Aureobasidium -1,3-1,6 glucans and compositions containing such glucans, as well as methods of their preparation. Aureobasidium medium that contains -1,3-1,6 glucans, particularly medium produced by Aureobasidium strain FERM P-18099. The -glucans of the present invention have a variety of industrial and commercial uses, including applications in pharmaceutical or medical products or treatments, for the removal or control of environmental or microbiological contaminants, in cosmetics, and in nutritional products and foods.