Some Aspects of Cobalt Metabolism by Rhodymenia palmata with Particular Reference to Vitamin B12 Content

The uptake of cobalt by Rhodymenia palmata from sea-water hasbeen studied by the use of radio-cobalt 6o. Periodic absorptionand desorption associated with illumination have been found.A dependence on carbon dioxide concentration has also been established.No effect of the addition of antibiotics to the sea-water canbe detected and no evidence of cobalt fixation as vitamin B₁₂has been obtained. Instead, another stable organic compoundof cobalt has been discovered, differing from vitamin B₁₂ inchromatographic and ionophoretic behaviour. The possible natureof the new compound is considered.