摘要
利用壳聚糖作为载体,将大肠杆菌BL21异源表达且纯化后的海藻糖合酶(TreS),采用吸附法制备成固定化酶。固定化单因素实验结果表明,最适海藻糖合酶与壳聚糖的加入量为32.0 mg/g,最适吸附时间为2.5 h。固定化酶最适反应温度为40℃,最适反应pH为6.0,酶活回收率为40.17%,重复使用9次后,固定化酶酶活残留率为64.64%,重复使用性良好。在4~60℃范围内放置20 min后,固定化酶的相对酶活均高于87%,与游离酶相比温度稳定性没有明显变化。在pH3.5~8.5范围内放置20 min后,固定化酶的相对酶活均高于60%,酸碱稳定性优于游离酶。反应进程试验结果表明,2 h时海藻糖得率达最大,为61.4%。
In this research,trehalose synthase（ TreS） was expressed using Escherichia coli BL21.Then,the purified enzyme was immobilized by chitosan according to adsorption method.After single-factor experiments,the optimal amount of the immobilized enzyme was 32.0 mg per gram of chitosan,the optimum time of binding was 2.5 hours.The optimum reaction temperature and p H of the immobilized enzyme were 40 ℃ and 6.0,respectively. The highest activity recovery of the immobilized enzyme was40.17%.The rate of residual enzyme activity of the immobilized enzyme was 64.64% after consecutive 9 cycles,which had reusability a good. The thermal stability of the immobilized enzyme was not significantly different compared with the free enzyme,and the relative activity maintained 87% after preincubation of the immobilized enzyme at different temperatures（ 4-60 ℃） for 20 min.However,the pH stability of the immobilized enzyme was superior,and the relative activity still retained 60%after preincubation of the immobilized enzyme in various pH values（ 3.5 - 8.5） for 20 min. The results of reaction processes indicated that the maximum trehalose yield of this immobilized enzyme was 61.4% at the point of 2 hours.
作者
黄珍
王慧
黄芳
李欣
王志
代俊
陈雄
HUANG Zhen, WANG Hui, HUANG Fang, LI Xin, WANG Zhi, DAI Jun, CHEN Xiong(Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Key Laboratory Fermentation Engineering （ Ministry of Education） , College of Bioengineering, Hubei University of Technology, Wuhan 430068, China)
出处
《食品工业科技》
CAS
CSCD
北大核心
2018年第19期130-133,141,共5页
Science and Technology of Food Industry
基金
国家自然科学基金(31300003)
关键词
海藻糖合酶
壳聚糖
固定化
海藻糖
trehalose synthase
trehalose
immobilization
chitosan
