【作者】 肖林平；

【导师】 应汉杰；

【作者基本信息】 南京工业大学 ， 生物工程， 2003， 硕士

【摘要】 5’-核苷酸包括5’-尿嘧啶核苷—磷酸（5’-UMP）、5’-胞嘧啶核苷—磷酸（5’-CMP）、5’-鸟嘌呤核苷—磷酸（5’-GMP）、5’-腺嘌呤核苷—磷酸（5’-AMP）。在食品、医药和精细化工行业上有着广泛的用途，尤其是在婴儿食品（如奶粉）和医药领域的应用，有着不可替代的功能。 国内目前能进行四种核苷酸生产的厂家很少，且产品纯度不高，产量不大，每年都要进口大量的核苷酸，不能满足各行业对核苷酸的需求。原料不足的问题严重制约了核苷酸在我国食品、医药及精细化工等领域的应用和发展。 本文从大规模工业化生产四种核苷酸角度出发，利用成本低廉的酶解—离子交换分离的方法生产四种5’-核苷酸。 由于核苷酸的理化性质很相近，而且酶解液中各种杂质含量较多，导致下游分离纯化很困难。目前国内在分离方面存在的缺点是：所用树脂的分离度低；树脂利用率低；所得产品色素含量高；产品的收率和纯度较低等。 针对以上问题，本文提出了如下的分离策略：首先，由于酶解液中色素含量较多，使经树脂分离所得UMP和GMP中色素残留较多，最终导致成品质量的下降，所以我们用活性炭对酶解液进行脱色处理，使溶液中80％以上的色素被吸附除去，而核苷酸的吸附损失仅为2％左右。其次本文根据四种核苷酸的理化特性，首次自行合成了一种阳离子交换树脂，用于四种物质的初步分离，该树脂的优点是，对四种物质有较大的吸附容量；对四种物质间的分离度较高；洗脱所得四种物质的收率较高，平均收率大于93％；除UMP阳柱流出液纯度较低外，其余3种物质的纯度都大于95％，可直接经浓缩，结晶得到纯度大于98％的优质产品。针对阳柱UMP流出液中杂质含量高，难于分离除去的问题，本文利用自行合成的几种不同性质的阴离子树脂，通过静态筛选，得到一种对UMP的吸附容量、分离因数及杂质去除率都较高的阴离子树脂SD₃，其对UMP的吸附容量为0.133g／g．wet resin，分离因数α^UMP_后杂＞5.0，杂质去除率大于45％，吸附等温线的f（c）＜0，有利于吸附平衡。由SD₃吸附UMP的动力学特性得出UMP浓度在1g／L和6g／L时分别受液膜扩散控制和颗粒扩散控制。并对SD₃动态吸附、洗杂及洗脱UMP的过程进行了系统的研究，得出适合于SD₃分离纯化UMP的各种工艺 摘要条件，这些均未见报道。最后对于LTMP的结晶工艺条件进行了初步的探索。 用这种方法生产核着酸过程简单，对设备要求不高，生产成本低，适合于大规模工业化生产的要求。更多还原

【Abstract】 5’-Nucleotides include Uridine 5’-monophosphate(5’-UMP), Guanosine 5’-mono-phosphate(5’-GMP), Cytidine 5’-monophosphate(5’-CMP), Adenosine 5’-mono-phosphate(5’-AMP), They have wide use in the industry of food. medicine and fine chemicals, especially applying in the field of food and medicine, which are unrep laced.Presently companies inland that produce four kinds of 5’-nucleotides are very few, and the purity of products is not high, and yield is low. Every year we must import a lot of nucleotides, which can’t meet the demand. The shortage of stuff has restricted the use and development of nucleotides in food, medicine and fine chemicals.From the viewpoint of industrialization of nucleotides, this article studied the production method of four substances taking advantage of cheap zymohydrolysis-ion exchange separation.Because the physical and chemical property of nucleotides is very similar, and there are many impurities in the solution of zymolysis, the separation of down stream is greatly difficult. At present inland the shortcoming in separation is that the resolution and use ratio of resin is low, the amount of coloring matter contained in products is too high, and the purity and yield of nucleotides is too low and etc.Aiming at above problem, this paper put forward the strategy of separation as follows. Firstly, in view of great amount of coloring matter in solution, the quality of product is declined. So we decolor the solution by acticarbon, which makes 80% coloring matter be removed, but the loss of nucleotides is only about 2%. Secondly, on the basis of physical and chemical properties of four nucleotides, we first synthesized a kind of cation exchange resin by ourselves which is used to separate four matters preliminarily. The advantage of this resin as follows. The adsorption capacity of resin toward nucleotides is quite high. The resolution of resin toward four matters is high. The yield of products is high. too. The average yield greater than 93%. Except the purity of UMP is lower than three others, the purity of GMP, CMP, AMP is all greater than 93%, and they can be concentrated and crystallize high quality products whose purities are greater than 98%. The amount of impurity in the solution of UMP is great, which is removed difficultly. We synthesizedseveral differently qualitative anion resin, and screened out an anion resin-SD3 which possesses high adsorption capacity, high separation factor for UMP, and high wiping off ratio of impurity. The adsorption capacity of resin to UMP is 0.133g/g.wet resin, the separation factor a UMP后杂 is more than 5.0, the wiping off ratio of impurity more than 45%, and the adsorption isotherm line f (c)<0 is favorable for adsorption equilibrium. From the kinetic behavior of SD3 adsorbing UMP, we learned that when the concentrations of UMP are 1g/L and 6g/L, the diffusions come under FDC and PDC respectively. At the same time, we researched roundly the dynamic process of SD3 adsorbing, eluting UMP, from which we learned several technological conditions of SD3 purifying UMP. All of these haven’t been reported. Finally we preliminarily researched the crystallization technological conditions of UMP.This method possesses that procedure is simple, the demand for equipment is low, and the cost of production low, and is propitious to the demand of wholesale industrialization.更多还原