毕赤酵母表面展示泰国红木β - 葡萄糖苷酶催化合成烷基糖苷的探讨Study on the synthesis of alkyl glycosides from the surface of the Pichia pastoris on the surface of Thailand 摘要:（摘要内容经过系统自动伪原创处理以避免复制，下载原文正常，内容请直接查看目录。） 烷基糖苷是一类运用可再生原料分解的新型非离子外面活性剂，具有没有毒、对皮肤和眼睛无安慰、相容性好、一些抗菌素特征和完整生物降解等长处，所以在洗濯剂、食物、和日化用品等工业中应用远景非常辽阔。固然今朝工业上重要是化学分解法，但因为化学法同时会存在a和β异头物，并且运用重金属作为催化剂，泰语毕业论文，存在平安隐患。酶法与之比拟具有选择性强、常温常压的平和反响前提和分解进程简略等长处。基于酵母外面展现技巧获得的细胞外面展现DC-BGL的全细胞催化剂，不只制备办法简略、本钱较低，并且相当于固定化酶，简略处置便可以收受接管，并能再次运用。在水-醇双相系统顶用于分解烷基糖苷，战胜了游离酶在分别纯化、再生和轮回运用等方面的艰苦，使得酶法分解烷基糖苷远景加倍辽阔。本课题以外面展现DC-BGL的毕赤酵母GS115作为全细胞催化剂催化分解烷基糖苷，并研究了顺水解和转糖苷两种分歧反响类型，试图采取二步法分解中长链烷基糖苷。在顺水解反响系统中，重点考核了5mL反响系统中含水量、酶添加量、葡萄糖添加量等几个主要身分对分解BG的作用，以便后续的反响系统缩小。在5mL反响系统中，BG的最优反响前提为：8%的pH3.0乙酸-乙酸钠缓冲液，酶粉添加量0.2g，葡萄糖添加量0.1g，50℃，200r/min反响时光72h，转化率为48.93%。按最优的前提在反响釜中缩小到1L系统，50℃，200r/min反响72h后转化率为40.1%，略低于小瓶直达化率。在1L系统反复运用全细胞酶粉，第二批次的转化率快要下降了一半，仅为24.08%。为了进步酶分解烷基糖苷的效力，商量了份子构建进步酶表达量和反响系统中添加助溶剂的作用情形。最初搜集反响釜中的反响液扭转蒸发年夜部门正丁醇，析出BG固体的可以作为转糖苷的底物。在转糖苷反响中，仍以外面展现DC-BGL的毕赤酵母GS115为全细胞催化剂，BG作为糖基供体，转糖苷分解中长链烷基糖苷OG和DG。本研究重点剖析了反响系统中乙酸-乙酸钠缓冲液的pH值、水含量、酶添加量、底物BG添加量和温度等几个身分对转糖苷的作用。成果注解：在2mL反响系统中，当反响前提为15%的pH3.0乙酸-乙酸钠缓冲液，酶粉添加量0.05g，BG的添加量为10mg，50℃，200r/min反响时光3h，OG转化率到达最高为51.1%。全细胞酶粉在小瓶中反复运用5次，可反复操作性稳固，转化率没有下降。肯定BG转糖苷分解DG的前提为：在2mL反响系统中，当反响前提为15%的pH3.0乙酸-乙酸钠缓冲液，酶粉添加量0.03g，BG的浓度7.5mg/ml，50℃，200r/min反响3h，泰语专业论文，DG转化率到达最高为21.68%。按2mL的反响前提在2L反响釜中分解OG缩小到500mL系统，反响1.5h就到达最高转化率47.5%。在500mL系统中酶反复运用3次，转化率没有下降，与小瓶中反复酶运用试验成果分歧，丈量其残存水解酶活也没有丧失。最初肯定了BG转糖苷分解以上试验成果注解DC-BGL具有较好的转糖苷才能，转糖苷分解中长链烷基糖苷的转化率远远高于顺水解的，试验还证实细胞外面展现DC-BGL作为全细胞催化剂具有很好的操作稳固性。 Abstract: Alkyl polyglycoside is a kind of application of renewable raw materials decomposition new nonionic outside active agent and has no poison, no comfort to the skin and eyes, compatibility is good, some antibiotics features and complete biological degradation strengths, so in the washing agent, food and daily chemical products and so on industrial application prospect is vast. Although the industry is now an important chemical decomposition method, but because of the chemical method at the same time there will be a and beta, and the use of heavy metals as catalyst, there is a security risk. Compared with the enzyme method has the advantages of high selectivity, normal temperature and atmospheric pressure and the reaction conditions and the decomposition process is simple and so on. DC-BGL yeast outside show their skills obtained outside of the cells to show based the whole cell catalysts, not only of preparation method is simple, the cost is low, and quite in immobilized enzyme, simple disposal can accept, and can be used again. The use of the top of the water alcohol biphasic system for the decomposition of alkyl glycosides, defeated the free enzyme in the purification, regeneration and recycling applications and other aspects of the hard, making the enzyme decomposition of alkyl glycosides perspective is more extensive. This topic to the outside show DC-BGL Pichia pastoris GS115 as whole cell catalyst catalytic decomposition of alkyl glucoside, and a discussion of the Shun hydrolysis and transglycosylation two different types of chemical reactions, trying to adopt a two-step decomposition of long chain alkyl