title: Selenite biotransformation and detoxification by Stenotrophomonas maltophilia SeITE02: Novel clues on the route to bacterial biogenesis of selenium nanoparticles.
abstract: A putative biosynthetic mechanism for selenium nanoparticles (SeNPs) and efficient reduction of selenite (SeO32-) in the bacterial strain Stenotrophomonas maltophilia SeITE02 are addressed here on the basis of information gained by a combined approach relying on a set of physiological, chemical/biochemical, microscopy, and proteomic analyses. S. maltophilia SeITE02 is demonstrated to efficiently transform selenite into elemental selenium (Se°) by reducing 100% of 0.5mM of this toxic oxyanion to Se° nanoparticles within 48h growth, in liquid medium. Since the selenite reducing activity was detected in the cytoplasmic protein fraction, while biogenic SeNPs showed mainly extracellular localization, a releasing mechanism of SeNPs from the intracellular environment is hypothesized. SeNPs appeared spherical in shape and with size ranging from 160nm to 250nm, depending on the age of the cultures. Proteomic analysis carried out on the cytoplasmic fraction identified an alcohol dehydrogenase homolog, conceivably correlated with the biogenesis of SeNPs. Finally, by Fourier Transformed Infrared Spectrometry, protein and lipid residues were detected on the surface of biogenic SeNPs. Eventually, this strain might be efficaciously exploited for the remediation of selenite-contaminated environmental matrices due to its high SeO32-reducing efficiency. Biogenic SeNPs may also be considered for technological applications in different fields.
authors.affiliation: Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy. Electronic address: silvia.lampis@univr.it.
authors.forename: Silvia
authors.initials: S
authors.lastname: Lampis
authors.affiliation: Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Zonaro
authors.affiliation: Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy; Biosciences, College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.
authors.forename: Cristina
authors.initials: C
authors.lastname: Bertolini
authors.affiliation: Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Cecconi
authors.affiliation: Department of Computer Science, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Monti
authors.affiliation: Biosciences, College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.
authors.forename: Massimo
authors.initials: M
authors.lastname: Micaroni
authors.affiliation: Biofilm Research Group, Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Turner
authors.affiliation: Biosciences, College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.
authors.forename: Clive S
authors.initials: CS
authors.lastname: Butler
authors.affiliation: Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Vallini
mesh_terms: D000426:Alcohol Dehydrogenase / Q000737:chemistry / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification; D001673:Biodegradation, Environmental; D002384:Catalysis; D053758:Nanoparticles / Q000378:metabolism; D010084:Oxidation-Reduction; D010316:Particle Size; D040901:Proteomics; D020887:Selenious Acid / Q000737:chemistry*; D020615:Stenotrophomonas maltophilia / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D000426:Alcohol Dehydrogenase; D020887:Selenious Acid
keywords: Alcohol dehydrogenase; Biogenic selenium nanoparticles; Bioremediation; Selenite reduction; Stenotrophomonas maltophilia SeITE02