Physiological response of freshwater microalga (Chlorella vulgaris) to triazine and phenylurea herbicides

Abstract

The effects of two herbicides used wide-spread, isoproturon (phenylurea) and terbutryn (triazine), on growth, dry weight, elemental composition, photosynthetic pigments and protein content, and cell volume assayed by flow cytometry in the freshwater microalgae Chlorella vulgaris were studied. Different parameters for algal activity show widely different sensitivities to these aquatic pollutants. After 96 h of herbicide exposure, terbutryn was the strongest inhibitor of growth, giving an EC50 value for growth twice lower than that for isoproturon cultures (EC50 terbutryn=0.097 microM; EC50 isoproturon=0.199 microM). However, lower concentrations of the triazine herbicide provoked an increase in the cellular density and growth rate of this microalga, not observed in the phenylurea-treated cultures. Cellular volume and dry weight of C. vulgaris cells were increased strongly in the presence of isoproturon and terbutryn. Other cellular parameters, such as pigment and protein content, were stimulated with both herbicides at higher concentrations.

Evolutionary consequences of multidriver environmental change in an aquatic primary producer

“…Similarly, in environments with seven drivers, populations have low growth rates but normal chlorophyll content and cell sizes. This is in line with other studies that demonstrated that in poor-quality environments populations invest in maintaining cell condition (38,39). In C. reinhardtii, cell size is related to population growth through its effect on cell division, as a critical size must be reached before cells divide (40)(41)(42).…”

Teor de clorofila e perfil de sais minerais de Chlorella vulgaris cultivada em solução hidropônica residual

“…Quando comparado com os resultados encontrados na literatura, observou-se que os valores de clorofila a e b foram superiores aos encontrados por RIOBOO et al (2002), que obtiveram respectivamente 0,14 e 0,05pg cel -1 em Chlorella vulgaris cultivada durante quatro dias em meio sintético similar ao do BBM.…”

Herbicide Contamination of Freshwater Ecosystems: Impact on Microbial Communities

“…For example, Ricart et al (2009) found that there was a reduction of the biovolume of diatoms at low concentrations of diuron. Herbicide exposure usually has a harmful effect, but some microalgae bioassays of various compounds have also revealed beneficial effects (Haglund, 1997;Franqueira et al, 1999;Wong, 2000;Rioboo et al, 2002;Yoshida et al, 2003). Stimulation of microalgal growth was, for example, found at the lowest paraquat concentrations tested in the study of Prado et al (2009).…”