title: Laser spectroscopic studies of interactions of UVI with bacterial phosphate species.
abstract: We have investigated the interactions of UVI with two bacterial phosphate-containing species: Gram-positive Bacillus sphaericus and Gram-negative Pseudomonas aeruginosa. The Gram-positive B. sphaericus was investigated by using Raman spectroscopy and time-resolved laser-induced fluorescence spectroscopy (TRLFS). We found that living cells, spores, and intact heat-killed cells complexed UVI (pH 4.5) through phosphate groups bound to their surfaces, while decomposed cells released H2PO4- and precipitated UVI as UO2(H2PO4)2. TRLFS of UVI showed that Gram-negative P. aeruginosa--genetically engineered to accumulate polyphosphate, subsequently degrade it, and secrete phosphate--precipitated UVI quantitatively at pH 4.5. The same bacterial strain, not induced to secrete phosphate, sorbed only a small amount of UVI.
authors.affiliation: Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA 94720, USA.
authors.forename: Roger
authors.initials: R
authors.lastname: Knopp
authors.forename: Petra J
authors.initials: PJ
authors.lastname: Panak
authors.forename: Lewis A
authors.initials: LA
authors.lastname: Wray
authors.forename: Neil S
authors.initials: NS
authors.lastname: Renninger
authors.forename: Jay D
authors.initials: JD
authors.lastname: Keasling
authors.forename: Heino
authors.initials: H
authors.lastname: Nitsche
mesh_terms: D001407:Bacillus / Q000378:metabolism*; D010755:Organophosphates / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013059:Spectrum Analysis, Raman; D014501:Uranium / Q000378:metabolism*; D014871:Water Microbiology
chemical_list: D010755:Organophosphates; D014501:Uranium