title: Biogenic formation of As-S nanotubes by diverse Shewanella strains.
abstract: Shewanella sp. strain HN-41 was previously shown to produce novel, photoactive, As-S nanotubes via the reduction of As(V) and S(2)O(3)(2-) under anaerobic conditions. To determine if this ability was unique to this bacterium, 10 different Shewanella strains, including Shewanella sp. strain HN-41, Shewanella sp. strain PV-4, Shewanella alga BrY, Shewanella amazonensis SB2B, Shewanella denitrificans OS217, Shewanella oneidensis MR-1, Shewanella putrefaciens CN-32, S. putrefaciens IR-1, S. putrefaciens SP200, and S. putrefaciens W3-6-1, were examined for production of As-S nanotubes under standardized conditions. Of the 10 strains examined, three formed As-S nanotubes like those of strain HN-41. While Shewanella sp. strain HN-41 and S. putrefaciens CN-32 rapidly formed As-S precipitates in 7 days, strains S. alga BrY and S. oneidensis MR-1 reduced As(V) at a much lower rate and formed yellow As-S after 30 days. Electron microscopy, energy-dispersive X-ray spectroscopy, and extended X-ray absorption fine-structure spectroscopy analyses showed that the morphological and chemical properties of As-S formed by strains S. putrefaciens CN-32, S. alga BrY, and S. oneidensis MR-1 were similar to those previously determined for Shewanella sp. strain HN-41 As-S nanotubes. These studies indicated that the formation of As-S nanotubes is widespread among Shewanella strains and is closely related to bacterial growth and the reduction rate of As(V) and thiosulfate.
authors.affiliation: Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea.
authors.forename: Shenghua
authors.initials: S
authors.lastname: Jiang
authors.forename: Ji-Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: Min-Gyu
authors.initials: MG
authors.lastname: Kim
authors.forename: Nosang V
authors.initials: NV
authors.lastname: Myung
authors.forename: James K
authors.initials: JK
authors.lastname: Fredrickson
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Sadowsky
authors.forename: Hor-Gil
authors.initials: HG
authors.lastname: Hur
mesh_terms: D001152:Arsenicals / Q000378:metabolism*; D008854:Microscopy, Electron; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D020592:Shewanella / Q000378:metabolism*; D013052:Spectrometry, X-Ray Emission; D013440:Sulfides / Q000378:metabolism*; D056928:X-Ray Absorption Spectroscopy
chemical_list: D001152:Arsenicals; D013440:Sulfides; C045816:arsenic trisulfide