一株产CGTase环糊精葡萄糖基转移酶的细菌改性甜菊苷的研究  

Bioconversion of Stevioside by CGT7 Bacteria with Cyclodextrin Glucanotransferase Activity

作　　者：宋婷婷 尹慧慧 杨帆[2] 闫莽 陈育如 

机构地区：[1]南京师范大学生命科学学院江苏省微生物资源产业化工程技术研究中心江苏省功能微生物与基因组学重点实验室江苏省生物多样性与生物技术重点实验室,江苏南京210023 [2]格里菲斯大学环境学院和环境未来研究所

出　　处：《南京师大学报（自然科学版）》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)

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.

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 

分 类 号：Q814[生物学—生物工程]