一株虾青素产生菌的筛选诱变及初步鉴定

Screening,Preliminary Identification and Ultraviolet Mutagenesis of a High-yield Astaxanthin-producing Bacterium

从土壤中筛选获得一株虾青素高产菌株,命名为CTD004,采用紫外-可见分光光度计测得该菌株虾青素产量为28.8mg/L。通过对该菌株进行菌落形态观察,革兰氏染色和相关生理生化鉴定实验,以及利用16S rDNA序列的系统发育学分析,初步鉴定该菌株为假单胞菌属细菌,与GQ120653.1的亲缘关系较近。采用紫外诱变的方法提高该菌株产虾青素的能力,结果显示:菌液最佳的稀释倍数为10-6,最佳的诱变时间为15s,诱变后虾青素产量为64.6mg/L,比原菌虾青素产量增加了35.8mg/L,5次传代实验结果表现出较好的遗传稳定性。

A high-yield astaxanthin-producing bacterial strain,named CTD004,was isolated from the soil in our university in this study,which exhibited an astaxanthin yield of 28.8 mg/L according to the UV-vis spectrophotometric measurement.The strain was preliminary identified to belong to the genus of Pseudomonas and be closely related to the strain GQ120653.1 based on colonial morphology and Gram staining observations,physiological and biochemical tests and 16S rDNA sequence phylogenetic analysis.The genetic mutagenesis of the strain was induced by UV light radiation to obtain a new strain with higher ability to produce astaxanthin.The optimal dilution multiple of suspended cells was 10-6,and the optimal induction time was 15 s.The astaxanthin yield of the mutant strain obtained was 64.6 mg/L,35.8 mg/L higher than that of the starting strain.After 5-generation passage,the mutant strain still had excellent genetic stability.