重组Bacillus stearothermophilusβ-CGTase在β-环糊精制备中的应用条件优化

Studies on Preparation of β-Cyclodextrin Production UsingBacillus stearothermophilusβ-Cyclodextrin Glycosyltransferase and Reaction Conditions Optimization

DOI：10.3969/j.issn.1673-1689.2018.09.001

中文关键词: β-环糊精葡萄糖基转移酶 β-环糊精 酶转化 条件优化 同步转化

英文关键词: cyclodextrin glycosyltransferase,β-cyclodextrin,enzyme synthesis,optimal conditions,flasks fermentation

基金项目:

摘要点击次数: 197

全文下载次数: 310

中文摘要:

以作者所在实验室前期构建的产嗜热脂肪芽孢杆菌β-环糊精葡萄糖基转移酶（β-CGTase）重组短小芽孢杆菌作为菌种，经过摇瓶发酵，得到酶活为49 U/mL的β-CGTase粗酶液。以马铃薯淀粉为底物用β-CGTase进行单酶法转化制备β-环糊精，并对转化条件进行优化。结果表明，最优反应条件为：反应时间18 h，初始pH 6.0，反应温度50 ℃，底物质量浓度15 g/dL，加酶量13 U/g底物。在最优条件下，总转化率最高为73.9%，其中β-环糊精比例为98.7%。在此基础上，建立了采用普鲁兰酶与β-CGTase复配同步转化淀粉制备β-环糊精的新工艺，并且优化了普鲁兰酶的加酶量。结果表明，当普鲁兰酶加量为50 U/g淀粉底物，反应时间18 h时，总转化率达到最高81.4%，其中β-环糊精占比97.7%。

英文摘要:

Previously，a recombinantBrevibacillussp. producing the Bacillus stearothermophilus cyclodextrin glycosyltransferase was constructed. In this study，the strain was cultured in shake flask for 48 h，it showed that the highest extracellular enzyme activity was 49 U/mL. The supernatant of the medium was used as crude enzyme for the production of β-cyclodextrin. Then the reaction conditions，such as initial pH，reaction temperature，starch concentration，CGTase dosage，pullulanase dosage and reaction time，on the yields of β-cyclodextrin was investigated. The optimized conditions for the conversion as the following：the initial pH was 6.0，the reaction temperature was 50 ℃，initial starch concentration was 150 g/L ，CGTase concentration was 13 U/mL，pullulanase concentration was 50 U/g starch. Under this conditions，the reaction was continued for 18 h，thecyclodextrin yield is 81.4% and the proportion of β-cyclodextrin is 97.7%.

查看全文 查看/发表评论 下载PDF阅读器