Emulsan analysis produced by locally isolated bacteria and acinetobacter calcoaceticus rag-1
Emulsifiers are widely used in industry, e.g., in medical and cosmetic products and in food systems. They can be used as agents to combat oil spills on beaches and in the sea. The materials that are currently in use commercially as emulsifiers are mainly produced by chemical synthesis. There is a great interest in studying bioemulsiflers because they have some advantages, such as theft selectivity for specific interfaces, generally low toxicity and biodegradability. The enormous diversity of microbial emulsifiers provides a rich source to fmd new agents which possess the right combination of properties for specific applications (Rosenberg and Ehora, 1998). Awide variety of petroleum degrading microorganisms has been found to bring about the formation of oil-in-water emulsions while growing on hydrocarbons (Pines, 2005). These emulsans are microbiological in origin and appear to be made either by the cells themselves or by the production of extracellular emulsifying agents (Gutnick et at., 1980). The gram negative bacterium Acinetobacter calcoaceticus RAG-i grows on a variety of different substrates as sole source of carbon and energy, including crude oil, middle chain length alkanes, alcohols, fatty acids and triglycerides (Fiechter, 1992). Its molecular weight is about 1 000KD in average (Pil, 1997).