Abstract :
Abstract The current study aimed to extract and purify colicin extracted from Escherichia coli (E,coli). One isolate was selected from 10 bacterial isolates obtained from Hilla Teaching Hospital in Hilla Governorate / Babylon, and all diagnostic and biochemical tests were carried out to ensure the purity of the bacterial isolates and to investigate their production of bacteriocin. Bacteriocin was extracted by centrifuging the bacterial suspension with a cooling centrifuge and concentrated by ammonium sulfate at a saturation rate of 70% and then by dialysis and ultrafiltration to get clear of the largest possible percentage of salts and impurities present in the solution. The protein extract was purified by SDS-PAGE polyacrylamide technique and its purity was confirmed by the appearance of a single band when electrophoresis was performed on polyacrylamide gel in the presence of SDS denaturants. The results of protein characterization showed that the molecular weight by electrophoresis on polyacrylamide gel was estimated to be 66 kDa. It was shown by matching the molecular weight of the protein with the molecular weights of standard proteins that the protein is colicin.
Keyword :
Keywords: Escherichia coli, colicin, ammonium sulfate, dialysis, ultrafiltration, SDS Page polyacrylamide