NOVELTY - A novel polymeric material APR-3 is produced by culturing a microorganism in a thiamin containing medium and the produced APR-3 is stored in the medium. The polymeric material has oil and water separability, aggregation activity, specified sugar content, does not contain amino sugar, uronic acid and protein, and has predefined molecular weight, spectral characteristics and viscosity.    USE - For production of flocculant (claimed) for waste water treatment (claimed).    ADVANTAGE - The culture solution obtained by cultivating APR-3 producing microorganism in thiamin containing medium has high oil-water separability and kaolin aggregation activity. The culture is obtained with stability in high yield and mass production can be performed easily. The flocculant for waste water treatment in environment-friendly and is obtained inexpensively.    DETAILED DESCRIPTION - A culture obtained by culturing a microorganism having APR-3 polymer producing ability in a thiamin containing medium, the polymer having oil and water separability, has the following characteristics;(i) sugar content (by phenol-sulfuric acid method): 64+/-2 weight %; (ii) amino sugar: undetectable (by Elson-Morgan method); (iii) Uronic acid: undetectable (by carbazole-sulfuric acid method); (iv) protein: undetectable (by ninhydrine method); (v) elemental analysis: carbon 40+/-2%, hydrogen 6+/-1% and trace amounts of nitrogen phosphorus and sulfur; (vi) the composition (molar ratio) of sugar and organic acid: galactose 1, glucose 5.6+/-0.1, succinic acid 0.6+/-0.1, pyruvic acid 2.5+/-0.1; (vii) molecular weight: at least 2x106; (viii) viscosity (by viscometron rotational viscometer, SS-2 rotor, 25degreesC, rotation speed 3-60 rpm, solvent pure water, 0.5 weight % solution of H type APR-3): 9000+/-1000 cP; (ix) solubility: soluble in water, easily soluble in alkali, insoluble in methanol, ethanol and acetone; (x) specific rotation (20degreesC): -17 to -15degrees; (xi) IR spectrum absorption band (cm-1): 2700-3700, 1730, 1600, 1400, 1160. INDEPENDENT CLAIMS are also included for the following: (i) Preservation of microorganism having APR-3 producing ability. The APR-3 producing microorganism is preserved in a thiamin containing medium; (ii) A flocculant produced by microorganism; and (iii) Waste water processing method. Waste water containing suspended solids is contacted with a flocculant (produced by microorganism), to aggregate the solids and settle the suspended impurities.