Analysis of Vitamin B₁₂ in Food by Silica Gel 60 TLC and Bioautography with Vitamin B₁₂-Dependent Escherichia coli 215

Abstract

To evaluate whether certain foods contain vitamin B₁₂ or inactive corrinoids, a simple technique, bioautography with vitamin B₁₂-dependent Escherichia coli mutant after separation of the sample by silica gel 60 thin-layer chromatography, is available. By using the method, vitamin B₁₂-compounds found in some edible cyanobacteria are readily identified. This bioautography has great advantages (simplicity, speed, and inexpensiveness) for the analysis of vitamin B₁₂-compounds in food.

Keywords:

• Bioautography
• Edible cyanobacteria
• Escherichia coli 215
• TLC
• Vitamin B₁₂

ACKNOWLEDGMENT

Our research was, in part, supported by a fund for Comprehensive Research on Cardiovascular Diseases from The Ministry of Health, Labor and Welfare of Japan (to F.W.).