Preparation, characterization and functional properties of a novel exopolysaccharide produced by the halophilic strain Halomonas saliphila LCB169T

A novel exopolysaccharide, designated hsEPS, was successfully prepared from the high-salt-fermented broth of a novel species Halomonas saliphila LCB169T by ethanol precipitation, anion-exchange and gel-filtration chromatography, and its structure was well-characterized by means of chemical and spectral analyses. Results showed that hsEPS was primarily composed of mannose and glucose with a relative weight-average molecular weight of 5.133 × 104 g/mol. It was deduced that the major backbone contained (1→2)-linked α-D-Manp and (1→6)-linked α-D-Manp with branches substituted at C-2 by T-α-D-Manp and at C-6 by the fragment of T-α-D-Manp-(1→2)-α-D-Manp-(1→. A sheet-like structure was observed under high magnification. The water solubility index, water holding capacity, oil holding capacity and foaming capacity of hsEPS were 98.0, 19.3, 1386.7 and 82.2%, respectively. It also exhibited outstanding emulsifying activity against all tested edible oils. Together, the resulted data indicated that hsEPS might serve as an active ingredient in food, cosmetics and detergents.