EMULSAN ANALYSIS PRODUCED BY LOCALLY ISOLATED BACTERIAAND ACINETOBACTER CALCOACETICUS RAG-l

Growth of previously isolated bacteria from iranian oil reservoirs on different carbon and energysources and under varying conditions have been used to produce a class of extracellular microbialprotein-associated lipopolysaccharides named emulsan.several bacteria were previously isolated fromiranian oil reservoirs and designated as; i1am-l and paydar-4 . in present study, the isolated strains werecompared with standard sample of acinetobacter calcoaceticus rag-l from persian type culturecollection (ptcc 1641), irost. among the isolated strains, two strains were found to produce anextracellular, emulsifying agent when grown in mineral salt medium containing soya oil, ethanol orlocal crude oil. the isolated bacteria were cultured and further analysed using protein estimation,reducing sugar analysis, hemolytic activity, surface tension and emulsification activity tests. the crudeemulsifier of rag-i, paydar-4 and ilam-i were concentrated from the cell-free culture fluid byammonium sulfate precipitation to yield 1.89g, l.78g and 1.69g of bioemulsan respectively.emulsifying activity was observed over the entire production process. these investigations showed thatemulsan produced by isolated iranian crude oil reservoir were comparable with acinetobactercalcoaceticus rag-l which is made of carbohydrate backbone as its hydrophilic part (n-acetyl-dgalactoseamine,n-acetylgalactoseamine uronic acid, diamino-6-deoxy-d-glucose) and fatly acid chainas its hydrophobic portion .