ORIGINAL RESEARCH article
Front. Mar. Sci.
Sec. Aquatic Microbiology
Toxicity screening of eight Prorocentrum lima (Dinophyceae) strains of coastal China
Junkai Feng 1,2
Xueru Wei 1,3
Pengrui Ren 4
Peipei zhang 5
Minlu Liu 6
Gao Yue 7,8
1. Dalian Ocean University, Dalian, China
2. Dalian Ocean University College of Fisheries and Life Sciences, Dalian, China
3. Dalian Ocean University College of Marine Science and Technology and Environment, Dalian, China
4. Dalian University of Technology School of Environmental Science and Technology, Dalian, China
5. National Marine Environmental Monitoring Center, Dalian, China
6. Key Laboratory of Marine Ecological Conservation and Restoration，Ministry of Natural Resources /Fujian Provincial Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography Ministry of Natural Resources, Xiamen, China
7. Xiamen University, Xiamen, China
8. Xiamen University State Key Laboratory of Marine Environmental Science, Xiamen, China
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Abstract
Diarrhetic shellfish poisoning, caused by Okadaic acid (OA) and its analogues, threatens nearshore ecosystems and public health. This study systematically compared eight Prorocentrum lima strains isolated from China's coastal waters with respect to growth characteristics, toxin profiles and concentrations, toxin esterification status, and cytotoxicity. A multidimensional evaluation of toxin-producing potential and biological effects was conducted by integrating full-cycle culturing, LC–MS/MS analysis, and a Neuro-2a cell-based MTT bioassay. The results showed that OA and Diarrhetic shellfish toxin-1 (DTX-1) were detected in all strains, whereas DTX-2 was not detected. Total toxin levels measured after hydrolysis ranged from 17.07 to 31.84 pg OA-eq·cell⁻¹, and esterification ratios differed markedly among strains (53.37%–93.07%), with strain 1115 exhibiting the highest ratio. Growth kinetics varied among strains, and a resource-allocation trade-off was observed between growth rate and toxin production. Cytotoxicity assays showed that toxicity increased with both concentration and exposure duration; overall, free toxin extracts were significantly more toxic than total toxin extracts (p < 0.05), and toxic potency differed significantly among strains. OA-equivalent fitted concentrations back-calculated from the 24 h OA dose–response curve were generally higher than LC–MS/MS-measured concentrations, and fitted concentrations were significantly positively correlated with esterification ratios, suggesting that the contribution of esterified forms or their metabolites to overall toxicity may be underestimated by chemical analysis. In summary, P. lima exhibited pronounced intraspecific heterogeneity in toxin yield, chemotype, and biological effects. Integrating chemical analysis with cell-based bioassays enables a more comprehensive and accurate assessment of strain-associated ecological and public health risks.
Summary
Keywords
Diarrhetic shellfish poisoning, LC–MS/MS, Neuro-2a bioassay, Prorocentrum lima, toxicity screening
Received
16 January 2026
Accepted
10 February 2026
Copyright
© 2026 Feng, Wei, Ren, zhang, Liu and Yue. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Peipei zhang
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