Abstract: 300 strains marine Streptomyces were isolated and purified from the samples, obtained from Jiaozhou Bay, Qingdao. Marine Streptomyces sp. M259 is one of the 300 strains marine Streptomyces, a high yield blue pigment produce. This paper mainly describe the fermentation and extraction methods of the blue pigment, and the results of our experiments showed that the blue pigment has no antibacterial activities to the eight microorganisms and the absorption peak is at 590nm. Moreover, it can be well dissolved in water and the color of blue pigment solution is red in acidic condition and blue in alkalescent condition. The effectsof light, temperature, sugar, reducer, metallic ions, and food additives are inconspicuous on blue pigment stability. The poisonous experiments confirmed that the blue pigment is an actually innoxious substance and can be safely applied in industrial production.

Key words:  , marine Streptomyces； blue pigment； physical and chemical properties；