A galactomannan and a branched (143)-P-D-glucan were isolated from the water hyacinth plant. The galactomannan, purified from the cold water extract, is composed of D-galactose and D-mannose in a ratio of 1.0:2.8. It has a (144)-linked D-mannose backbone, one out of three D-mannose residues being substituted with a single a-D-galactosyl unit. The branched (I-, 3)-P-D-gl~can isolated from the hot water extract has a main chain composed of P-(I-, 3)-linked D-glucopyranosyl residues, and two single P(146)-D-glucopyranosyl groups attached as side chains to, on average, every 5 sugar units of the main chain. In addition, the branching of the P-glucan occurs regularly at 0 -6 of the P-(143)-linked backbone.

An extracellular acidic polysaccharide, elaborated by Bacillus polymyxa, was composed of D-glucose, D-mannose, Dgalactose, and D-glucuronic acid (approximate molar ratio of 4:3: 1:l). Methylation and fragmentation analysis by partial acid hydrolysis indicated that the polysaccharide had a complicated, highly branched structure, consisting mainly of P(1+ 3) and (1 + 4) D-glycosidic linkages. The backbone chain containing D-glucose, D-mannose, and D-glucuronic acid residues is attached at the C-4, C-3, and C-4positions, respectively, one out of every three glucose residues being substituted at the C-2 position to form two kinds of branches at the C-2 and C-4 positions, with side chains of single or a few carbohydrate units that are terminated by D-glucose and (or) D-mannose residues.

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