抄録
1. The production of 5, 6-dimethylbenzimidazolylcobamide coenzyme from hydroxocobalamin or cyanocobalamin was studied using washed cell suspensions of Pr. shermanii. Under the experimental conditions almost complete conversion of hydroxocobalamin to the coenzyme was achieved at a concentration as high as 50μg/ml, which was about 10 times higher than that of the growing culture method reported previously.
2. As the concentration of the precursor increased, the degree of the transformation decreased and the formation of an unidentified vitamin B12 analogue was observed. The availability of cyanocobalamin as the precursor was only one-third of that of hydroxocobalamin in this procedure.
3. The utilization of the distillage of acetone-butanol fermentation broth was studied as a substitute for the yeast extract contained in the culture medium. The replacement of the half volume of the tap water with the distillage supported the bacterial growth nearly to the same degree as that in Bernhauer's medium.
4. The employment of a solid culture method shortened the incubation time of a liquid culture method by 5 days.
