PHOTOSYNTHESIS AND METABOLISM IN MARINE ALGAE: III. DISTRIBUTION OF PHOTOSYNTHETIC CARBON FROM C14O2 IN FUCUS VESICULOSUS

Abstract

F. vesiculosus plants were permitted to carry on photosynthesis in sea water in the presence of either Na₂C¹⁴O₃ or C¹⁴O₂, and the radioactive products of photosynthesis were examined by chromatography. The main compound in the ethanol-soluble fraction was mannitol, which contained up to 95% of the soluble activity. Citric acid and glutamine also accumulated considerable activity. Alginic acid was the main insoluble product of photosynthesis and appeared to be an active metabolite. Combined fucose also became radioactive, and was shown to be present in two forms. It was released from one by mild acid hydrolysis, but from the other only after much stronger hydrolysis. Neither the addition of nutrient salts to the sea water, nor increase in the amounts of CO₂ or carbonate supplied, caused much variation in the relative distribution of C¹⁴ among the photosynthetic products.