Characterization of Purple Pigment Produced by Sponge Associated Actinomycete Strain Transformed by Ribosome Engineering

An actinomycete strain SCKA-96.5 was isolated from an unidentified sponge sample from Xisha sea.The strain produced grayish-white aerial mycelium on Guase’s No.I medium supplemented with seawater.The 16 S rRNA gene sequence of strain SCKA-96.5 showed that it was assigned to Streptomyces.Its mutant strain,SCKA-96.5K,obtained by ribosome engineering,was able to produce a purple diffusible pigment stably.The pigment was extracted;and its physicochemical properties were analyzed.The results showed that the maximum absorption wavelength was 600 nm;the pigment was stable to heat and food additives;its color changed significantly when pH changed;strong oxidant NaClO could destroy the pigment while weak reductants didn’t had any effect on the pigment.The purple pigment had the potential to be developed for future application as a kind of natural pigment.