Abstract: The invention provides an acidic polysaccharide by culturing acidic polysaccharide-producing germ belonging to Aureobasidium sp. isolated from soil, which has no toxicity and is applicable to growth promotion by adding to feed, waste water-treating agent and foods.

Abstract: The invention provides an acidic polysaccharide by culturing acidic polysaccharide-producing germ belonging to Aureobasidium sp. isolated from soil, which has no toxicity and is applicable to growth promotion by adding to feed, waste water-treating agent and foods.

Abstract: A polysaccharide contains D-glucose as main constitutive sugar according to gas chromatography carried out through methylation in accordance with the Hakomori's method; and hydrolysis and to paper chromatography carried out through acid hydrolysis shows G.sup.1 .fwdarw.:.fwdarw..sup.3 G.sup.1 .fwdarw.:.fwdarw..sup.3 G.sub.6.sup.1 .fwdarw.=0.38-0.43:0.14-0.24:0.38-0.43 in gas chromatographic mass spectrometry (GC-MS method); has the signal of C.sub.1 at 103 ppm as measured from a .sup.13 C-nuclear magnetic resonance spectrum; shows characteristic absorption at 1720 cm.sup.-1 -1760 cm.sup.-1 and 890 cm.sup.-1 in an infrared absorption spectrum; has number average molecular weight between 50,000 and 500,000 as measured by the osmotic pressure; has a specific rotation [.alpha.].sub.D.sup.25 between +20 and +70; consists 42.0 to 45.0% of carbon, 5.7 to 6.7% of hydrogen, 0 to 1.0% of nitrogen, 0.2 to 0.8% of ash content and the rest of oxygen according to the results of an elementary analysis; contains 4.0 to 6.