title: Immobilization of Ochrobactrum tritici As5 on PTFE thin films for arsenite biofiltration.
abstract: Ochrobactrum tritici SCII24T bacteria is an environmental strain with high capacity to resist to arsenic (As) toxicity, which makes it able to grow in the presence of As(III). The inactivation of the two functional arsenite efflux pumps, ArsB and ACR3_1, resulted in the mutant O. tritici As5 exhibiting a high accumulation of arsenite. This work describes a method for the immobilization of the mutant cells O. tritici As5, on a commercial polymeric net after sputtered modified by the deposition of poly(tetrafluoroethylene) (PTFE) thin films, and demonstrates the capacity of immobilized cells to accumulate arsenic from solutions. Six different set of deposition parameters for PTFE thin films were developed and tested in vitro regarding their ability to immobilize the bacterial cells. The surface that exhibited a mild zeta potential value, hydrophobic characteristics, the lowest surface free energy but with a high polar component and the appropriate ratio of chemical reactive groups allowed cells to proliferate and to grow as a biofilm. These immobilized cells maintained their ability to accumulate the surrounding arsenite, making it a great arsenic biofilter to be used in bioremediation processes.
authors.affiliation: CEMUC - Department of Mechanical Engineering, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra, Portugal; Department of Life Sciences, University of Coimbra, 3001-401 Coimbra, Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Branco
authors.affiliation: Department of Life Sciences, University of Coimbra, 3001-401 Coimbra, Portugal.
authors.forename: Tânia
authors.initials: T
authors.lastname: Sousa
authors.affiliation: CEMUC - Department of Mechanical Engineering, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra, Portugal.
authors.forename: Ana P
authors.initials: AP
authors.lastname: Piedade
authors.affiliation: CEMUC - Department of Mechanical Engineering, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra, Portugal; Department of Life Sciences, University of Coimbra, 3001-401 Coimbra, Portugal. Electronic address: pvmorais@ci.uc.pt.
authors.forename: Paula V
authors.initials: PV
authors.lastname: Morais
mesh_terms: D018053:Arsenites / Q000378:metabolism*; D042041:Ochrobactrum / Q000378:metabolism*; D011108:Polymers; D011138:Polytetrafluoroethylene / Q000378:metabolism*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D018053:Arsenites; D011108:Polymers; D014874:Water Pollutants, Chemical; D011138:Polytetrafluoroethylene; C015001:arsenite
keywords: Arsenic bioaccumulation; Arsenic resistance; As(III) efflux pumps; Bacteria immobilization; Biotool; PTFE