title: Biotransformation of hexavalent chromium into extracellular chromium(III) oxide nanoparticles using Schwanniomyces occidentalis.
abstract: OBJECTIVE
  To demonstrate biotransformation of toxic Cr(VI) ions into Cr2O3 nanoparticles by the yeast Schwanniomyces occidentalis.
  
  
  RESULTS
  Reaction mixtures containing S. occidentalis NCIM 3459 and Cr(VI) ions that were initially yellow turned green after 48 h incubation. The coloration was due to the synthesis of chromium (III) oxide nanoparticles (Cr2O3NPs). UV-Visible spectra of the reaction mixtures showed peaks at 445 and 600 nm indicating (4)A2g → (4)T1g and (4)A2g → (4)T2g transitions in Cr2O3, respectively. FTIR profiles suggested the involvement of carboxyl and amide groups in nanoparticle synthesis and stabilization. The Cr2O3NPs ranged between 10 and 60 nm. Their crystalline nature was evident from the selective area electron diffraction and X-ray diffraction patterns. Energy dispersive spectra confirmed the chemical composition of the nanoparticles. These biogenic nanoparticles could find applications in different fields.
  
  
  CONCLUSIONS
  S. occidentalis mediated biotransformation of toxic Cr(VI) ions into crystalline extracellular Cr2O3NPs under benign conditions.
authors.affiliation: Institute of Bioinformatics and Biotechnology, Savitribai Phule Pune University, Pune, 411007, India.
authors.forename: Pallavi T
authors.initials: PT
authors.lastname: Mohite
authors.affiliation: Institute of Bioinformatics and Biotechnology, Savitribai Phule Pune University, Pune, 411007, India.
authors.forename: Ameeta Ravi
authors.initials: AR
authors.lastname: Kumar
authors.affiliation: Institute of Bioinformatics and Biotechnology, Savitribai Phule Pune University, Pune, 411007, India. smita@unipune.ac.in.
authors.forename: Smita S
authors.initials: SS
authors.lastname: Zinjarde
mesh_terms: D001711:Biotransformation; D002857:Chromium / Q000378:metabolism*; D017608:Chromium Compounds / Q000378:metabolism*; D003116:Color; D004785:Environmental Pollutants / Q000378:metabolism*; D053758:Nanoparticles / Q000378:metabolism*; D004718:Saccharomycetales / Q000378:metabolism*; D013053:Spectrophotometry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D017608:Chromium Compounds; D004785:Environmental Pollutants; D002857:Chromium; C074702:chromium hexavalent ion; C023600:chromic oxide
keywords: Cr2O3 nanoparticles; Hexavalent chromium biotransformation; Schwanniomyces occidentalis