Phosphatase-mediated bioprecipitation of lead by soil fungi

Xinjin Liang, Martin Kierans, Andrea Ceci, Stephen Hillier, Geoffrey Michael Gadd (Lead / Corresponding author)

Research output: Contribution to journalArticle

29 Citations (Scopus)
399 Downloads (Pure)

Abstract

Geoactive soil fungi were examined for their ability to release inorganic phosphate (Pi ) and mediate lead bioprecipitation during growth on organic phosphate substrates. Aspergillus niger and Paecilomyces javanicus grew in 5 mM Pb(NO3)2-containing media amended with glycerol 2-phosphate (G2P) or phytic acid (PyA) as sole P sources, and liberated Pi into the medium. This resulted in almost complete removal of Pb from solution and extensive precipitation of lead-containing minerals around the biomass, confirming the importance of the mycelium as a reactive network for biomineralization. The minerals were identified as pyromorphite (Pb5(PO4)3Cl), only produced by P. javanicus, and lead oxalate (PbC2O4), produced by A. niger and P. javanicus. Geochemical modelling of lead and lead mineral speciation as a function of pH and oxalate closely correlated with experimental conditions and data. Two main lead biomineralization mechanisms were therefore distinguished: pyromorphite formation depending on organic phosphate hydrolysis and lead oxalate formation depending on oxalate excretion. This also indicated species specificity in biomineralization depending on nutrition and physiology. Our findings provide further understanding of lead geomycology and organic phosphates as a biomineralization substrate, and are also relevant to metal immobilization biotechnologies for bioremediation, metal and P biorecovery, and utilization of waste organic phosphates.

Original languageEnglish
Pages (from-to)219-231
Number of pages13
JournalEnvironmental Microbiology
Volume18
Issue number1
Early online date3 Sep 2015
DOIs
Publication statusPublished - Jan 2016

Keywords

  • Aspergillus niger
  • Biochemical processes
  • Biodegradation, Environmental
  • Glycerophosphates
  • Hypocreales
  • Lead
  • Minerals
  • Nitrates
  • Oxalates
  • Phosphates
  • Phosphoric Monoester Hydrolases
  • Phytic acid
  • Soil
  • Soil microbiology
  • Journal article
  • Research support, Non-U.S. Gov't

Fingerprint Dive into the research topics of 'Phosphatase-mediated bioprecipitation of lead by soil fungi'. Together they form a unique fingerprint.

  • Projects

    Profiles

    No photo of Geoffrey Michael Gadd

    Gadd , Geoffrey Michael

    Person: Academic

    Cite this