Abstract:

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.

Key words: astaxanthin, screening, identification, UV mutage