عنوان مقاله [English]
In most of the oil fields, the produced oil contains some amounts of brine in form of water in oil emulsion. The general method to break the emulsion is chemical demulsifying process. Recently, biological methods have got more attention in emulsion separation applications. In this project, the Acinetobacter Calcoaceticus strain has been used to produce a demulsifying agent for emulsion breakage. The supernatant from centrifuging the fermentation media showed an appropriate ability in separation of the water-in-oil emulsion in two phases. To improve the produced demulisifier performance, the important conditions such as the culturing media pH, temperature and C/N ratio were optimized by using Box Behnken surface response methodology. The maximum emulsion breakage in the optimized conditions (i.e. pH=5, T=35 and C/N=10) was obtained equal to 95%. The results revealed that this strain has a high potential in production of effective surface active agents for breaking the oil emulsions.