استخراج و خالص سازي پيوسين S2 از سويه بومي سود و موناس آيروجينوزا 24A

Extraction and Purification of Pyocin S2 from an Endemic Pseudomonas Aeruginosa, Isolate 42 A

A collection of 82 wild type P. aeruginosa were obtained from different clinical sources (such as blood, stool, ear, burn and etc. . .). Pyocin typing of P. aeruginosa strains was performed as described by Fyfe and colleagues. Pyocin S2, a protease sensitive bacteriocin was produced by one of the endemic isolate which was named P.aeruginosa 42 A. Pyocin S2 production was induced by mitomycin C in an isolate which was able to produce the pyocin S2 in a small amount. The bacterial lysate was treated with 80% amonium sulfate solution and then proteins were precipitated by centrifugation. Pyocin S2 was purified by using ion exchange chromatography with CM-Sepharose CL-6B. Pyocin activity of the fractions was detected using the Govan spot testing method. The purity of active fraction was confirmed by using SDS- PAGE (10% aclylamide gel, staining with silver nitrate and coomassie stains). The results showed that one strain among the isolates produced pyocin S2. Mitomycin C (2 pg/m) induced the pyocin S2 production and increased its activity in this strain. In electrophoretic pattern (SDS - PAGE) a 74 KD single band was detected, indicating the purity of the pyocin S2 obtained and the precision of the extraction method.