Enhanced reduction of sulfate and chromium under sulfate-reducing condition by synergism between extracellular polymeric substances and graphene oxide

Jia Yan; Weizhuo Ye; Xiaoshan Liang; Siji Wang; Jiehui Xie; Kengqiang Zhong; Min Bao; Jinbin Yang; Huijun Wen; Shugeng Li; Yongheng Chen; Ji Dong Gu; Hongguo Zhang

doi:10.1016/j.envres.2020.109157

Enhanced reduction of sulfate and chromium under sulfate-reducing condition by synergism between extracellular polymeric substances and graphene oxide

Jia Yan, Weizhuo Ye, Xiaoshan Liang, Siji Wang, Jiehui Xie, Kengqiang Zhong, Min Bao, Jinbin Yang, Huijun Wen, Shugeng Li, Yongheng Chen, Ji Dong Gu, Hongguo Zhang^*

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

33 Scopus citations

Abstract

Microbial reduction of sulfate and metal were simultaneously enhanced in the presence of graphene oxide (GO)-like nanomaterials, however, the mechanism remained unclear. In this study, bio-reduction of Cr was compared between free-living bacterium BY7 and immobilized BY7 (BY-rGO) on reduced GO particles. The role of extracellular polymeric substances (EPS) and rGO material on reduction of sulfate and Cr was investigated. Cr(VI) was reduced to Cr(III) and elemental Cr by BY-rGO particles up to 51% and 28%, respectively. EPS produced by the bacterium BY7 mainly consisted of proteins, polysaccharides, nucleic acids and humic substances. Concentration of EPS was sharply increased (about 54%) with the addition of graphene oxide, while the composition of EPS components was strongly affected by the exposure to Cr. By removing surface EPS without breaking the cells, reduction activities of sulfate and chromium by both BY-rGO particles and free-living BY7 cells were decreased. In contrast, reduction of sulfate and Cr by the free-living BY7 cells was enhanced with external addition of extracted EPS. Based on electrochemical analysis, the reduction peak indicating enhanced electron transfer was lost after removing EPS. Moreover, the contribution of each EPS fractions on sulfate and Cr reduction followed an order of polysaccharides > proteins > humic substances. Therefore, microbial sulfate and Cr reduction processes in the presence of BY-rGO particles were enhanced by the increasing amounts of EPS, which likely mediated electron transfer during sulfate and Cr reduction, and relieved bacteria from metal toxicity. Nevertheless, the presence of rGO was crucially important for elemental Cr production under sulfate-reducing condition, which might contribute to lowering electric potential or reducing activation energy for Cr(III) reduction. This work provided direct evidences for enhancing sulfate and Cr reduction activities by supplement of EPS as an additive to increase treatment efficiency in environmental bioremediation.

Original language	English
Article number	109157
Journal	Environmental Research
Volume	183
DOIs	https://doi.org/10.1016/j.envres.2020.109157
State	Published - Apr 2020
Externally published	Yes

Keywords

Cr reduction
EPS
Electron transport
Reduced graphene oxide
Sulfate reduction

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10.1016/j.envres.2020.109157

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Yan, J., Ye, W., Liang, X., Wang, S., Xie, J., Zhong, K., Bao, M., Yang, J., Wen, H., Li, S., Chen, Y., Gu, J. D., & Zhang, H. (2020). Enhanced reduction of sulfate and chromium under sulfate-reducing condition by synergism between extracellular polymeric substances and graphene oxide. Environmental Research, 183, Article 109157. https://doi.org/10.1016/j.envres.2020.109157

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title = "Enhanced reduction of sulfate and chromium under sulfate-reducing condition by synergism between extracellular polymeric substances and graphene oxide",

abstract = "Microbial reduction of sulfate and metal were simultaneously enhanced in the presence of graphene oxide (GO)-like nanomaterials, however, the mechanism remained unclear. In this study, bio-reduction of Cr was compared between free-living bacterium BY7 and immobilized BY7 (BY-rGO) on reduced GO particles. The role of extracellular polymeric substances (EPS) and rGO material on reduction of sulfate and Cr was investigated. Cr(VI) was reduced to Cr(III) and elemental Cr by BY-rGO particles up to 51% and 28%, respectively. EPS produced by the bacterium BY7 mainly consisted of proteins, polysaccharides, nucleic acids and humic substances. Concentration of EPS was sharply increased (about 54%) with the addition of graphene oxide, while the composition of EPS components was strongly affected by the exposure to Cr. By removing surface EPS without breaking the cells, reduction activities of sulfate and chromium by both BY-rGO particles and free-living BY7 cells were decreased. In contrast, reduction of sulfate and Cr by the free-living BY7 cells was enhanced with external addition of extracted EPS. Based on electrochemical analysis, the reduction peak indicating enhanced electron transfer was lost after removing EPS. Moreover, the contribution of each EPS fractions on sulfate and Cr reduction followed an order of polysaccharides > proteins > humic substances. Therefore, microbial sulfate and Cr reduction processes in the presence of BY-rGO particles were enhanced by the increasing amounts of EPS, which likely mediated electron transfer during sulfate and Cr reduction, and relieved bacteria from metal toxicity. Nevertheless, the presence of rGO was crucially important for elemental Cr production under sulfate-reducing condition, which might contribute to lowering electric potential or reducing activation energy for Cr(III) reduction. This work provided direct evidences for enhancing sulfate and Cr reduction activities by supplement of EPS as an additive to increase treatment efficiency in environmental bioremediation.",

