Extracellular Saccharide-Mediated Reduction of Au3+ to Gold   Nanoparticles: New Insights for Heavy Metals Biomineralization on   Microbial Surfaces

doi:10.1021/acs.est.6b05930

CORC > 北京大学 > 城市与环境学院

	Extracellular Saccharide-Mediated Reduction of Au3+ to Gold Nanoparticles: New Insights for Heavy Metals Biomineralization on Microbial Surfaces
	Kang, Fuxing ; Qu, Xiaolei ; Alvarez, Pedro J. J. ; Zhu, Dongqiang
刊名	ENVIRONMENTAL SCIENCE & TECHNOLOGY
	2017
关键词	DISSOLVED ORGANIC-MATTER POLYMERIC SUBSTANCES REDUCING BACTERIA BIOFILM MATRIX SPECTROSCOPY PLANTS IRON ACCUMULATION MECHANISM BIOMASS
DOI	10.1021/acs.est.6b05930
英文摘要	Biomineralization is a critical process controlling the biogeochemical cycling, fate, and potential environmental impacts of heavy metals. Despite the indispensability of extracellular polymeric substances (EPS) to microbial life and their ubiquity in soil and aquatic environments, the role played by EPS in the transformation and biomineralization of heavy metals is not well understood. Here, we used gold ion (Au3+) as a model heavy metal ion to quantitatively assess the role of EPS in biomineralization and discern the responsible functional groups. Integrated spectroscopic analyses showed that Au(3+)was readily reduced to zerovalent gold nanoparticles (AuNPs, 2-15 nm in size) in aqueous suspension of Escherichia coli or dissolved EPS extracted from microbes. The majority of AuNPs (95.2%) was formed outside Escherichia coli cells, and the removal of EPS attached to cells pronouncedly suppressed Au3+ reduction, reflecting the predominance of the extracellular matrix in Au3+ reduction. XPS, UV-vis, and FTIR analyses corroborated that Au3+ reduction was mediated by the hemiacetal groups (aldehyde equivalents) of reducing saccharides of EPS. Consistently, the kinetics of AuNP formation obeyed pseudo-second -order reaction kinetics with respect to the concentrations of Au3+ and the hemiacetal groups in EPS, with minimal dependency on the source of microbial EPS. Our findings indicate a previously overlooked, universally significant contribution of EPS to the reduction, mineralization, and potential detoxification of metal species with high oxidation state.; National Key Basic Research Program of China [2014CB441103]; National Natural Science Foundation of China [21237002, 21225729, 21428701, 41401543, 2014M561662]; National Science Foundation for Postdoctoral Scientists of China [2014M561662]; Natural Science Foundation of Jiangsu Province of China [BK20140725]; Fundamental Research Funds for the Central Universities [KJQN201518]; NSF Engineering Research Center on Nanotechnology-Enabled Water Treatment [EEC-1449500]; SCI(E); ARTICLE; 5; 2776-2785; 51
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/474650]
专题	城市与环境学院
推荐引用方式 GB/T 7714	Kang, Fuxing,Qu, Xiaolei,Alvarez, Pedro J. J.,et al. Extracellular Saccharide-Mediated Reduction of Au3+ to Gold Nanoparticles: New Insights for Heavy Metals Biomineralization on Microbial Surfaces[J]. ENVIRONMENTAL SCIENCE & TECHNOLOGY,2017.
APA	Kang, Fuxing,Qu, Xiaolei,Alvarez, Pedro J. J.,&Zhu, Dongqiang.(2017).Extracellular Saccharide-Mediated Reduction of Au3+ to Gold Nanoparticles: New Insights for Heavy Metals Biomineralization on Microbial Surfaces.ENVIRONMENTAL SCIENCE & TECHNOLOGY.
MLA	Kang, Fuxing,et al."Extracellular Saccharide-Mediated Reduction of Au3+ to Gold Nanoparticles: New Insights for Heavy Metals Biomineralization on Microbial Surfaces".ENVIRONMENTAL SCIENCE & TECHNOLOGY (2017).