利用基因组改组技术改良7-ACA产生菌

Improvement of 7-ACA Production by Genome Shuffling

将含假单胞菌(Pseudomonas)头孢菌素C(CPC)酰基转移酶基因ecs的pYG233质粒转入CPC产生菌顶头孢霉(Acremonium chrysogenum)中,构建可发酵7-氨基头孢烷酸(7-ACA)的基因工程菌(该菌株含有腐草霉素抗性标记phleo),为第一亲本。同时,构建含有潮霉素抗性标记(hgh)和ecs基因的重组质粒pYG236转化顶头孢霉菌株,以顶头孢霉(含有pYG236)作为第二亲本与第一亲本进行基因组改组,利用双重抗性标记作为融合子筛选条件,筛出一株7-ACA产量提高6.5倍的融合子工程菌。

pYG232, an expression plasmid containing CPC acylase gene ecs, was transformed into the CPC- producing strain Acremonium chrysogenum to construct a recombinant strain that could produce 7-ACA via fermentation. This plasmid contains phleomycin resistance gene （phleo）. The strain was used as one of the parental strains in genome shuffling, pYG236, which also contained ecs gene and hygromycin resistance gene （hgh）, was constructed and used as another parental strain in genome shuffling. The presence of both antibiotic resistance was used as the screening marker. By genome shuffling, a recombinant strain with 6.5 fold higher yield of 7-ACA over the parental strain was obtained.