Growth of Acinetobacter Sp. ATCC 31012 on various substrates and under varying conditions has been used to produce two classes of extracellular microbial protein-associated lipopolysaccharides (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. Base hydrolysis under mild conditions of the emulsans and apoemulsans produces derivatives (the ".psi.-emulsans" and "apo-.psi.-emulsans", respectively) which are completely N-acylated and partially to completely O-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 microbiol polysaccharides as well as their O-deacylated and N-deacylated derivatives are adsorbed on and capable of flocculating aluminosilicate ion-exchangers, such as kaolin and bentonite.