| 5'-Nucleotide was wildly used in the Agriculture, Food industry and Medical industry, especially in the baby food as food additive. It can obviously improve the baby's immunity, maturation of intestines, the synthesis of lipoproteins and unsaturated fatty acids and reduce the occurrence of cold and diarrhea. It helps the baby's normal growth. 5'-nucleotide also can be used to synthesize the antivirus and anticancer medicaments as the acridine. The nucleotide's derivates had important uses in the illness of human's central nerve system and circulatory system. The purity of 5'-nucleotide has been considered as the focus of recent research. The small production of high-purified 5'-nucleotide in the country has restrained the development of national 5'-Nucleotide industry.In addition, 5'-Nucleotide is used in Food industry and fine chemical engineering. For example, the derivates of AMP are used as one of the components of cosmetic because of its innoxious and bland property. It can obviously improve the production of plants as the plant nutrition additive and improve the weight-added ratio and the utilization ratio. In the field of Biochemistry, new 5'-nucleotide, such as new oligonucleotide can be used as target cell's stylet to study gene's function and drawing genome library, especially to study the mechanism of anticancer medicaments and provide the new way to study Molecular Biology. Therefore, the shortage of raw material restrains the development of its ramification, as well as the development of pharmacy, fine chemical engineering and biochemical engineering.In this dissertation, 5'-nucleotide was produced by enzymic hydrolysis of RNA form the large scale production. Nuclease PI was produced from a new strain by inducement of original Pencillium citrimun. The enzyme was stable in the expression. We first used the new type Airlift Reactor in nuclease PI fermentation. Compared to the traditional Stirred Reactor, it shortened the fermentation period and increased the enzyme quantity, which the enzyme activity was lOOOu/ml, high than 700u/ml reported before, the fermentation time was 63h, shortened 27h. At the same time, we set up the growth kinetic model of Pencillium citrimun in the Airlift Reactor and provided the theory basic of controlling bacterium growth and enzyme production.The mixed solution of 5'-Nucleotide was carried out from the enzymic hydrolysis of RNA. In the process of hydrolysis, we absolved the problem of high concentration restrain of substrate by pre-disposing original enzyme. The reaction can be carried out in the relatively high concentration (5%) of substrate. The yield ofreaction reached more than 90%, which far exceeded the average level of 70%-85% in our country. The result showed that there was little impurity in the mixture of four Nucleotides. In addition, we first set up the enzymic hydrolysis model of nuclease PI to explain the phenomenon of high concentration restrain ability.Because of the complication of separation for four nucleotides, we separated the production step by step. That is, we separated the mixture of the four nucleotides preliminary, then purified the 5'-UMP , 5'-GMP, 5'-CMP, 5'-AMP respectively. A new cation resin was synthesized for the preliminary separation. The result showed that the absorption of nucleotides was good. High yield of nucleotides was got, which was 85% of UMP, 92% of GMP and CMP, 90% of AMP. Also, the purity of four nucleotides was 70% - 85 % of UMP, 90% of GMP and CMP, 90% of AMP. At the same time, The separate factor was used in describe the effect of separation. The separate factor was 1.11 of UMP and GMP, 1.87 of GMP and CMP, 1.84 of CMP and AMP which showed that the resin could separate this four kinds of nucleotides. In the further purification, we introduced the adsorb capability and separation factor to research the selectivity of resins.We ourselves synthesized four kinds of resins for the further purification. In the further purification, we introduced the adsorb capability and separation factor to research the sel...
|
PDF Full Text Request