Polysaccharide exopolymer adhesives from periphytic marine bacteria

—Periphytic micro-organisms frequently adhere to marine surfaces via the synthesis of polysaccharide exopolymer. For one such polysaccharide adhesive viscous exopolymer (PAVE), synthesized by Alteromonas colwelliana LST, production and purification were optimized and properties characterized. Maximum PAVE yields and best adhesiveness were obtained from cells harvested during the late logarithmic phase of growth in rich brain-heart infusion medium. The polymer was optimally purified by isopropanol extraction. It retained bond strength in sea water, possibly because of integral L-dihydroxyphenylalanine (Dopa) residues, the hydroxyl groups of which can successfully compete with H-bonds from sea water. Based on a limited survey of carbohydrate polysaccharide exopolymers from related marine bacteria, it is proposed that these compounds are promising natural product adhesives and marine surface coatings.