Authors: Yang Liu Nabil Majdi Michèle Tackx Alain Dauta Magali Gerino Frédéric Julien Evelyne BuffanDubau
Publish Date: 2014/10/12
Volume: 744, Issue: 1, Pages: 165-175
Abstract
Biofilms play a key role in selfdepuration processes in rivers Whilst meiofauna is known to be abundant within river phototrophic biofilms and to perform both grazing and bioturbation within these matrixes it is still unknown whether the activity of biofilmassociated meiofauna can influence the ability of biofilms to improve river water quality In this study we explored the effects of nutrient enrichment on river biofilm N–NO3 − uptake rates and associated meiofauna in microcosms for 5 days under nutrientenriched/nonenriched conditions Shorttime nutrient enrichment stimulated biofilmassociated bacterial and rotifer density as well as the biofilm uptake rates of N–NO3 − but not algal biomass Under nonenriched conditions N–NO3 − uptake rate tended to reach a plateau around 1042 μg g−1 AFDM h−1 At higher N–NO3 − concentrations realised under enrichment N–NO3 − uptake rate seemed to increase linearly reaching up to 4392 μg g−1 AFDM h−1 Our results showed a rapid response of rotifers to nitrate enrichment and suggest a possible link between bacteria–meiofauna interactions and the shortterm N uptake capacity of biofilmsMany thanks to Didier Lambrigot for his help with HPLC pigment analyses Yang Liu received a PhD grant by China Scholarship Council CSC Grant No 201208320230 We acknowledge a financial contribution of the “Observatoire MidiPyrénées” OMP Toulouse
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