Pentachlorophenol induced physiological–biochemical changes in Chlorella pyrenoidosa culture

Present study investigated physiological and biochemical changes in a green alga culture (Chlorella pyrenoidosa) upon exposure to varied concentrations of pentachlorophenol (PCP) (0, 0.4 mg L−1, 2.5 mg L−1 and 10 mg L−1). The results revealed that with the increase of PCP concentration, a decrease of the algal biomass, levels of photosynthetic pigments (chlorophyll a, b and carotenoid), soluble protein and an increase of nitrate reductase (NR) activity were observed. This suggests that the PCP may serve as an uncoupler, causing low ATP level within the algal cells and led most of the NR molecules to be in the dephosphoration state (i.e. active from). Moreover, it shows that photosynthetic pigments especially carotenoid were more sensitive indicators to indicate PCP toxicity as compared to the other parameters.