The benthic dinoflagellate Prorocentrum hoffmannianum M.A. Faust is typical of tropical warm waters and produces biotoxins responsible for diarrhetic shellfish poisoning (DSP). In this study, the effect of temperature and nutrient limitation on growth and toxin production of P. hoffmannianum isolated from field samples collected in the Florida Keys was investigated.

Batch culture experiments were ran at two temperatures (i.e. 21 ± 0.1 and 27 ± 0.1 °C) and under nitrogen-limited (14.7 μmol L⁻¹ N-NO₃- and 18.1 μmol L⁻¹ P-PO₄^3-) and phosphorus-limited (441 μmol L⁻¹ N-NO₃- and 0.6 μmol L⁻¹ P-PO₄^3-) levels with respect to control nutrient conditions (441 μmol L⁻¹ N-NO₃-and 18.1 μmol L⁻¹ P-PO₄^3-).

Both temperature and nutrient conditions significantly affected growth rates and maximum yield of P. hoffmannianum with the maximum values being recorded at the higher temperature and in the replete medium. Production of okadaic acid was induced under all conditions (from 13.5 to 859.8 pg cell⁻¹), with values up to one order of magnitude higher than those observed in other DSP toxin producing species.

Toxin production was enhanced under P limitation at 27 °C, corroborating the theory that toxin production is modulated by cell physiological conditions, which are in turn affected by a wide spectrum of factors, including environmental stressors such as nutrient availability. Toxin fraction released in the growth medium was negligible. No okadaic acid esters were detected in this strain of P. hoffmannianum.

底栖的鞭毛鞭毛原螯虾是热带温水的典型特征，会产生导致腹泻性贝类中毒（DSP）的生物毒素。在这项研究中，研究了温度和养分限制对从佛罗里达群岛收集的田间样品中分离的霍夫曼单胞菌的生长和毒素产生的影响。

分批培养实验在两个温度下（即21±0.1和27±0.1°C）和氮限制下（14.7μmolL ^-1 N-NO _3-和18.1μmolL ^-1 P-PO ₄ ^3-）进行，磷-有限的（441微摩尔大号^-1 N-NO ₃ -和0.6微摩尔大号^-1 P-PO ₄ ^3-）相对于对照的营养条件（441微摩尔L层^-1 N-NO ₃ -和18.1微摩尔大号^{- 1} P-PO ₄ ^3-）。

温度和营养条件均显着影响霍夫曼单胞菌的生长速率和最大产量，其中最大值在较高温度和充分培养基中记录。在所有条件下（从13.5到859.8 pg细胞^-1）都诱导了冈田酸的产生，其值比在其他产生DSP毒素的物种中观察到的值高一个数量级。

在27°C的P限制下，毒素的产生得以增强，这证实了毒素产生受细胞生理条件调节的理论，而细胞生理条件又受到多种因素的影响，包括环境压力，例如养分的可利用性。在生长培养基中释放的毒素分数可以忽略不计。在此霍夫曼单胞菌菌株中未检测到冈田酸酯。