Bacterial community structure and activity in fish farm sediments of the Ligurian sea (Western Mediterranean)

摘要: The environmental impact of a well-established fish farm has beeninvestigated in surface sediments the Ligurian Sea order to assess thebiodeposition, bacterial community structure and dynamics at mature stage oforganic enrichment.The Biopolymeric carbon (BPC) fraction organic matter phytopigmentconcentrations displayed very high values beneath cages. In particularlipid, carbohydrate chlorophyll-a concentrations werehigher sediment while protein did not show significantchange between control.Benthic bacteria were closely related enrichment their densitywas three times higher (up 3 × 1010 cellsg−1) stations cages being positivelycorrelated with BPC (n = 10, p < 0.05) lipid 0.05)concentrations. Colony forming units (CFU) counts heterotrophic bacteriaindicate shift relative importance gram negative bacterialfraction, displaying predominance theCytophaga/Flexibacter-like (CBF), as well theoccurrence pathogenic (such Vibrio) insediments farm. contrast, Gram positive moreprevalent control site where they represented up 90% total isolates.Aminopeptidase activity cages,whereas enzymatic per cell was lower. These data suggesta functional stress degradation rates represent potentialvaluable index imbalance supply removal organicmatter eutrophicated environments.Data presented this study also suggest that either biochemicalcomposition sedimentary selected microbialvariables may useful tools for evaluating effects organicenrichment due farming could be proposed new environmentalindices aquaculture on marine sediment.