β-葡萄糖苷酶合成龙胆二糖及产物分离  

Synthesis of gentiobiose by β-glucosidase and separation of the product

作　　者：张林[1] 王磊[1] 吴广兴[1] 勇强[1] 余世袁[1] 

机构地区：[1]南京林业大学化学工程学院,南京210037

出　　处：《林业工程学报》2017年第2期76-82,共7页Journal of Forestry Engineering

基　　金："十二五"国家科技支撑计划项目(2015BAD15B09)

摘　　要：以葡萄糖为原料,通过β-葡萄糖苷酶发生转糖苷反应制备龙胆二糖,研究不同来源的酶、反应温度、pH、加酶量、底物浓度、反应时间等对龙胆二糖的影响。结果表明:南京林业大学自产酶适合于龙胆二糖的制备,用900 g/L的葡萄糖溶液,加酶量为60 U/g葡萄糖,在pH 5、温度60℃的条件下,以80 r/min振荡转化24 h后得到浓度为46.9 g/L龙胆二糖。得到产物后采用高效阴离子交换色谱进行鉴定和定量。阳离子交换树脂2次洗脱分离后,得到纯度97.0%的龙胆二糖。用制备的龙胆低聚糖增殖青春双歧杆菌,36 h代谢了含有碳元素74.9mmol/L的碳源,生成含有碳元素62.1 mmol/L的有机酸和7.1 mmol/L的菌体,菌体浓度增长了3.8倍,表明实验得到的龙胆二糖可以有效增殖对人体有益的青春双歧杆菌。Gentiobiose was prepared by glucose catalyzed by β-glucosidase via transglycosylation. The effects of the source of theβ-glucosidase, reaction temperature, pH, β-ghicosidase dose, substrate concentration and reaction time on the gentiobiose were analyzed. The enzyme produced by Nanjing Forestry University was selected for the synthesis of gentiobiose. It was found that optimal conditions for synthesis were as follows： glucose at a concentration of 900 g/L was added withβ-glucosidase at a dosage of 60 U/g glucose; the mixture was incubated at pH 5, temperature of 60℃ with a shaking speed of 80 r/min; after 24 h, 46.9 g/L of gentiobiose was obtained. Anion exchange chromatography was used to quantitatively detected gentiobiose. Separation and purification of the gentiobiose product was completed by ion chromatography. Cation exchange resin was used in 2-step separation. The results showed that the gentiobiose was well separated from glucose after 2 thnes elution, getting a purity of 97.0%. The prepared gentiobiose was used for the proliferation of Bifidobacterium adolescentis. Sugar source containing 74. 9 mmol/L of carbon was metabolized for 36 h, generating organic acids of 62. 1 mmoL/L carbon and bacterium biomass of 7.1 mmoL/L carbon. The concentration of bacterium biomass increased by 3.8 times, indicating that the gentiobiose prepared in this study was an effective inducer for B. adolescent＆ which was beneficial to human health.

关 键 词：龙胆二糖 Β-葡萄糖苷酶 阳离子交换树脂 青春双歧杆菌 

分 类 号：Q533[生物学—生物化学]