| 摘要 |
PURPOSE:To obtain vitamin B12 in high concentration, by cultivating a methanol assimilating microorganism belonging to the genus Methanosarcina, capable of producing the titled substance in a medium comprising methanol as a carbon source an L-cysteine or thiosulfate as a sulfur source. CONSTITUTION:A methanol assimilating microorganism such as Methanosarcina barkeri DSM804, etc., belonging to the genus Methanosarcina, capable of producing vitamin B12, is cultivated in a medium comprising methanol as a carbon source, L-cysteine, a thiosulfate or a blend thereof as a sulfur source and no sulfide further. Production of vitamin B12 can be raised by further adding a cobalt salt to the medium containing a nitrogen source, an inorganic salt, vitamin, etc. The culture is anaerobically carried out and vitamin B12 is collected similarly to a conventional procedure. |
