Diarrhetic shellfish poisoning (DSP) is caused by the consumption of shellfish contaminated by diarrhetic shellfish toxins (DSTs) such as okadaic acid (OA) and dinophysistoxins (DTXs) produced by some species of dinoflagellates. To prevent the occurrence of human intoxication cases, inspection of DSTs (OA and DTXs) in shellfish is important. An instrumental method using liquid chromatography-tandem mass spectrometry (LC/MS/MS) has been recently employed in Japan for the monitoring of OA and DTXs in shellfish. For such analysis, reference materials (RMs) of OA and DTXs are essential. Demand for the reference materials, especially dinophysistoxin-1 (DTX1), is recently increasing in Japan. Production of the materials has been performed by mass cultivation of a dinoflagellate (Prorocentrum lima) strain that produces DTXs and OA, which indicates that the efficiency of production depends on the toxin production of the strain used. In this study, P. lima complex subclade 1e strain MIO12P was determined to be a high DTX1 producer among the three Japanese strains of the P. lima complex (subclades 1e, 1f, and 1i). It was clarified that the culture medium suitable for toxin production by strain MIO12P was metals mix SWII medium, and the optimal temperature and salinity for toxin production were 25 °C and salinity 30, respectively. The DTX1 yield (1265.3 ng ml⁻¹) of strain MIO12P cultured under the conditions described above was the highest reported worldwide. Prorocentrum lima complex subclade 1e strain MIO12P is expected to be useful for the sustainable production of DTX1 as a source of RMs for chemical and biochemical methods in the future.

腹泻性贝类中毒（DSP）是由食用腹泻性贝类毒素（DST）（如冈田酸（OA）和某些鞭毛藻类产生的狄诺氏物理毒素（DTX））污染的贝类引起的。为了防止发生人中毒事件，对贝类中的DST（OA和DTX）进行检查非常重要。日本最近已使用一种采用液相色谱-串联质谱法（LC / MS / MS）的仪器方法来监测贝类中的OA和DTX。对于此类分析，OA和DTX的参考材料（RM）是必不可少的。日本最近对参考物质，特别是dinophysistoxin-1（DTX1）的需求正在增加。材料的生产已通过对鞭毛藻的大规模培养来进行（Prorocentrum lima）产生DTX和OA的菌株，这表明生产效率取决于所用菌株的毒素生产。在这项研究中，利玛复杂亚枝1E应变MIO12P被确定为所述的三个日本菌株中高DTX1生产者利玛络合物（亚类型1E，1F，和1i）中。明确了适用于菌株MIO12P产生毒素的培养基是金属混合SWII培养基，产生毒素的最佳温度和盐度分别为25°C和盐度30。在上述条件下培养的菌株MIO12P的DTX1产量（1265.3 ng ml ^-1）是全世界报道的最高值。利马原中心 复杂的子小分子1e菌株MIO12P有望作为DTX1的可持续生产有用，作为将来化学和生化方法的RM来源。