Responses of the growth and biochemical composition of Prorocentrum donghaiense to different nitrogen and phosphorus concentrations

Abstract

Responses of growth, cellular total protein, carbohydrates and pigment composition in batch cultures of the marine dinoflagellate, Prorocentrum donghaiense, isolated from the Changjiang Estuary were studied in relation to concentrations of nitrate (0–256 μM) and phosphate (0–16 μM). The results showed that growth and biochemical composition of P. donghaiense were affected by changes in concentrations of N and P. Results showed luxury P consumption in all treatments. Algal division rates were strongly dependent on nitrogen and phosphorus concentrations. An increase in the initial N-added concentrations of the media led to an increase in the cellular total protein, ranging from 0.931 to 0.575 ng/cell during stationary phase. P concentration did not have an obvious effect on protein. Cellular carbohydrates significantly accumulated in both N-limited and P-limited conditions. There was a significant negative correlation between cellular carbohydrates and the specific growth rate. Nutrient availability influenced pigment synthesis. Cellular pigment contents in N-0 and P-0 treatments were significantly lower than that for high nutrient treatments during stationary phase. In addition, pigment ratios changes with different growth phases and nutrient status. Relationship between these biochemical parameters and initial nutrient concentrations showed the potential for specific ratios, including cellular protein/carbohydrate, cellular β-carotene/Chlorophyll a, cellular carbohydrate/cellular total P and protein/cellular total P, to be used as indicators of physiological status of P. donghaiense.