Comparison of the adhesion properties of Deleya marina and the exopolysaccharide-defective mutant strain DMR

Abstract

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°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.