COMPARISON OF THE ADHESION PROPERTIES OF DELEYA-MARINA AND THE EXOPOLYSACCHARIDE-DEFECTIVE MUTANT STRAIN DMR

Deleya marina 219 (ATCC 25374) produces large quantities of an acidic exopolysaccharide and characteristically forms mucoid colonies and large aggregates of cells. The exopolysaccharide of wild-type D. marina cells appears to occur as both film and fibrils in electron micrographs. The organization of exopolymeric material was indicative of structural heterogeneity. A spontaneous rough-colony mutant defective in exopolysaccharide, D. marina DMR, has been isolated. The absence of exopolymer corresponds to a nonmucoid, nonaggregating, adhesion-altered phenotype. In microplate adhesion assays, wild-type cells grown at 19 or 25-degrees-C attached to hydrophilic surfaces but not to a hydrophobic surface. In contrast, mutant cells exhibited a significantly reduced level of attachment to hydrophilic surfaces and increased adhesion to a hydrophobic surface.