glucoside. In the CIS hydrolysis reaction system, the key factors of the 5mL reaction system, including water content, enzyme, glucose and other major factors on the impact of the decomposition of BG, so as to further reduce the reaction system. In 5 ml of reaction system, BG's optimal reaction conditions: 8% of pH 3.0 acetic acid sodium acetate buffer and enzyme powder added weight 0.2g. With the addition of glucose 0.1g, 50 DEG C, 200R / min reaction time 72h, transforming rate for 48.93%. According to the optimal condition in the reaction kettle is reduced to 1L system and 50 DEG C, h after the 200R / min of reaction conversion rate was 40.1%, slightly lower than the vial direct ratio. In the 1L system repeated application of whole cell enzyme powder, second batches of the conversion rate is about to drop by half, only 24.08%. In order to improve the effect of alkyl glycosides, it was discussed that the influence of Naka Kasuke's solvent on the expression of the enzyme and the reaction system was discussed. Initially collected in response to the reaction of the reactor liquid reverse evaporation of the majority of the Department of butanol, BG solid precipitation can be used as a substrate for the transfer of glycosides. In the reaction of the transfer, still in the outside to show DC-BGL Pichia yeast GS115 as the whole cell catalyst, BG as a sugar based donor, the long chain alkyl glycosides OG and DG. This research focuses on the analysis of the reaction system in acetic acid sodium acetate buffer of pH value, water content and enzyme adding amount, substrate BG add volume and temperature, several factors influence on the transglycosylation. Note: in 2ml reaction system. When the reaction conditions for 15% of pH 3.0 acetic acid sodium acetate buffer and enzyme powder added 0.05g, BG dosage was 10mg, 50 DEG C, 200R / min reaction time 3H og transformation rate reached the highest was 51.1%. The whole cell enzyme powder used repeatedly 5 times in the vial, repeated operation is stable, the conversion rate did not decline. Certainly the transglycosylation BG decomposition of DG premise is: in 2ml reaction system. When the reaction conditions for 15% of pH 3.0 acetic acid sodium acetate buffer and enzyme powder adding quantity was 0.03g, BG concentrations 7.5mg/ml, 50 DEG C, 3H 200R / min reaction DG transformation rate reached the highest 21.68%. According to the premise of the reaction of 2L in the 2mL reactor in the decomposition of OG reduced to 500mL system, the response of 1.5h reached the highest conversion rate of 47.5%. In 500ml system enzyme repeated application of 3 times, conversion rate has not declined, and vials repeated enzymatic test results are applied differences, measuring the residual hydrolytic activity nor lost. Initially affirmed the has better transglycosylation to transglycosylation BG above decomposition results annotation DC-BGL and transglycosylation decomposition of long chain alkyl glucoside conversion rate is much higher than the hydrolysis. The results also showed that outside of the cells show DC-BGL as whole cell catalyst has good operating stability. 目录: |
