Purification and characterization of a corrinoid-compound in an edible cyanobacterium Aphanizomenon flos-aquae as a nutritional supplementary food

The vitamin B(12) concentration of the dried cells of Aphanizomenon flos-aquae was determined by both microbiological method with Lactobacillus delbrueckeii ATCC7830 and chemiluminescence method with intrinsic factor. The Aphanizomenon cells contained 616.3 +/- 30.3 mu g (n = 4) of vitamin B(12) per 100 g of the dried cells by the microbiological method. The values determined with the chemiluminescence method, however, were only about 5.3% of the values determined by the microbiological method. A corrinoid-compound was purified from the dried cells and characterized. The purified corrinoid-compound was identified as pseudovitamin B(12) (an inactive corrinoid-compound for humans) by silica gel 60 TLC, C18 reversed-phase HPLC, ultraviolet-visible spectroscopy, and (1)H NMR spectroscopy. The results suggest that the Aphanizomenon cells are not suitable for use as a vitamin B(12) source, especially in vegans.