IRON ASSIMILATION BY MARINE DIATOMS

Abstract
With the use of radioactive Fe it was found that the marine diatom Asterionella japonica utilized only particulate and/or colloidal Fe as a growth nutrient, whereas ionically complexed ferric ion, as the citrate, ascorbate, or artificial humate, was not available for uptake. A minimal content of Fe per cell needed for further division was established as 10-8 [mu] m/l. The ratio of minimal Fe to minimal phosphate agrees substantially with that found in natural samples.