Abstract
This paper describes the formation of DBCC and other unidentified vitamin B_<12> analogues from cyanocobalamin during thermophilic anaerobic digestion of waste distillage of acetone-butanol fermentation factory. After 24 hours of addition of cyanocobalamin, mixture of bacterial cells and sludges was centrifuged and extracted with hot ethanol. The alcoholic extract was concentrated in vacuo, purified by phenol treatment and passed through DEAE-cellulose column. Elution was carried out successively with water (orange-red colored fraction, tentatively named DC-l), 0.1 N acetate buffer (pH 4.7) (orange-red colored, DC-2), and 0.1 M NaCl・acetone mixture (brown colored, DC-3). DC-1 showed vitamin B_<12> activity on E.coli No. 215 and coenzyme activity in Abeles・Lee's intramolecular oxidation-reduction system. From the absorption spectrum and its changes by light and cyanide, and the behaviors in paperionophoresis, the identity of DC-1 with DBCC was concluded. The yield of DBCC was about 20% of added cyanocobalamin. DC-2 and DC-3 exhibited the growth effect on E.coli, though lower than that of DBCC, but no coenzyme activity in Abeles・Lees system. From the results of chromatography, spectroscopy and paperionophoresis, it was considered that DC-2 consisted of two unidentified cobamides and DC-3 contained unidentified analogues or decomposition products of cyanocobalamin.
