Effects of nitrate and phosphate on growth and C2 toxin productivity of Alexandrium tamarense CI01 in culture.

Growth and C2 toxin productivity of a marine dinoflagellate, Alexandrium tamarense CI01 (ATCI01) which predominantly produces C2 toxin, were studied in unialgal batch cultures to optimize the concentrations of nitrate and phosphate for a maximal toxin yield. A range of start concentrations of the two major nutrients was determined in which algal growth was proportional to the nutrient concentrations used. The highest concentrations of nitrate and phosphate in this growth-enhancing range were 264 and 20 microM, respectively. In this concentration range, the C2 toxin yield (microg/l) and cellular toxin content (Qt, fmole per cell) reached a maximum at the lowest end of phosphate (5 microM) and the highest end of nitrate (264 microM). Further increase in the supply of nitrate continued to enhance the toxin yield. Our results indicated that the growth and toxin productivity of this algal strain in batch cultures had distinctly different optimal ranges of nitrate and phosphate concentrations. For a maximum toxin yield, a judicious use of phosphate under a nitrate-replete condition is called for.

[1]  Paul J. Harrison,et al.  Effects of nutrient limitation on toxin production and composition in the marine dinoflagellate Protogonyaulax tamarensis , 1987 .

[2]  Kevin J. Flynn,et al.  Growth dynamics and toxicity of Alexandrium fundyense (Dinophyceae): the effect of changing N:P supply ratios on internal toxin and nutrient levels , 2000 .

[3]  C. Hummert,et al.  Effect of different nitrogen/phosphorus nutrient ratios on the toxin content in Alexandrium minutum , 1999 .

[4]  M. D. Keller,et al.  MEDIA FOR THE CULTURE OF OCEANIC ULTRAPHYTOPLANKTON 1,2 , 1987 .

[5]  I. J. Hodgkiss,et al.  Are changes in N:P ratios in coastal waters the key to increased red tide blooms? , 1997, Hydrobiologia.

[6]  E. G. Vrieling,et al.  Harmful Marine Algal Blooms , 1995 .

[7]  B. Reguera,et al.  Nitrogen and phosphorus limitation in cultured Alexandrium minutum Halim does not promote toxin production , 1995 .

[8]  Donald M. Anderson,et al.  Dynamics and physiology of saxitoxin production by the dinoflagellatesAlexandrium spp. , 1990 .

[9]  G. Usup,et al.  Growth and toxin production of the toxic dinoflagellate Pyrodinium bahamense var. compressum in laboratory cultures. , 1994, Natural toxins.

[10]  D. Hsieh,et al.  Dynamics of C2 toxin and chlorophyll-a formation in the dinoflagellate Alexandrium tamarense during large scale cultivation. , 2001, Toxicon : official journal of the International Society on Toxinology.

[11]  S. Hall.  Toxins and toxicity of Protogonyaulax from the Northeast Pacific , 1982 .

[12]  Jean-Paul Parkhill.  Effects of salinity, light and inorganic nitrogen on growth and toxigenicity of the marine dinoflagellate Alexandrium tamarense from northeastern Canada , 1999 .