Abstract
Recently, Weeks and Beck revealed that Flavobacterium aquatile strain Taylor responded specifically to thiamine in a simple medium and applied this organism for the assay of thiamine. In present work, growth response of the organism for thiamine was studied under varied conditions. As a result, it was confirmed that the growth of this organism was proportional to thiamine hydrochloride in the range of 0〜4.0mμg/ml when culture was carried out for 47 hours at 24℃ and pH 7.5 in the medium containing Trypticase 0.5%, glucose 0.5%, K_2HPO_4 0.05%, KH_2PO_4 0.05% and MgSO_4・7H_2O 0.02%. Under these conditions, microbiological activity of thiamine diphosphate was approximately equal to that of thiamine hydrochloride, and the activity of thiamine disulfide was somewhat inferior. On the other hand, O-benzoylthiamine, O-benzoylthiamine disulfide, and pyrimidine and thiazole moieties of thiamine were inactive. Practical application for the assay of thiamine in medicines and enriched foods was also investigated. The results were satisfactory and the values obtained were in good agreement with those assayed by thiochrome method.
