One step bioconversion of waste precious metals into Serratia biofilm-immobilized catalyst for Cr(VI) reduction

P. Yong, W. Liu, Z. Zhang, D. Beauregard, M. L. Johns, L. E. Macaskie*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


Objectives: For reduction of Cr(VI) the Pd-catalyst is excellent but costly. The objectives were to prove the robustness of a Serratia biofilm as a support for biogenic Pd-nanoparticles and to fabricate effective catalyst from precious metal waste. Results: Nanoparticles (NPs) of palladium were immobilized on polyurethane reticulated foam and polypropylene supports via adhesive biofilm of a Serratia sp. The biofilm adhesion and cohesion strength were unaffected by palladization and catalytic biofilm integrity was also shown by magnetic resonance imaging. Biofilm-Pd and mixed precious metals on biofilm (biofilm-PM) reduced 5 mM Cr(VI) to Cr(III) when immobilized in a flow-through column reactor, at respective flow rates of 9 and 6 ml/h. The lower activity of the latter was attributed to fewer, larger, metal deposits on the bacteria. Activity was lost in each case at pH 7 but was restored by washing with 5 mM citrate solution or by exposure of columns to solution at pH 2, suggesting fouling by Cr(III) hydroxide product at neutral pH. Conclusion: A ‘one pot’ conversion of precious metal waste into new catalyst for waste decontamination was shown in a continuous flow system based on the use of Serratia biofilm to manufacture and support catalytic Pd-nanoparticles.

Original languageEnglish
Pages (from-to)2181-2191
Number of pages11
JournalBiotechnology Letters
Issue number11
Publication statusPublished - 29 Nov 2015


  • Biofilm
  • Catalyst
  • Chromate reduction
  • Palladium
  • Precious metals
  • Serratia sp

ASJC Scopus subject areas

  • Biotechnology


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