title: [Biosynthesis of selemium nanobars by Shewallena oneidensis MR-1].
abstract: OBJECTIVE
  We used Shewallena oneidensis MR-1 to produce selemium (Se) nanobars and studied the influence of Se(IV) concentrations and incubation time on nanobars production.
  
  
  METHODS
  We incubated Shewallena oneidensis MR-1 under anaerobic condition with Luria-Bertani (LB) liquid medium containing 0.1, 1.0, 10.0 or 100.0 mmol/L Se (IV) in Na2SeO3, to determine the optimal Se (IV) concentration for bacterial growth. Then, we incubated Shewallena oneidensis MR-1 with the optimal Se (IV) concentration and collected deposits 24 and 72 h after anearobic incubation. We used scanning electron microscopy, energy-dispersive X-ray and X-ray diffraction to analyse the deposits.
  
  
  RESULTS
  The cross sectional diameter and length of deposits that were produced by Shewallena oneidensis MR-1 after 24 h incubation with 1 mmol/L Se(IV) was around 80 nm and 2-3 μm, respectively. However, the deposits after 72 h incubation exceeded the size limit of nano material. Furthermore, the energy-dispersive X-ray and the X-ray diffraction spectroscopy confirmed that the deposits were elemental Se.
  
  
  CONCLUSIONS
  This study provides a viable method for the biosynthesis of Se nanoban Shewallena oneidensis MR-1 can produce a large number of Se nanobars at exponential phase under 0.1 mmol/L Se (IV).
authors.forename: Huan
authors.initials: H
authors.lastname: Deng
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Zheng
authors.forename: Feng
authors.initials: F
authors.lastname: Zhao
mesh_terms: D008855:Microscopy, Electron, Scanning; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D012643:Selenium / Q000737:chemistry / Q000378:metabolism*; D020592:Shewanella / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D014961:X-Ray Diffraction
chemical_list: D012643:Selenium