Bioremediation of chronically oil-polluted marine sediment using beats of hydrocarbons-degrading bacteria

Bioremediation is a good kind of "green biotechnology" based on the microorganisms abilityto degrade hydrocarbons fractions.In this work sediment samples were collected from the industrial harbor of Priolo Gargallo(Augusta, Syracuse, Sicily - Italy), a chronically polluted area.Enrichment cultures and microbial isolation were performed. Amoung 258 bacteria and 5consortia isolated, strain S1 (Alcanivorax borkumensis, 98%) and two consortia (PSO andPSM) showed degradation rates of ~98% for linear and polycyclic aromatic hydrocarbons(PHAs) after 10 days of incubation (25±1°C, shaking 100 g). Taxonomic analysis (16S clonelibraries) of consortia showed as dominant genera hydrocarbonoclastic bacteria (HCB):Cycloclasticus sp. (~ 80%) in PSM and Alcanivorax sp. (~70%) in PSO.Bacteria and Consortia selected were tested to develop a bioremediation strategy usingchitosan/ agar beats for polluted marine sediments recovery.9 different bioremediation treatment were performed: Control (C), ImmobilizedHydrocarbonoclastic bacteria(HCB) (IH), Immobilized (HCB) + Air Insufflaction (HIA), AirInsufflaction (A), Oxygen (O), Oxygen + Immobilized HCB (OHI), Immobilized HCB +Oxygen20 (IHO20), Bioturbing (B), Bioturbing + Immobilized HCB (HIB).Analysis of hydrocarbons (GC-FID), TOC, structure of bacteria population (16S clonelibraries) and enumeration of total bacteria (DAPI count) were performed at the end ofexperimentation.