Ammonium uptake by Gracilaria gracilis (Stackhouse) Steentoft, Irvine et Farnham (Gracilariales, Rhodophyta), from the Mar Piccolo of Taranto

In the present paper both the capacity and the rate of NH4+-N uptake from the native Gracilaria gracilis was assessed. Ammonium uptake was best described by a linear, rate-unsaturated in N-limitation (1.46±0.09 ?M N g-1dry h-1) and N-repletion (1.52±0.09 ?M N g-1dry h-1) nutrient status. The high uptake rate values observed showed that G. gracilis is suitable to remove NH4+-N in polyculture plants.