OIL-FIELD AND FRESH-WATER ISOLATES OF SHEWANELLA-PUTREFACIENS HAVE LIPOPOLYSACCHARIDE POLYACRYLAMIDE-GEL PROFILES CHARACTERISTIC OF MARINE-BACTERIA

The lipopolysaccharide structure of oil field and freshwater isolates of bacteria that reduce ferric iron, recently classified as strains of Shewanella putrefaciens, was analyzed using polyacrylamide gel electr ophoresis and a lipopolysaccharide-specific silver-staining procedure. The results demonstrate that all the oil field and freshwater isolate s examined exhibited the more hydrophobic R-type lipopolysaccharide, w hich has been found to be characteristic of Gram-negative marine bacte ria. This hydrophobic lipopolysaccharide would confer an advantage on bacteria involved in hydrocarbon degradation by assisting their associ ation with the surface of oil droplets.