费氏链霉菌中子辐射诱变菌株对新霉素的生物转化

Biotransformation of Neomycin by Mutational Strain of Streptomyces fradiae Mutagenized with Neutron Radiation

摘要:

对新霉素产生菌费氏链霉菌进行中子辐射诱变和突变株筛选, 获得不产新霉素的突变株。以突变株为转化菌种, 以新霉素为底物, 对转化发酵液进行高效液相色谱分析, 研究了不同转化条件对新霉素转化的影响。结果表明, 底物浓度、底物添加时间、底物添加方式、接种量、培养基装量、转化时间、碳源、氮源、pH、温度对新霉素转化具有不同程度的影响。以转化条件优化参数进行转化大量培养, 转化液经4步离子交换层析进行分离纯化, 薄层层析检测纯化样品为单一斑点。采用薄层生物自显影对获得的4个转化产物分离样品做生物活性检测, 发现4个样品对金黄色葡萄球菌和姜青枯假单孢杆菌都具有抑制活性, 1个样品对大白菜软腐病菌具有明显的抑制活性。

Abstract:

A mutant of neomycin-producer Streptomyces fradiae was obtained from cultures mutagenized with neutron radiation. Utilizing the mutational strain which can not produce neomycin in normal culture, the biotransformation of neomycin was studied at different conversion conditions. The analysis results of fermentation broth by high performance liquid chromatography showed that the culture conditions such as the concentration of substrate, adding time of substrate, adding method of substrate, inoculation amount, the volume of medium, transformation time, carbon sources, nitrogen sources, pH of media and temperature had different influence on neomycin transformation. The transformation products of neomycin were isolated from a large scale fermentation broth by ion exchange chromatography and identified by thin layer chromatography. The antibacterial activity of four purified samples against Staphylococcus aureus, Erwinia carotovora and Pseudomonas solanacarum were tested by bioautographic analysis. All four samples showed obvious inhibitory activity against Staphylococcus aureus and Pseudomonas solanacarum, but only one sample had inhibitory effect against Erwinia carotovora.