| abstract |
Growth of Acinetobacter Sp. ATCC31012 on various substrates and under varying conditions has been used to produce two classes of extracellular microbial protein-associated lipopolysaccnarides (the "emulsans") which, on a weight-for-weight basis, are probably the most efficient emulsifiers discovered and which possess certain characteristics that permit these unique extracellular microbial lipopolysaccharides to be widely used in cleaning oil-contaminated vessels, oil spill management, and enhanced oil recovery by chemical flooding. These classes have been named a-emulsans and β-emulsans, both of which have substantially the same polymer backbone but differ from each other in certain imoortant structural aspects. Deproteinization of emulsans by hot phenol extraction produces the lipopolysaccharide components (the "apoemulsans") of each of such emulsans. which components have been shown to be completely N-acylated and partially O-acylated heteropolysaccharides made up of a major amounts of D-galactosamine and an aminouronic acid, the O-lipoacyl portions of such apoemulsans containing varying percentages of fatty acid esters in which the fatty acids contain from about 10 to about 18 carbon atoms. Base hydrolysis under mild conditions of the emulsans and apoemulsans produces derivatives (the "ψ-emulsans" and "apo-ψ-emulsans", respectively) which are completely N-acylated and partially to completely O-deacylated. Base hydrolysis under strong conditions of any of these products produces another derivate (the "proemulsans") which is completely O-deacylated and is partially N-deacylated. Emulsans and apoemulsans, both of which biopolymers are strongly anionic, exhibit a high degree of specificity in the emulsification of hydrocarbon substrates which contain both aliphatic and cyclic components. In addition, these extracellular microbial polysaccharides as well as their O-deacylated and N-deacylated derivativesare adsorbed on and capable of flocculating aluminosilicate ion-exchangers, such as kaolin and bentonite. |