Some Aspects of Cobalt Metabolism byRhodymenia palmatawith Particular Reference to Vitamin B12Content

The uptake of cobalt by Rhodymenia palmata from sea-water has been studied by the use of radio-cobalt 6o. Periodic absorption and 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 can be detected and no evidence of cobalt fixation as vitamin B12 has been obtained. Instead, another stable organic compound of cobalt has been discovered, differing from vitamin B12 in chromatographic and ionophoretic behaviour. The possible nature of the new compound is considered.