A genomic perspective of metal-resistant bacteria from gold particles: Possible survival mechanisms during gold biogeochemical cycling

Santonu Kumar Sanyal, Frank Reith, Jeremiah Shuster

Research output: Contribution to journalArticleResearchpeer-review

12 Citations (Scopus)

Abstract

A bacterial consortium was enriched from gold particles that 'experienced' ca. 80 years of biotransformation within waste-rock piles (Australia). This bacterial consortium was exposed to 10 μM AuCl3 to obtain Au-tolerant bacteria. From these isolates, Serratia sp. and Stenotrophomonas sp. were the most Au-tolerant and reduced soluble Au as pure gold nanoparticles, indicating that passive mineralisation is a mechanism for mediating the toxic effect of soluble Au produced during particle dissolution. Genome-wide analysis demonstrated that these isolates also possessed various genes that could provide cellular defence enabling survival under heavy-metal stressed condition by mediating the toxicity of heavy metals through active efflux/reduction. Diverse metal-resistant genes or genes clusters (cop, cus, czc, znt and ars) were detected, which could confer resistance to soluble Au. Comparative genome analysis revealed that the majority of detected heavy-metal resistant genes were similar (i.e. orthologous) to those genes of Cupriavidus metallidurans CH34. The detection of heavy-metal resistance, nutrient cycling and biofilm formation genes (pgaABCD, bsmA and hmpS) may have indirect yet important roles when dealing with soluble Au during particle dissolution. In conclusion, the physiological and genomic results suggest that bacteria living on gold particles would likely use various genes to ensure survival during Au-biogeochemical cycling.

Original languageEnglish
Article numberFIAA111
Number of pages15
JournalFEMS Microbiology Ecology
Volume96
Issue number7
DOIs
Publication statusPublished - Jul 2020
Externally publishedYes

Keywords

  • Au-tolerant bacteria
  • Gold biogeochemical cycling
  • Gold biogeochemistry
  • Gold particles
  • Heavy-metal resistance
  • Serratia
  • Stenotrophomonas

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