Optimization Of Technology In The Preparation Of 5'-Nucleotide

There were four kinds 5'-nucleotides in common use, including 5'-adenine nucleotide(AMP), 5'-guanine nucleotide (GMP), 5'-cytosine nucleotide (CMP), 5'-uracil nucleotide(UMP), which played a very important role in people's life at present.In the study, the technology of producing nucleotides with enzymic method, whichmade use of waste yeast mud as raw material, was studied and improved. Firstly, themethod of the yeast broken wall was emphatically studied, compared with the wall-brokeneffect and nucleic acid-released effect. Of the wall-broken methods such as physicalmethod, chemical method, biological method. It was thought that the yeast broken wallmethod should be chose on the basis of the target product, not the high wall-broken rate.Ultrasonic wave and sodium chloide were united to break the yeast wall. In the process ofnucleic and extraction. The wall-broken conditions, were, as follows, the concentration ofyeast was 3%, the adding dosage of sodium chloride was 1.3%, the wall-broken powerwas 90W and the time was 35min, under these conditions, the extractive rate of nucleiccould amount to 90%.Secondly, the method how to remove the waste protein in the nucleic acid extractivesolution after yeast wall-broken, was preliminarily studied. The result indicated that it wasmuch better to remove the waste protein using the method that polyethylene glycolether(PEG) should be added after heating. The solution should be preserved 25min at90℃, then cooled and centrifuged, next, 10% polyethylene glycol ether with 20000molecular mass, was added to the upper dear liquid, then centrifuged. The take-off rateof waste protein could amount to 66.60%, and the loss rate of nucleic acid was 10.78%.The producing method of 5'phosphodiesterase with two different kinds of studied inthe paper. The enzyme was obtained through fermentation by Peniallium Citrinum. In thestudy, the separating and selecting process of the strain was studied, and the fermentativeconditions of the high-productive strain was also optimized, which made the enzymeactivity increasing from 89.71μ/mL to 277μ/mL,in addition, the technological conditionsof extracting 5'-phosphodiesterase from the malt was optimized. The enzyme activitymight amount to 245μ/mL. The hydrolyzation rate of the enzyme solution using the twomethods amountedto 55% and 50% respectively.Besides. the decolourization and purification of the nucleic acid hydrolyzationsolution were studied in the paper. The results suggested that the decolourization effect was much better at pH1.5, decolourizing 2h with 0.5% activated carbon. Ultrafittrationcould also be used to get rid of other substances, which was simple and effective. And itcould remove all the non-nucleotide substances. The removal rate of waste protein was48.75%, and the loss rate of nucleotide was only 4.46%.Finally, the separated conditions of the four kinds of 5'-nucleotide were alsodetermined in the study. The basic conditions of the positive ion resin to separate5'-nucleotide were obtained, which offered certain theoretical foundation for furtherpurifying necleotide.