Propionibacterium shermanii에 의한 비타민 B12의 생성에 영향을 미치는 배지첨가물들에 대한 연구

Study on the Effects of Supplemented Factors on the Production of Vitamin B12 by Propionibacterium shermanii

Following the study on the fermentation conditions influencing the production of vitaminB12 by Propionibacterium shermanii(Korean J Biotechnol. Bioeng. 7, 126-131, 1992), the effects of some factors supplemented in the medium on the production of vitamin B12 were studied. Maximum production of vitamin B12 was observed when Co+2 was supplemented at the concentration of 2-4ppm in the fermentation medium. Increase of the supplemented C0+2 to 12ppm did not inhibit the growth of the organism, but it accelerated the lysis of the organism. In the literature, peptone was reported to activate the biosynthesis of vitamin B12. Examination of the effect of peptone on the growth and the production of vitamin B12 showed that at early stage more vitamin B12 was observed in the supplemented medium, but no difference was observed in the later stage of fermentation. Examination of the time for addition and the amount of 5,6-dimethylbenzimidazole, a precursor known to influence the production of vitamin B12, showed that a maximum yield of vitamin B12 was observed when 15mg/L was added to the fermentation medium after 2 days'' incubation. The effect was comparable with the increase of the production of vitamin B12 when the fermentation condition was changed to aerobic condition after 2 days'' culture under anaerobic condition.