The toxin-producing diversity of Prorocentrum lima (Dinophyceae) populations of coastal China

Prorocentrum lima (P. lima) is distributed in the four major seas of China. The diversity distribution of P. lima is confirmed by existing studies. The impact of this diversity feature on the difference of diarrhetic shellfish toxins (DSTs) components requires immediate investigation. Ten strains of P. lima were isolated from four major seas of China to explore the geographical differences in growth, toxicity production, and esterified composition. After 21 days of cultivation, strains isolated from the Bohai and Yellow China Sea (SHG and QD) exhibited slow growth and a maximum cell density of 3.3 × 10⁴ cells·mL^-1, whereas strains from the South China Sea (WZD and 3XS) demonstrated the highest growth rate and maximum algal density of 9.4 × 10⁴ cells·mL^-1. The total toxin content in single cells varied from 4.8 to 10.1 pg·cell^-1, with SHG and QD displaying the highest total toxin content at 10.1 pg·cell^-1. A total of 24 kinds of esterified components were identified across all ten strains of P. lima, comprising 43.9 %-92.2 % of total toxins, with the highest levels found in SHG and QD strains. Growth, toxicity production, and esterification of P. lima, taken from the four major sea areas of China, were significantly different. The contrasts in growth and toxicity potential revealed the existence of adaptive mechanisms of P. lima in different geographic environments, and the role of toxins in the adaptation mechanism requires further exploration.