title: Global hepatic gene expression in rainbow trout exposed to sewage effluents: a comparison of different sewage treatment technologies.
abstract: 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, ozonation (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.
authors.affiliation: Institute of Neuroscience and Physiology, Department of Physiology, The Sahlgrenska Academy at the University of Gothenburg, Box 434, SE-405 30 Göteborg, Sweden. filip.cuklev@neuro.gu.se
authors.forename: Filip
authors.initials: F
authors.lastname: Cuklev
authors.forename: Lina
authors.initials: L
authors.lastname: Gunnarsson
authors.forename: Marija
authors.initials: M
authors.lastname: Cvijovic
authors.forename: Erik
authors.initials: E
authors.lastname: Kristiansson
authors.forename: Carolin
authors.initials: C
authors.lastname: Rutgersson
authors.forename: Berndt
authors.initials: B
authors.lastname: Björlenius
authors.forename: D G Joakim
authors.initials: DG
authors.lastname: Larsson
mesh_terms: D000818:Animals; D002606:Charcoal / Q000378:metabolism; D004781:Environmental Exposure; D004784:Environmental Monitoring; D005786:Gene Expression Regulation; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006321:Heart / Q000187:drug effects / Q000254:growth & development*; D008099:Liver / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D017686:Oncorhynchus mykiss / Q000378:metabolism*; D009929:Organ Size; D010126:Ozone / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D012722:Sewage; D013548:Sweden; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D018840:HSP70 Heat-Shock Proteins; D012722:Sewage; D014874:Water Pollutants, Chemical; D002606:Charcoal; D010126:Ozone