METHOD FOR PRODUCING CURDLAN BY CULTIVATING A MICROORGANISM

摘要

PURPOSE: A method for producing curdlan by cultivating a microorganism is provided, thereby the curdlan can be cheaply and effectively produced in a higher yield. CONSTITUTION: The curdlan by cultivating a microorganism is produced by batch or fed-batch fermentation of Agrobacterium sp. in a growth medium containing carbon source, nitrogen source, phosphate and inorganic salt, wherein the hydrogen concentration of the medium is adjusted to 6.5 to 7.5 in order for the nitrogen source to be enough during a cell-growing phase; and the hydrogen concentration is adjusted to pH 5.0 to 5.5 during a curdlan producing phase after depletion of nitrogen sauce, in which the batch fermentation of Agrobacterium sp. is carried out under medium conditions of the initial concentration of carbon source of 100 to 160 g/l, the initial ammonium concentration as a nitrogen source of 0.5 to 2.5 g/l, the initial phosphate concentration is 0.5 to 4.5 g/l; and the fed-batch fermentation of Agrobacterium sp. is carried out under medium conditions of the initial concentration of carbon source of 80 to 140 g/l, and the initial phosphate concentration of 0.5 to 4.5 g/l, by adjusting pH of medium with ammonia water as a nitrogen source, and the supply of the nitrogen source is stopped and the concentration of carbon source is adjusted to 20 g/l or more when the curdlan production is initiated.