| 摘要 |
1451694 Vitamin B 12 RICHTER GEDEON VEGYESZETI GYAR RT 25 Oct 1974 [26 Oot 1973] 46215/74 Heading C2V In a method for increasing vitamin B 12 production by fermentation processes with mesophilic methane-producing bacteria under anaerobic conditions, during an enrichment period a nutrient concentrate containing mainly inorganic ammonium compounds as nitrogen source and mainly methanol as carbon source and having a N : C weight ratio of 1 : 10 to 1 : 20 is added in daily portions to a fermentation broth obtained from a vitamin B 12 fermentation process and containing living bacterium populations until the end of the enrichment period, and thereafter the fermentation is terminated and the obtained fermentation broth with an increased vitamin B 12 content is processed, or the fermentation is continued by periodically removing a portion of the fermentation broth and supplementing it with an equal volume of fresh nutrient medium containing mainly inorganic ammonium compounds as nitrogen source and mainly methanol as carbon source and having a N : C weight ratio of 1 : 10 to 1 : 20. Examples are given.
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