Production of cobamides by Butyribacterium rettgeri

Cobamide production by Butyribacterium rettgeri Barker and Haas (ATCC 10825) was studied on a laboratory scale. Yields of the order of 5 μg./ml. were obtained when this anaerobe was grown for 6 days at 37°C. in a medium containing glucose, cornsteep liquor, cobalt nitrate, calcium carbonate, and sufficient ammonium hydroxide to keep the pH between 6.0 and 7.2. All of the vitamin was found associated with the bacterial cells, and examination of extracts of these cells showed the presence of 5,6‐dimethylbenzimidazolylcobamide coenzyme in large quantities. Supplementation of the fermentation medium with a number of benzimidazoles resulted in formation of traces of “new” cobamides with these bases in the nucleotide protion of the cobamide. Supplementation with a number of purines did not result in incorporation of these moieties in the cobamide portion of the molecule.