VITAMINS
Online ISSN : 2424-080X
Print ISSN : 0006-386X
Food chemistry and physiological function of pseudovitamin B12
Yuri Tanioka
Author information
JOURNAL OPEN ACCESS

2019 Volume 93 Issue 2 Pages 47-51

Details
Abstract

Vitamin B 12 (B 12 ) is synthesized only in certain bacteria. B 12 is concentrated mainly in the body of the higher predatory organisms in the natural food chain. Animal-derived foods such as meats, shellfish, egg, and milk are good dietary B 12 sources. In addition, a B 12 compound was contained abundantly in edible cyanobacteria. The B 12 compound present in edible cyanobacteria has been identified as pseudovitamin B 12 , an inactive corrinoid compound for humans. Therefore, this study was attempted to clarify the physiological function of pseudovitamin B 12 in cyanobacteria. The full-length of Spirulina B 12 -dependent methionine synthase was cloned into E.coli to clarify the physiological function of pseudovitamin B 12 in cyanobacteria. The recombinant Spirulina enzyme showed a higher affinity for methylpseudovitamin B 12 than methylcobalamin as a cofactor, indicating that cyanobacateria can utilize pseudovitamin B 12 as the cofactor for B 12 -dependent methionine synthase.
 It was further examined whether pseudovitamin B 12 exists in dietary sources other than edible cyanobacteria. As a result, a large amount of pseudovitamin B 12 was detected in turban shell and abalone, herbivorous sea snails. The content of B 12 in seaweeds which herbivorous sea snails consume as the food was very low, suggesting that pseudovitamin B 12 detected in herbivorous sea snails might be derived from cyanobacteria adhering to seaweeds.

Content from these authors
© 2019 THE VITAMIN SOCIETY OF JAPAN
Next article
feedback
Top