Optimization of cultural conditions of Arthrobacter sp. Sphe3 for growth-associated chromate(VI) reduction in free and immobilized cell systems.

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  • Additional Information
    • Source:
      Publisher: Elsevier Science Ltd Country of Publication: England NLM ID: 0320657 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1879-1298 (Electronic) Linking ISSN: 00456535 NLM ISO Abbreviation: Chemosphere Subsets: MEDLINE
    • Publication Information:
      Publication: Oxford : Elsevier Science Ltd
      Original Publication: Oxford, New York, : Pergamon Press.
    • Subject Terms:
      Arthrobacter/*metabolism ; Chromates/*metabolism; Alginates ; Arthrobacter/growth & development ; Biomass ; Biotransformation ; Cells, Immobilized/metabolism ; Chromium/metabolism ; Culture Media ; Glucuronic Acid ; Hexuronic Acids
    • Abstract:
      The current study aimed to characterize Arthrobacter sp. Sphe3 ability to reduce Cr(VI) in suspended cell cultures as well as in immobilized form using Ca-alginate beads. Adaptation studies in the presence of 5 mg L(-1) Cr(VI) showed a significant increase in specific growth rate from 0.25 to 0.3 h(-1) and bioremoval percentage from 64% to 94% (p<0.05), whereas Arthrobacter sp. Sphe3 could tolerate up to 50 mg L(-1) Cr(VI). Optimization of culture conditions resulted in complete reduction of 45 mg L(-1) Cr(VI) at 30 °C, pH 8 and 10 g L(-1) of glucose. High glucose concentrations helped at reducing (80±2.4)% of initial 100 mg L(-1) Cr(VI), whereas the bacterial strain could tolerate 850 mg L(-1) Cr(VI). Cr(III) formation was first evidenced by the appearance of a green insoluble precipitate in the medium. Cell biomass was successfully immobilized in Ca-alginate beads that were evaluated for their stability. Cell release was sharply decreased when 4% Na-alginate was used under non-shaking conditions. Biotransformation efficiency was enhanced when 25-50 mg cells mL(-1) Na-alginate from the exponential growth phase were collected and co-encapsulated with either 1% glucose and 0.5% (NH4)2SO4, or 1% LB medium. Immobilized biocatalyst could be reused up to 6 continuous cycles in the presence of 10 mg L(-1) Cr(VI), but its performance was lowered at higher metal concentrations comparing with free cells that significantly maintained their reducing ability up to 300 mg L(-1) Cr(VI).
      (Copyright © 2013. Published by Elsevier Ltd.)
    • Contributed Indexing:
      Keywords: Alginate; Arthrobacter; Bioreduction; Chromium; Immobilization
    • Accession Number:
      0 (Alginates)
      0 (Chromates)
      0 (Culture Media)
      0 (Hexuronic Acids)
      0R0008Q3JB (Chromium)
      8A5D83Q4RW (Glucuronic Acid)
    • Publication Date:
      Date Created: 20131105 Date Completed: 20140828 Latest Revision: 20181202
    • Publication Date:
      20231215
    • Accession Number:
      10.1016/j.chemosphere.2013.09.112
    • Accession Number:
      24183628