PHOTOSYNTHESIS AND METABOLISM OF MARINE ALGAE: II. A SURVEY OF RATES AND PRODUCTS OF PHOTOSYNTHESIS IN C14O2

Abstract

The rates and products of photosynthesis of 14 species of brown, red, and green marine algae have been determined. C14O2was supplied in a special apparatus which gave a continuous record of uptake. This apparatus is described in detail. The products of photosynthesis were extracted, separated by paper chromatography, and their radioactivity was determined. The main product was invariably mannitol in the brown algae, floridoside or a glycerol-mannoside in the reds, and sucrose in the greens. Hydrolysis of the insoluble residues released radioactive amino acids, glucose, galactose, and other carbohydrates. Although the soluble products were characteristic of each group, the insoluble products were much the same in all three groups. The rates of CO2assimilation ranged from [Formula: see text] to 4 mg. of CO2per hour per gram of fresh plant. No correlation of the rate of CO2uptake was observed with either the morphology or the taxonomy of the algae.