Nitrogen uptake and growth responses of seedlings of the brown seaweed Sargassum hemiphyllum under controlled culture conditions

摘要: For the purpose of indoor mass culture seedlings Sargassum hemiphyllum during spring and summer, a series experiments were designed to evaluate nitrogen (N) uptake, growth performance, N accumulation seedlings. Transient uptake rates by N-limited for nitrate (NO3 −), ammonium (NH4 +), urea more rapid than N-replete NO3 − revealed rate-saturating kinetic both Uptake NH4 + linear, whereas displayed Michaelis-Menten curves. The slope linear models or equivalently affinity calculated from curves was highest lowest urea, indicating that efficient at taking up +. Tissue content in seedling increased with increasing concentrations, values all three sources 150 μM. requirement support maximum varied 2.2-fold 0.39 ± 0.15% dry weight (DW) 0.84 ± 0.09% DW −, hence, became easily limited low availability. results showed cultured enrichment (50–100 μM) may be better able meet their high availability, although have higher capacities.