摘要
将教酒链霉菌L1105第10家族碱性木聚糖酶基因去除纤维素结合域(CBD)后将功能结构域基因xynAe SC克隆到毕赤酵母表达载体。经筛选得到重组工程菌GS1153-20,用甲醇诱导后产酶活力达到最高683±9U/m L。结果表明,重组木聚糖酶的最适p H为7.2,且在p H 6.2~8.6有较高的相对酶活;其最适温度为70℃,40~60℃时相对酶活力都在70%以上;重组酶Xyn Ae SC以燕麦木聚糖为底物时,酶活力最高,相对酶活力为桦木的259.7%±10.7%;对甘蔗渣木聚糖的酶活力最低,只有对桦木木聚糖酶活的16.0%±1.5%。研究表明,碱性木聚糖酶基因成功地在毕赤酵母中表达,且去除CBD域后,其酶学性质并未改变。
In this study,xylanase gene( xyn Ae SC) from Streptomyces chartreusis L1105 without carbohydrate binding domain( CBD) was cloned into expression vector. Recombinant strain( GS115- 3- 20) was fermented under the optimal condition for enzyme production. The yield of xylanase enzyme was up to 683 ± 9 U / m L. Results showed that recombinant xylanase had the high relative enzyme activity at p H 6. 2 ~ 8. 6,especially at 7. 2. It had the relative activity more than 70% at 40 ~ 60 ℃. The optimal temperature was around 70 ℃. It also showed the highest specific activity towards Oat-spelt xylan( equal to 259. 7% ± 10. 7% of relative activity towards Birch xylan). It also showed the lowest activity towards sugar cane pulp xylan( only equal to 16. 0% ± 1. 5% of relative activity towards Birch xylan). Its activity and properties had not significantly affected by removing CBD domain. All these study made this expression system attractive for industrial applications.
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2015年第3期33-38,共6页
Food and Fermentation Industries
基金
国家自然科学基金(31371723)
北京市自然科学基金(5144026)
食品科学创新团队(IDHT20130506)
