fungus,were successfully expressed on Escherichia coli BL21(DE3).The results showed that the optimal pH of the four xylanases was 8.0.The optimal temperature of D was 37℃and that of the others was 45℃.All of the four xylanases had a wide range of temperature and pH stability.Ca^(2+),Mg^(2+),and Mn^(2+)stimulated the activity of all the xylanases significantly(P<0.05),while Zn^(2+)inhibited the activity of these xylanases significantly(P<0.05).The degradation ability of the four xylanases to xylan from beechwood was significantly higher than that of other substrates(P<0.05).In conclusion,the present study expressed four xylanases from anaerobic fungus successfully,which had a wide range of temperature and pH stability and had a potential to be used in feed additives.
作者
马玉萍
薛天涵
成艳芬
朱伟云
MA Yuping;XUE Tianhan;CHENG Yanfen;ZHU Weiyun(Laboratory of Gastrointestinal Microbiology,Nanjing Agricultural University,Nanjing 210095,China)
出处
《畜牧与兽医》
北大核心
2021年第1期24-30,共7页
Animal Husbandry & Veterinary Medicine
基金
国家自然科学基金(31772627)
江苏省“一带一路”技术合作项目(BZ2018055)。
关键词
木聚糖酶
厌氧真菌
大肠杆菌
异源表达
xylanase
anaerobic fungus
Escherichia coli
heterologous expression
