Koichi Okutani

The flow properties of an extracellular mucopolysaccharide produced by a marine strain of Pseudomonas

The flow properties of the highly viscous mucopolysaccharide produced by a marine strain of Pseudomonas (No. 9-12) were investigated. The aqueous solutions of both the native and depyruvated forms of this mucopolysaccharide had yield values even at low concentrations. Flow indices for the native form increased with increasing concentrations, but remained constant for the depyruvated form at various concentrations. The structural viscosity of both the native and depyruvated forms increased with increasing concentration. The spinnability of the native form was determined to be much greater than that hyaluronic acid and potato starch. Electron micro-graphs of the gel of the native form showed microfibrils with network structures.

Partial structure of an extracellular mucopolysaccharide produced by a marine bacterium

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.