安莎类抗生素是一类主要由放线菌产生的，结构独特、具有广泛生理活性的I型聚酮类大环内酰胺。其生物合成起始单元是3-氨基-5-羟基苯甲酸(3-amino-5-hydroxybenzoicacid，AHBA)。AHBA通过莽草酸途径的分支途径氨基莽草酸途径合成，其中催化最后一步反应的AHBA合酶基因有较高的保守性和特异性，很早就被用作探针筛选安莎霉素的生物合成基因簇。为了寻找新安莎类抗生素，本研究以AHBA合酶基因为筛选目标，通过多轮PCR并反复验证，从350株放线菌(主要是小单孢菌)中筛选到10株AHBA合酶基因阳性菌株，经过16SrDNA鉴定，全部为小单孢菌。 选取AHBA合酶基因分歧较大的N...Ansamycins is a family of macrolactam antibiotics with characteristic structure and potent physiological activity, which often was isolated from actinomycetes. The biosynthesis of all ansamycins began with a aminoshikimate pathway derived starter unit, 3-amino-5-hydroxybenzoic acid (AHBA). AHBA synthase, catalyzing the last step of AHBA formation, generally be chosen as anchor gene to clone the an...学位：理学硕士院系专业：生命科学学院生物学系_微生物学学号：2172008115253
