Effects of chlorpyrifos on the growth and ultrastructure of greenalgae, Ankistrodesmus gracilis

ASSELBORN, VM; FERNÁNDEZ, C.; DOMITROVIC, YZ DE; PARODI, E.R.

ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2015 vol. 120 p. 334 - 341

0147-6513

The effectof the organophosphorus insecticida chlorpyrifos on the growth, biovolume, andultrastructure of the green microalga Ankistrodesmus gracilis was evaluated. Concentrationsof 9.37, 18.75, 37.5, 75 and 150 mgL1 of chlorpyrifos were assayed along with acontrol culture. At the end of the bioassay the ultrastructure of algal cells fromcontrol culture and from cultures exposed to 37.5 and 150 mgL1 was observedunder transmission (TEM) and scanning electron microscopy (SEM). After 24 and 48h,treatments with 75 and 150 mgL1 inhibited the growth of A. gracilis; whereas after72 and 96 h, all the treatments except at 9.37 mgL1 significantly affected the algaegrowth. Thee ffective concentration 50 (EC50) after 96 h was 22.44 mgL1 ofchlorpyrifos. After the exposure to the insecticide, anincreasein the biovolumewas observed, with alarger increase in cells exposed to 75 and 150 mgL1.Radical changes were observed in the ultrastructure of cells exposed to chlorpyrifos.The insecticide affected the cell shape and the distribution of the crests in thewall. At 37.5 mgL1 electodense bodies were observed along with an increase in thesize and number of starch granules. At 150 mgL1 such bodies occupied almost thewhole cytoplasm together with lipids and remain sof thylakoids. Autospores formationoccurred normally at 37.5 mgL1 while at 150mgL1 karyokinesis occurred, but cell-separation-phasewas inhibited. The present study demonstrates that the exposure of phytoplanktonto the insecticide chlorpyrifos leads to effects observed at both cellular and populationlevel.