Research article

Effects of Cu²⁺, Ni²⁺, Pb²⁺, Zn²⁺ and pentachlorophenol on photosynthesis and motility in Chlamydomonas reinhardtii in short-term exposure experiments

Roman A Danilov and Nils GA Ekelund

Department of Natural and Environmental Sciences, Mid Sweden University, 871 88 Härnösand, Sweden

author email corresponding author email

BMC Ecology 2001, 1:1doi:10.1186/1472-6785-1-1

Published:	24 May 2001

Abstract

Background

Heavy metals, especially copper, nickel, lead and zinc, have adverse effects on terrestrial and in aquatic environments. However, their impact can vary depending on the nature of organisms. Taking into account the ability of heavy metals to accumulate in sediments, extended knowledge of their effects on aquatic biota is needed. In this context the use of model organisms (often unicellular), which allows for rapid assessment of pollutants in freshwater, can be of advantage. Pentachlorophenol has been extensively used for decades as a bleaching agent by pulp- and paper industry. Pentachlorophenol tends to accumulate in the nature. We aim to determine if photosynthesis and motility can be used as sensitive physiological parameters in toxicological studies of Chlamydomonas reinhardtii, a motile green unicellular alga. It is discussed if photosynthesis and motility can be used as sensitive physiological parameters in toxicological studies.

Results

The concentrations studied ranged from 0.1 to 2.0 mg l^-1 for copper, nickel, lead and zinc, and from 0.1 to 10.0 mg l^-1 for pentachlorophenol. Exposure time was set to 24 h. Copper and pentachlorophenol turned out to be especially toxic for photosynthetic efficiency (PE) in C. reinhardtii.

Conclusion

Copper and pentachlorophenol turned out to be especially toxic for PE in C. reinhardtii. Zinc has been concluded to be moderately toxic while nickel and lead had stimulatory effects on the PE. Because of high variance, motility was not considered a reliable physiological parameter when assessing toxicity of the substances using C. reinhardtii.