摘要
本文对筛选的一株产CGTase环糊精葡萄糖基转移酶的细菌(Bacillus sp.CGT7)转化并改性甜菊苷进行了研究,探讨了影响酶活性和转化效果的因素.实验结果表明,在CGT7菌的培养过程中,碳源、氮源、温度和初始pH等因素对菌株产酶活性均有不同程度的影响,适宜的碳源为马铃薯淀粉,氮源为豆粕粉,培养温度为30℃,初始pH值为8.5.适宜条件下培养的CGT7菌的酶活性可达544 U/mL,以甜菊糖苷为底物、环糊精为糖基供体时,转糖苷产物Stv-Glu浓度为0.61 mg/mL.
This work screened the strain CGT7 which produces cyclodextrin glucanotransferase, and studied its bioconver- sion and modification activities from stevioside into Stv-Glu. The efficient factors were discussed. Experimental results showed that carbon source,nitrogen source, temperature and pH value of culture medium can effect on cyclodextrin glu- canotransferase activity of CGT7 observably. Potato starch and soybean cake meal are the appropriate carbon and nitrogen sources with an initial pH value of 8.5 at 30 ℃. The cyclodextrin glucanotransferase activity of CGT7 culture medium reached 544 U/mL under the optimized condition, and the concentration of biocoversion product Stv-Glu was obtained at 0.61 mg/mL when stevioside was introduced as the substrate and cyclodextrin as the glycosyl donor.
出处
《南京师大学报（自然科学版）》
CAS
CSCD
北大核心
2017年第1期95-98,共4页
Journal of Nanjing Normal University(Natural Science Edition)
基金
江苏省高校自然科学研究重大项目(15KJA210002)
江苏省"六大人才高峰"高层次人才选拔培养项目(NY-011-2015)
关键词
环糊精葡萄糖基转移酶
甜菊糖
酶法改性
糖基供体
酶活性
cyclodextrin glucanotransferase, steviol glycoside, enzymatic modification, glycosyl donor, enzyme activity
