RESUMEN
DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one) is the main ingredient in SeaNine-211, a new antifouling agent that replaces organotin compounds to prevent the growth of fouling organisms on board. Biocides from antifoulants can cause problems for marine ecosystems by destroying non-target algal species. This study evaluated the potential adverse effects DCOIT using the Marine Chlorella sp. The concentration of DCOIT were set according to the semi-inhibitory concentrations for acute exposure experiments, and relevant oxidative stress indicators were measured to assess the acute toxic effects. The results showed that the inhibition concentrations (IC50) of DCOIT against Marine Chlorella sp was 2.522 mg/L. The genes related to photosynthesis and antioxidant capacity showed the effect of promoting low concentration and inhibiting high concentration. In addition, based on the ultrastructural observation and the expression analysis of photosynthesis related genes, it was found that DCOIT had a significant effect on plant photosynthesis.
Asunto(s)
Incrustaciones Biológicas , Chlorella , Contaminantes Químicos del Agua , Contaminantes Químicos del Agua/toxicidad , Incrustaciones Biológicas/prevención & control , Ecosistema , Tiazoles/toxicidadRESUMEN
Polystyrene (PS) is one of the most dangerous polymers, mainly because of the mutagenic or carcinogenic risk of the monomers used to produce it. Sea-Nine 211 is a commercial antifouling agent; its active ingredient is the biocide 4,5-dichloro-2-octyl-4-isothiazolinone-3-one (DCOIT). Micro- and nano-plastics have different synergistic effects on marine organisms together with organic pollutants. To understand the toxic effects of DCOIT and PS alone and in combination, marine Chlorella sp was selected as the experimental organism. The exposure concentration of DCOIT was set at 50 µg/L, and that of PS was set at 10 µg/L. The results show that all exposed groups promoted the growth of marine Chlorella sp in the late stage of exposure, and the recovery time of marine Chlorella sp in the exposed group containing PS was earlier. Changing trend of chlorophyll a was consistent with the growth trend. On the 15th day of exposure, the gene expression of the photosynthesis system in the combined exposed group showed a significant difference, and the cells produced oxidative stress. Scanning electron microscope observation shows the algae adhered to each other. The volume of algae cells in DCOIT and PS exposed groups decreased, and the internal structure of algae cells in each exposed group was damaged.