Effect of deficient nutrients on growth and production of Prorocentrum lima

The data reported here focus on the response of a tropical strain of the dinoflagellate（ Prorocentrum lima），isolated from South China Sea（ Sanya），to nutrient stress induced by various levels of nitrogen（ N） and phosphorous（ P）. Cultures of P. lima were utilized to assess changes induced by N-limited levels（ 1/2N，1/4N， 1/8N，1/16N and 1/32N） and P-limited levels（ 1/2P，1/4P，1/8P，1/16P and 1/32P） with respect to control nutrient conditions. Low N and P availability resulted in low cell yield，total growth rate and total chl a，showing decreasing values with increasing nutrient limitation. The analysis of residual N，P nutrient concentrations showed that residual nitrogen and phosphorous were low under N-limitation（P< 1μmol/L，N-NO3 - < 1.3μmol/L，N-NH4 + <2.7μmol/L），but nitrate relatively high compared to N-limited condition under P-limitation ，which increased as P levels became more limited. P. lima preferentially took up ammonium under P-limitation when ammonium and nitrate coexist. N，P had a significant effect on the production of P. lima（ ANOVA，P <0.001）. Okadaic acid（ OA） concentration ranged from 13.02 to 42.16 pg/cell，it increased under all tested levels except 1/2-P. The highest OA cellular concentration measured（ 42.16 pg/cell） was obtained from 1/32P. These values were slightly higher than the highest OA concentration measured in N-limited conditions（ 1/32N，41.30 pg/cell）. Strong negative correlations were found between OA cellular content and division rate.