Table of Contents
SRX Ecology
Volume 2010, Article ID 421950, 9 pages
Research Article

Short-Term Bioassay of Chlorophenol Compounds Using Euglena gracilis

Department für Biologie, Friedrich-Alexander-Universität, Staudtstraße 5, 91058 Erlangen, Germany

Received 4 August 2009; Revised 3 September 2009; Accepted 22 September 2009

Copyright © 2010 Hoda Ahmed and Donat-Peter Häder. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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.