Investigation on the inactivation of Prorocentrum lima and degradation of diarrhetic shellfish toxins via peroxymonosulfate-based advanced oxidation process

Prorocentrum lima, a frequent harmful algal bloom species, secretes diarrhetic shellfish toxins (DSTs) that cause severe human gastrointestinal disorders. This study investigated a peroxymonosulfate (PMS)-based advanced oxidation process utilizing sulfate radicals for simultaneous algal inactivation and toxin degradation, addressing the current research gap in marine algal control. Microscopic analyses (optical/SEM) revealed structural disintegration and cytoplasmic leakage in treated cells. The observed 45.55-69.24 % reduction in chlorophyll a concentration critically impaired photosynthetic activity and DSTs biosynthesis. A 94.68 % decrease in viable cell ratio after 5 h PMS exposure confirmed effective algal eradication. Complementary mouse bioassays and LC-MS quantification demonstrated progressive toxin detoxification, evidenced by extended survival times and reduced DSTs concentrations. Membrane integrity analysis showed characteristic oxidative stress responses: malondialdehyde (MDA) levels surged during initial exposure (0-15 min), followed by superoxide dismutase (SOD) activity elevation (15-30 min) as cellular defense activation. The combined cell mortality and toxin attenuation confirm the dual efficacy of this approach. This cost-effective, operationally simple method presents a viable strategy for mitigating P. lima blooms and associated toxin hazards in marine environments.