The Diversity and Function of Bacteria Enriched from Gold Particles: Understanding Bacterial Contribution to Biogeochemical Cycling of Gold
type: CreativeWork
description: In natural environments, gold is dissolved (oxidized), dispersed, and reconcentrated (reduced and aggregated). Collectively, these processes constitute the biogeochemical cycle of gold, which can be catalysed by bacteria, and have been interpreted from the characterisation of gold particles that have undergone (bio)transformation. Therefore, the primary focus of this study is to explore the diversity and function of bacteria residing on gold particles to understand their influence on particle structure and chemistry and hence gold biogeochemical cycling. In doing so, both culture-independent (direct amplification of bacterial 16S rDNA gene from particles) and dependent (enrichment of viable bacteria from particles) techniques were applied to get a comprehensive overview of the composition of microbial communities on gold particles. Diverse bacterial species belonging to different phyla were detected on gold particles, which was consistent with previous studies. The culture-independent approach provided a record of both past and present bacterial existence on gold particles, whereas, the culture-dependent approach enriched viable bacteria living on gold particles at the time of sampling. The detection and enrichment of bacteria from gold particles indicated that on Earth’s surficial environment gold particles could provide a solid substrate for bacterial colonisation. The biochemical activity of these bacteria, along with other environmental conditions, create microenvironments on gold particle surfaces (i.e. polymorphic layers) which promote particle biotransformation. The microstructures (porous textures and pure gold nanoparticles) on gold particle surfaces were interpreted as “products” of past biogeochemical processes (gold dissolution and precipitation). By analysing gold particle structure, chemistry and secondary gold concentration in the soil, gold biogeochemical cycling was estimated to be 1.60 × 10-9 M year-1 and was attributed, in part, to the viable bact…
abstract: In natural environments, gold is dissolved (oxidized), dispersed, and reconcentrated (reduced and aggregated). Collectively, these processes constitute the biogeochemical cycle of gold, which can be catalysed by bacteria, and have been interpreted from the characterisation of gold particles that have undergone (bio)transformation. Therefore, the primary focus of this study is to explore the diversity and function of bacteria residing on gold particles to understand their influence on particle structure and chemistry and hence gold biogeochemical cycling. In doing so, both culture-independent (direct amplification of bacterial 16S rDNA gene from particles) and dependent (enrichment of viable bacteria from particles) techniques were applied to get a comprehensive overview of the composition of microbial communities on gold particles. Diverse bacterial species belonging to different phyla were detected on gold particles, which was consistent with previous studies. The culture-independent approach provided a record of both past and present bacterial existence on gold particles, whereas, the culture-dependent approach enriched viable bacteria living on gold particles at the time of sampling. The detection and enrichment of bacteria from gold particles indicated that on Earth’s surficial environment gold particles could provide a solid substrate for bacterial colonisation. The biochemical activity of these bacteria, along with other environmental conditions, create microenvironments on gold particle surfaces (i.e. polymorphic layers) which promote particle biotransformation. The microstructures (porous textures and pure gold nanoparticles) on gold particle surfaces were interpreted as “products” of past biogeochemical processes (gold dissolution and precipitation). By analysing gold particle structure, chemistry and secondary gold concentration in the soil, gold biogeochemical cycling was estimated to be 1.60 × 10-9 M year-1 and was attributed, in part, to the viable bact…
author: Sanyal, Santonu Kumar
language: en
keywords: Gold, biogeochemical cycling, gold particle, bacterial diversity, biochemistry, Au-tolerant bacterial genome and function, mercury contamination & geomicrobiology
date published: 2020
date modified: 2026-07-24T00:50:44Z
provider: University of Adelaide
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Adelaide

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2440/126539