Effects of nonyl phenol, a pesticide surfactant, on some metabolic processes of Chlamydomonas segnis

Abstract

Nonyl phenol (2.5 μg mL−1) was added to populations of synchronized cells of Chlamydomonas segnis Ettl. at four different phases of their life cycle, namely, at −4 and −2 h before the dark period (corresponding to the end of G1 and S phase), at the initiation of the dark period (the end of S phase and the beginning of G2), and 2 h into the dark cycle (at cytokinesis). The treatment was generally algistatic for all treatment periods. However, nucleic acid synthesis was substantially unaffected, leading to cells with a 1.6- to 2.0-fold augmentation of their DNA content. Algicidal effects were additionally obtained in cells treated in S phase. Perturbation of other metabolic processes including total protein and carbohydrate metabolism depended upon the timing of treatment relative to the phase of the life cycle.