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Mechanistic study of antimonate reduction by Escherichia coli W3110.
Zhang, Lixin; Ye, Li; Yin, Zhipeng; Xiao, Kai; Jing, Chuanyong.
Afiliação
  • Zhang L; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
  • Ye L; School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China.
  • Yin Z; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
  • Xiao K; Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.
  • Jing C; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China; School of Environmental Science and Engineering, Shandong Univers
Environ Pollut ; 291: 118258, 2021 Dec 15.
Article em En | MEDLINE | ID: mdl-34606969
Microbial-assisted antimonate [Sb(V)] reduction immobilizes this redox-sensitive metalloid in the subsurface. Most indigenous aerobes in antimony (Sb)-contaminated areas do not contain Sb(V)-reducing genes but can resist high levels of Sb(V) threat. Herein, to unravel the mechanisms of Sb(V) resistance by aerobes, we used Escherichia coli W3110 as a model aerobe and incubated it with 10 µM Sb(V). We found that strain W3110, without known Sb(V)-reducing genes, was able to reduce Sb(V) to Sb(III). Our transcriptome analysis and reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) results show that the Sb(V) threat at the 10 µM level had a negligible effect on the gene expression of strain W3110. In vitro incubation experiments further indicate that Sb(V) reduction was attributable to extracellular polymeric substances (EPS). Moreover, the three-dimensional excitation-emission matrix fluorescence spectroscopy reveals that the tryptophan-like components in EPS were involved in Sb(V) binding as evidenced by its weakened fluorescence intensity upon Sb(V) addition. The FTIR and XPS analyses indicate that hemiacetal and amide groups in EPS contributed to the reduction of Sb(V). Preculture with 10 µM Sb(V) did not exhibit a significant difference in Sb(V)-reducing capacity, suggesting that Sb(V) stress probably did not stimulate EPS secretion of W3110. Our results highlight the importance of EPS as the first line of defense against toxins, especially for those bacteria without such functional genes.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Escherichia coli / Antimônio Idioma: En Ano de publicação: 2021 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Escherichia coli / Antimônio Idioma: En Ano de publicação: 2021 Tipo de documento: Article