Extraction and purification of pyocyanin

Abstract

Pyocyanin, the growth pigment produced by Pseudomonas aeruginosa, thought at one time to be a metabolic byproduct, was found to be important for the wellbeing of the organism and one of the important chemicals that allow it to survive in environments with competitive organisms. Different methods were used to extract and purify pyocyanin, some requiring major instruments. This study was performed to introduce an amended method for the optimal extraction and purification of pyocyanin. The results showed that the maximum yield was obtained from Cetrimide Agar plates seeded with the organism and held at room temperature for 96 hrs. The purified pyocyanin’s rate of degradation was dependent on the concentration of the sodium hydroxide added, its optimal storage solvents were deionized water and/or 80% methanol, but not dry chloroform in which the pigment quickly degraded. The purified pyocyanin was found to be thermolabile as it was stable for many days at lower temperatures but was immediately inactivated by higher temperatures. The suggested method is easy to implement, requires only regular laboratory facilities and gives a good yield of the pure pigment. Recommendations are also provided for proper storage to maintain its activity for a considerable period of time.