Global hepatic gene expression in rainbow trout exposed to sewage effluents: A comparison of different sewage treatment technologies
Journal article, 2012

Effluents from sewage treatment plants contain a mixture of micropollutants with the potential of harming aquatic organisms. Thus, addition of advanced treatment techniques to complement existing conventional methods has been proposed. Some of the advanced techniques could, however, potentially produce additional compounds affecting exposed organisms by unknown modes of action. In the present study the aim was to improve our understanding of how exposure to different sewage effluents affects fish. This was achieved by explorative microarray and quantitative PCR analyses of hepatic gene expression, as well as relative organ sizes of rainbow trout exposed to different sewage effluents (conventionally treated, granular activated carbon, zonation (5 or 15 mg/L), 5 mg/L ozone plus a moving bed biofilm reactor, or UV-light treatment in combination with hydrogen peroxide). Exposure to the conventionally treated effluent caused a significant increase in liver and heart somatic indexes, an effect removed by all other treatments. Genes connected to xenobiotic metabolism, including cytochrome p450 1A, were differentially expressed in the fish exposed to the conventionally treated effluents, though only effluent treatment with granular activated carbon or ozone at 15 mg/L completely removed this response. The mRNA expression of heat shock protein 70 kDa was induced in all three groups exposed to ozone-treated effluents, suggesting some form of added stress in these fish. The induction of estrogen-responsive genes in the fish exposed to the conventionally treated effluent was effectively reduced by all investigated advanced treatment technologies, although the moving bed biofilm reactor was least efficient. Taken together, granular activated carbon showed the highest potential of reducing responses in fish induced by exposure to sewage effluents.

Somatic indexes



estrogenic chemicals

Gene expression

Ozone treatment




stw effluent



aquatic toxicology

roach rutilus-rutilus

Sewage treatment technologies




Filip Cuklev

University of Gothenburg

Lina-Maria Gunnarsson

University of Gothenburg

Marija Cvijovic

University of Gothenburg

Chalmers, Mathematical Sciences, Mathematics

Erik Kristiansson

University of Gothenburg

Chalmers, Mathematical Sciences, Mathematical Statistics

Carolin Rutgersson

University of Gothenburg

B. Bjorlenius

D. G. Joakim Larsson

University of Gothenburg

Science of the Total Environment

0048-9697 (ISSN)

Vol. 427-428 106-114

Subject Categories

Other Medical and Health Sciences



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