| 摘要 |
PURPOSE:To readily collect, purify and continuously produce vitamin B12, by attaching bacterium belonging to the genus Methanosarcina to a porous support and anaerobically culturing the bacterium. CONSTITUTION:Methanol as a carbon source, NH4Cl etc., as a nitrogen source, K2HPO4, MgSO4, NaCl, CaCl2, etc., as a inorganic salt, vitamins, Co salt etc. as slight amount of element and L-cystein, titanium citrate, etc., as a reducing agent are mixed to provide a fermentation medium having anaerobical atmosphere. Then, a vitamin B12-producing bacterium (e.g. methanosarcina barkeri DSM804) belonging to the genus methanosarcina and having methanol assimilation is attached to a porous support (e.g. silica porous support) having >=0.01m<2>/g surface area and anaerobically cultured in above-mentioned medium at 25-40 deg.C and 5.8-7.0pH, while controlling feed rate of the medium so as to keep <=2% (V/U) methanol concentration in the culture medium and vitamin B12 is then continuously collected. |
