The producing strain TP-A0595 was isolated from a leaf of leek Allium tuberosum collected in Toyama, Japan. Strain TP-A0595 was cultured at 30 ℃ for 4 days on a rotary shaker (200rpm) in four 500 ml/K flasks each containing 100 ml of the seed medium consisting of soluble starch 1%, glucose 0.5%, NZ-case (Humco Scheffield Chemical Co.) 0.3%, yeast extract (Difco Laboratories) 0.2%, tryptone (Difco Laboratories) 0.5%, K₂HPO₄ 0.1%, MgSO₄.7H₂O 0.05% and CaCO₃ 0.3% (pH 7.0). Three-ml of the seed culture were transferred into one hundred 500 ml/K flasks each containing 100 ml of the production medium consisting of glucose 0.5%, glycerol 2%, soluble starch 2%, Pharmamedia (Difco Laboratories) 1.5%, yeast extract 0.3% and Diaion HP-20 (Mitsubishi Chemical Co.) 1%. The pH of the medium was adjusted to 7.0 before sterilization. The inoculated flasks were shaken on a rotary shaker (200rpm) at 30 ℃ for 6 days.