Abstract

Short-term bioassay of chlorophenol compounds such as di- and pentachlorophenol (DCP and PCP) on the movement parameters and photosynthesis activity is tested using Euglena gracilis. Cells were exposed to different concentrations of 2,4-dichlorophenol (2,4-DCP) and pentachlorophenol (PCP) for different incubation times. Results of acute toxicity tests of cell motility showed that Euglena was highly sensitive to PCP after direct exposure in comparison to 2,4-DCP (EC50 were 26.8 mgL−1 and 205.2 mgL−1), respectively. In contrast, 2,4-dichlorophenol shows significant impact on the movement and photosynthesis of the Euglena after longer incubation times (24 hours). Photosynthetic yield of Euglena was suppressed at concentrations 1.5 and 12 mgL−1 of pentachlorophenol and 2,4-dichlorophenol, respectively. This proves inactivation of photosystem II through inhibition of both electron transport and potential energy of photosynthetic membrane, whereas lower concentrations disturbed Photosystem II making it work ineffectively. Rapid, sensitive, and automatic measurements of several parameters are the main advantages of the studied bioassay.