STUDIES ON THE PREPARATION OF CRYSTTALLINE VITAMIN B_<12> FROM NATURAL RESOURCES : (XVI) ON THE EXTRACTION OF VITAMIN B_<12> FROM DRIED CELL FRACTION OBTAINED BY CENTRIFUGING THE SUPERNATANT LIQUOR OF NIGHT SOIL DIGESTER

Abstract

Several conditions were investigated for the extraction of vitamin B_<12> from the dried bacterial cell fraction obtained by centrifuging supernatant liquor of night soil treatment plant. Extraction of the vitamin was satisfactory by boiling for 30 minutes with 10 parts of 0.01〜0.1% KCN aqueous solution added to the raw material. Unless cyanide was present, vitamin B_<12> activity of extract proved low, especially with the Ochromonas assay.