| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for purifying a microorganism-derived polysaccharide at a low cost by adding an acid to a microorganism culture solution to make it acidic, an alkali to the above solution to make it alkaline and then an acid to the above solution to keep it at a specific pH level, so as to separate the polysaccharide-containing liquid from the cell bodies. SOLUTION: This method efficiently separates and purifies a microorganism- derived polysaccharide by an economical and common procedure comprising a series of steps, (1) addition of an acid (e.g. acetic acid, hydrochloric acid, trichloroacetate or sulfuric acid) to a culture solution for a microorganism, such as methanol-assimilative bacterium (e.g. Methylophilus ATCC 31504 strain), to keep the solution at pH 3 or less, (2) addition of an alkali (sodium hydroxide, potassium hydroxide or ammonia) to the above solution to keep it at pH 12 or more, (3) addition of an acid to the above solution to keep it at pH 5 to 9, (4) separation of the polysaccharide-containing liquid from the cell bodies, and (5) addition of a water-soluble solvent and/or cationic surfactant to the separated polysaccharide-containing liquid. |
