抄録
Nicotinic acid contents of Sacch. carlsbergensis during the growth were estimated. In the broth with tihamine, biosynthesis of nicotinic acid was greatly inhibited as compared with that in the broth without thiamine. In the broth with thiamine and pyridoxine, the biosynthesis was better than that in the broth with pyridoxine. All the nicotinic acid contents of the cells were increased in parallel with the growth except those in broth containing thiamine ; the inhibition of biosynthesis of nicotinic acid was interpreted as the vitamin B_6 deficiency caused by thiamine, resulting in the blocking the enzymatic system associated with vitamin B_6.
