The scope of this work is to study steps and optimal conditions for extraction and purification of Penicillin G from the culture broth of Penicillium chrysogenum A 88. The pH of the culture broth was adjusted to 3 and 1 gram of cetyl trimethyl ammonium bromide was added to 100 ml of culture broth to give 0.1% (W/V) before extracting. Extraction was performed at 4° C for 3 times with equal volume of amyl acetate for each time. Activated carbon was added to the extract to 0.5% (gram/100 ml) and stirred at 30° C for 30 minutes to remove impurity. The extract was then concentrated by rotary evaporating at 30° C under vacumm. Penicillin G was crystallized by adding sodium hydrogen carbonate solution to the extract to give the final pH of 7. This process yielded 52.6% of Penicillin G sodium salt with 96% purity.
