Organic pollutants and microbial communities :insight from coastal lagoon sediments of the Po river delta

The purpose of this work was to explore the level of contamination by organic pollutants (Polycyclic Aromatic Hydrocarbons, Nonylphenols, Bisphenol A) and the response of the functional properties of the microbial communities in coastal lagoon sediment. Overall the analysed sediments (12 sites in four lagoons) showed a moderate pollution (mean ?PAHs 65.0±23.0; ?NP 52±30, BPA 19.0±9.3; ng/g). The ratio between the bacterial C production (BCP) and respiration rates (CR) of the benthic microbial community varied linearly with ?PAHs and ?NP concentration (r=0.43, p<0.05). The highest contamination levels showed as well relatively high extracellular enzyme activities (beta-glucosidase, lipase and aminopeptidase activities). Such trend let infer a higher rate of growth of the microbial biomass in the contaminated sediment that can uphold the development of communities adapted to exploit specific food sources.