嗜热脂肪地芽孢杆菌木聚糖酶XynA的异源表达、酶学表征及低聚木糖的抗氧化性研究
Heterologous expression and characterization of xylanase XynA from Geobacillus stearothermophilus and antioxidant activity of Xylo-oligosaccharides
舒玉凤 1严鹤松 2魏凯峯 1薛颖 1胡悦 1李婵娟 1卢静静 1杜勇辉1
作者信息
- 1. 武汉设计工程学院食品与生物科技学院,湖北武汉 430205
- 2. 湖北轻工职业技术学院轻化工程学院,湖北武汉 430070
- 折叠
摘要
试验旨在开发木聚糖酶XynA,为饲用木聚糖酶提供新的资源.研究毕赤酵母中异源表达嗜热脂肪地芽孢杆菌XynA的最佳发酵条件、酶学性质及水解产物低聚木糖(xylo-oligosaccharide,XOS)的抗氧化性.结果显示,1.0％的甲醇诱导96 h,即可产生酶活约为33.7 U/mL的XynA粗酶液.XynA最适反应pH值为9.0,最适反应温度为65℃,在pH值5.0～10.5、45～75 ℃时能发挥80％以上活性.薄层层析(TLC)分析发现,XynA水解甘蔗渣木聚糖的主要产物为木三糖-木六糖,1 000mg/L的XOS对1,1-二苯基-2-三硝基苯肼(DPPH)自由基的清除率达到72.04％,对羟自由基的清除率达到99.16％.研究表明,异源表达后的XynA具有较好的酶活和稳定性,能够高效水解木聚糖产生XOS,有助于其在饲料工业中的应用.
Abstract
The experiment aims to develop xylanase XynA and provide a new resource for feeding xylanase.The XynA of Geobacillus stearothermophilus was heterologous expressed in Pichia pastoris,the optimal fermentation conditions,enzymatic properties and antioxidant properties of the hydrolysis product Xylo-oligosaccharide(XOS)were studied.The results showed that the crude XynA with enzyme activity of about 33.7 U/mL could be produced after 96 h induced by 1.0％methanol concentration.The optimum pH value of XynA is 9.0,the optimum temperature is 65 ℃,moreover,XynA remains above 80％of the activity at pH value ranging from 5.0 to 10.5 and temperatures between 45 and 75℃.Thin-layer chromatography(TLC)analysis revealed that the main products of the hydrolysis of bagasse xylan by XynA were xylotriose and xylohexaose.The scavenging rate of DPPH free radical reached 72.04％and the scavenging rate of hydroxylradical reached 99.16％with 1 000 mg/L XOS.The study indicates that XynA exhibits robust activity and stability,efficiently hydrolyzing xylan to produce XOS,thereby facilitating its application in the feed industry.
关键词
低聚木糖/木聚糖酶/异源表达/酶学性质/抗氧化Key words
XOS/XynA/heterologous expression/enzymatic properties/antioxidant引用本文复制引用
基金项目
湖北省自然科学基金项目(2022CFB567)
湖北省教育厅科学研究计划指导性项目(B2022424)
武汉设计工程学院校级科学研究项目(K202112)
湖北省大学生创新创业训练计划项目(S202314035002)
出版年
2024
国家科技期刊平台
NSTL
万方数据