Partial structure of an extracellular mucopolysaccharide produced by a marine bacterium.

Abstract

The alanine associated with the extracellular mucopolysaccharide produced by a marine Pseudomonas (strain No. 9-12) was determined to be attached covalently to the carboxyl group of galacturonic acid and to have the D-absolute configuration. Depolymerization of this mucopolysaccharide was performed using techniques of mild acid hydrolysis, deamination, and periodate oxidation. Mild acid hydrolysis provided two polymers free of pyruvic acid with molecular weights of 5.5×104 and 8.5×104. Although the native polysaccharide was resistant to both deamination and periodate oxidation, partially N-deacetylated polysaccharide (M.W.=2.4×105) was sensitive to both reactions. Thus, some galactosamine residues were deaminated to 2, 5-anhydrotalitol and some galacturonic acid and galactosamine residues were oxidized by the peri-odate. Deamination and Smith hydrolysis yielded polysaccharides with molecular weights of 1.4×104 and 5.0×104, respectively.