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

Lugar: Amsterdam; Año: 2015 p. 334 - 341

0147-6513

The effect ofthe organophosphorus insecticide chlorpyrifos on the growth, biovolume, andultrastructure of the green microalga Ankistrodesmusgracilis was evaluated. Concentrations of 9.37, 18.75, 37.5, 75 and 150 mgL-1 of chlorpyrifos were assayed along with a control culture. Atthe end of the bioassay the ultrastructure of algal cells from control cultureand from cultures exposed to 37.5 and 150 mg L-1 was observed under transmission(TEM) and scanning electron microscopy (SEM). After 24 and 48 h, treatmentswith 75 and 150 mg L-1 inhibited the growth of A. gracilis; whereas after 72 and 96 h, all the treatments exceptat 9.37 mg L-1 significantly affected the algae growth. The effectiveconcentration 50 (EC50) after 96 h was 22.44 mg L-1 ofchlorpyrifos. After the exposure to the insecticide, an increase in the biovolumewas observed, with a larger increase in cells exposed to 75 and 150 mg L-1.Radical changes were observed in the ultrastructure of cells exposed tochlorpyrifos. The insecticide affected the cell shape and the distribution ofthe crests in the wall. At 37.5 mg L-1 electodense bodies wereobserved along with an increase in the size and number of starch granules. At150 mg L-1 such bodies occupied almost the whole cytoplasm togetherwith lipids and remains of thylakoids. Autospores formation occurred normallyat 37.5 mg l-1 while at 150 mg L-1 karyokinesis occurred,but cell-separation-phase was inhibited. The present study demonstrates thatthe exposure of phytoplankton to the insecticide chlorpyrifos leads to effectsobserved at both cellular and population level.