Preparation Bacterial Culture Assay undiluted bacteria obtained from the laboratory of centre university of Gajah
Mada University. Before use, the bacteria were grown on media NA slant. Antibacterial activity test on films was carried out using the agar diffusion method. The zone of inhibition assay on solid media was used for determination of the
antibacterial effects of films against Escherichia coli . The edible films were cut into 6-mm diameter discs and then placed on nutrient agar plates, which had been previously seeded with 0.2 ml of inoculums containing approximately 105 - 106 CFU/ml of tested bacteria. The plates were then incubated at 37oC for 24 h. After that, the plates were examined for „zone of inhibition‟ on the film discs.