抄録
Methanol-utilizing microorganisms were isolated from soil and air. One of the best vitamin B12 producers was identified as Klebsiella sp. No. 101. The bacterial growth and vitamin B12 production were stimulated by addition of organic nutrients, such as yeast extract and peptone, as well as vitamins, such as pyridoxine, nicotinic acid, p-aminobenzoic acid and biotin. Vitamin B12 production was observed only when methanol was used as the sole carbon source. The maximal vitamin B12 production was 130_??_140 μg per liter of the whole culture broth.