乙酰微小杆菌生物合成5-甲基尿苷的研究  

A Study on the Biosynthesis of 5-Methyluridine

作　　者：上官俊龙[1] 苏境坦[1] 郑桂兰[1] 张文权[1] 张贵友[1] 谢莉萍[1] 王洪钟[1] 

机构地区：[1]清华大学生命科学学院,北京100084

出　　处：《广东海洋大学学报》2011年第4期30-36,共7页Journal of Guangdong Ocean University

基　　金：国家自然科学基金(40876068;21176138);国家基础科学人才培养基金(J1030622)

摘　　要：用乙酰微小杆菌(Exiguobacterium acetylicum)完整细胞作为酶源,催化鸟苷和胸腺嘧啶合成抗艾滋病药物关键中间体5-甲基尿苷,并对影响菌体生长和5-甲基尿苷转化率的因素进行了考察。采用紫外诱变方法获得高表达核苷磷酸化酶菌种,使5-甲基尿苷的转化率提高到了75.8%;对培养基进行了碳源和氮源的优化,结果表明,3 g/L葡萄糖、20 g/L玉米浆、4 g/L NH4Cl有利于菌体生长;通过响应曲面(Response Surface Methodology,RSM)法获得了较为合适的转化条件:0.03 g/L MnSO4加入到pH值为8.0的磷酸缓冲液,两种底物浓度均为67 mmol/L,反应温度为56℃。The complete cells of Exiguobacterium acetylicum were used as the enzyme sources to catalyze guanosines and thymines for synthesizing 5-methyluridine,which is the critical intermediate of AIDS drugs.Factors affecting bacterium growth and the conversion rate of 5-methyluridine were also studied.Through UV mutagenesis of Exiguobacterium acetylicum,a strain was acquired with high expression of nucleoside phosphorylase,which improves the conversion rate of 5-methyluridine to 75.8% and also optimizes carbon and nitrogen source for the culture medium.The results show that 0.3% glucose,2% corn plasma and 0.4% NH4Cl are better for bacterium growth.The best conversion conditions from Response Surface Method： with 0.003% MnSO4 added to phosphoric acid buffer with pH 8.0.The concentration of two substrates is 67 mmol/L,and the temperature is 56℃.

关 键 词：乙酰微小杆菌 5-甲基尿苷 紫外诱变 培养基优化 生物合成 响应曲面法 

分 类 号：Q939.9[生物学—微生物学] TQ920[轻工技术与工程—发酵工程]