| Title | Impact of bacterial motility on biosorption and cometabolism of pyrene in a porous medium |
| Abstract | The risks of pollution by polycyclic aromatic hydrocarbons (PAHs)may increase in bioremediated soils as a result of the formation of toxic byproducts and the mobilization of pollutants associated to suspended colloids. In this study, we used the motile and chemotactic bacterium Pseudomonas putida G7 as an experimental model for examining the potential role of bacterial motility in the cometabolism and biosorption of pyrene in a porous medium. For this purpose, we conducted batch and column transport experiments with 14C-labelled pyrene loaded on silicone O-rings, which acted as a passive dosing system. In the batch experiments, we observed concentrations
of the 14C-pyrene equivalentswell above the equilibrium concentration observed in abiotic controls. This mobilization was attributed to biosorption and cometabolism processes occurring in parallel. HPLC quantification revealed pyrene concentrations well below the 14C-based quantifications by liquid scintillation, indicating pyrene transformation into water-soluble polarmetabolites. The results from transport experiments in sand columns revealed that cometabolic-active, motile cells were capable of accessing a distant source of sorbed
pyrene. Using the same experimental system, we also determined that salicylate-mobilized cells, inhibited for pyrene cometabolism, but mobilized due to their tactic behavior, were able to sorb the compound and mobilize it by biosorption. Our results indicate that motile bacteria active in bioremediation may contribute, through cometabolism and biosorption, to the risk associated to pollutant mobilization in soils. This research could be the starting point for the development ofmore efficient, low-risk bioremediation strategies of poorly bioavailable contaminants in soils. |
| Source | Science of the total environment 717 |
| Keywords | PAHBioremediationBiosorptionRiskMotiliyBacteria |
| Journal | Science of the total environment |
| Editor | Elsevier, Lausanne ;, Paesi Bassi |
| Year | 2020 |
| Type | Articolo in rivista |
| DOI | 10.1016/j.scitotenv.2020.137210 |
| Authors | Rolando L, Vila J, Posada Baquero R Castilla-Alcantara JC, Barra Caracciolo A, Ortega-Calvo JJ |
| Text | 417004 2020 10.1016/j.scitotenv.2020.137210 PAH Bioremediation Biosorption Risk Motiliy Bacteria Impact of bacterial motility on biosorption and cometabolism of pyrene in a porous medium Rolando L, Vila J, Posada Baquero R Castilla Alcantara JC, Barra Caracciolo A, Ortega Calvo JJ Istituto di Ricerca Sulle Acque IRSA , CNR, Via Salaria km 29.300, 00015 Monterotondo Scalo, RM, Italy b Dipartimento di Science Ecologiche e Biologiche DEB , Universita degli studi della Tuscia, Via San Camillo de Lellis, 01100 Viterbo, Italy c Departament de Microbiologia, Universitat de Barcelona, Avenida Diagonal 643, 08028 Barcelona, Spain d Instituto de Recursos Naturales y Agrobiologia de Sevilla IRNAS , CSIC, Avenida Reina Mercedes, 10, E 41012 Seville, Spain The risks of pollution by polycyclic aromatic hydrocarbons PAHs may increase in bioremediated soils as a result of the formation of toxic byproducts and the mobilization of pollutants associated to suspended colloids. In this study, we used the motile and chemotactic bacterium Pseudomonas putida G7 as an experimental model for examining the potential role of bacterial motility in the cometabolism and biosorption of pyrene in a porous medium. For this purpose, we conducted batch and column transport experiments with 14C labelled pyrene loaded on silicone O rings, which acted as a passive dosing system. In the batch experiments, we observed concentrations of the 14C pyrene equivalentswell above the equilibrium concentration observed in abiotic controls. This mobilization was attributed to biosorption and cometabolism processes occurring in parallel. HPLC quantification revealed pyrene concentrations well below the 14C based quantifications by liquid scintillation, indicating pyrene transformation into water soluble polarmetabolites. The results from transport experiments in sand columns revealed that cometabolic active, motile cells were capable of accessing a distant source of sorbed pyrene. Using the same experimental system, we also determined that salicylate mobilized cells, inhibited for pyrene cometabolism, but mobilized due to their tactic behavior, were able to sorb the compound and mobilize it by biosorption. Our results indicate that motile bacteria active in bioremediation may contribute, through cometabolism and biosorption, to the risk associated to pollutant mobilization in soils. This research could be the starting point for the development ofmore efficient, low risk bioremediation strategies of poorly bioavailable contaminants in soils. 717 Postprint 07/02/2020 Impact of bacterial motility on biosorption and cometabolism of pyrene in a porous medium on line version Stoten2020_BacterialMotility.pdf Articolo in rivista Elsevier 0048 9697 Science of the total environment Science of the total environment Sci. total environ. anna.barracaracciolo BARRA CARACCIOLO ANNA |
