利用梯度平板法结合紫外诱变、抗性筛选选育土霉素高产菌株

Breeding High-yielding Strains of Oxytetracycline with UV Mutagenesis，Oxytetracycline Resistance Screening and Gradient Plate Method

关键词:  龟裂链霉菌  紫外诱变  抗性筛选

Key words:  Streptomyces rimosus  UV mutagenesis  resistance screening

摘要:

以龟裂链霉素TMSⅠ12-66为出发菌株，通过紫外-氯化锂诱变处理，并结合梯度平板法、氯化锂和四环素复合抗性平板上筛选土霉素高产菌株。通过对致死率的考察，确定了紫外的最佳诱变剂量为90 s。在分离培养基上层加入氯化锂和底层加入四环素进行正突变株的定向筛选。经过选育得到一株土霉素的高产菌株TMSⅠ14-180，摇瓶发酵验证效价达22985 mg/mL，较出发菌株提高22.36%，经传代试验考察，该菌株遗传性状稳定。

Abstract:

UV mutagenesis，antibiotics resistance screening and gradient plate method were used to screen high-yielding strains of oxytetracycline directionly by using Streptomyces rimosus TMSⅠ12-66 as the original strain. The results showed that the dose of UV irradiation was determined 90 s in term of death rate. Using isolation medium with lithium chloride on the upper layer and tetracycline on the bottom layer, a high-yield oxytetracycline-producing strain named TMSⅠ12-66 was obtained, whose shaking production reached 22985 mg/mL, increased by 22.36 % than the original strain, its character was stable after five generations.