keywords = "Cr reduction, EPS, Electron transport, Reduced graphene oxide, Sulfate reduction",

author = "Jia Yan and Weizhuo Ye and Xiaoshan Liang and Siji Wang and Jiehui Xie and Kengqiang Zhong and Min Bao and Jinbin Yang and Huijun Wen and Shugeng Li and Yongheng Chen and Gu, {Ji Dong} and Hongguo Zhang",

note = "Publisher Copyright: {\textcopyright} 2020 Elsevier Inc.",

year = "2020",

month = apr,

doi = "10.1016/j.envres.2020.109157",

language = "英语",

volume = "183",

journal = "Environmental Research",

issn = "0013-9351",

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TY - JOUR

T1 - Enhanced reduction of sulfate and chromium under sulfate-reducing condition by synergism between extracellular polymeric substances and graphene oxide

AU - Yan, Jia

AU - Ye, Weizhuo

AU - Liang, Xiaoshan

AU - Wang, Siji

AU - Xie, Jiehui

AU - Zhong, Kengqiang

AU - Bao, Min

AU - Yang, Jinbin

AU - Wen, Huijun

AU - Li, Shugeng

AU - Chen, Yongheng

AU - Gu, Ji Dong

AU - Zhang, Hongguo

PY - 2020/4

Y1 - 2020/4

N2 - Microbial reduction of sulfate and metal were simultaneously enhanced in the presence of graphene oxide (GO)-like nanomaterials, however, the mechanism remained unclear. In this study, bio-reduction of Cr was compared between free-living bacterium BY7 and immobilized BY7 (BY-rGO) on reduced GO particles. The role of extracellular polymeric substances (EPS) and rGO material on reduction of sulfate and Cr was investigated. Cr(VI) was reduced to Cr(III) and elemental Cr by BY-rGO particles up to 51% and 28%, respectively. EPS produced by the bacterium BY7 mainly consisted of proteins, polysaccharides, nucleic acids and humic substances. Concentration of EPS was sharply increased (about 54%) with the addition of graphene oxide, while the composition of EPS components was strongly affected by the exposure to Cr. By removing surface EPS without breaking the cells, reduction activities of sulfate and chromium by both BY-rGO particles and free-living BY7 cells were decreased. In contrast, reduction of sulfate and Cr by the free-living BY7 cells was enhanced with external addition of extracted EPS. Based on electrochemical analysis, the reduction peak indicating enhanced electron transfer was lost after removing EPS. Moreover, the contribution of each EPS fractions on sulfate and Cr reduction followed an order of polysaccharides > proteins > humic substances. Therefore, microbial sulfate and Cr reduction processes in the presence of BY-rGO particles were enhanced by the increasing amounts of EPS, which likely mediated electron transfer during sulfate and Cr reduction, and relieved bacteria from metal toxicity. Nevertheless, the presence of rGO was crucially important for elemental Cr production under sulfate-reducing condition, which might contribute to lowering electric potential or reducing activation energy for Cr(III) reduction. This work provided direct evidences for enhancing sulfate and Cr reduction activities by supplement of EPS as an additive to increase treatment efficiency in environmental bioremediation.

AB - Microbial reduction of sulfate and metal were simultaneously enhanced in the presence of graphene oxide (GO)-like nanomaterials, however, the mechanism remained unclear. In this study, bio-reduction of Cr was compared between free-living bacterium BY7 and immobilized BY7 (BY-rGO) on reduced GO particles. The role of extracellular polymeric substances (EPS) and rGO material on reduction of sulfate and Cr was investigated. Cr(VI) was reduced to Cr(III) and elemental Cr by BY-rGO particles up to 51% and 28%, respectively. EPS produced by the bacterium BY7 mainly consisted of proteins, polysaccharides, nucleic acids and humic substances. Concentration of EPS was sharply increased (about 54%) with the addition of graphene oxide, while the composition of EPS components was strongly affected by the exposure to Cr. By removing surface EPS without breaking the cells, reduction activities of sulfate and chromium by both BY-rGO particles and free-living BY7 cells were decreased. In contrast, reduction of sulfate and Cr by the free-living BY7 cells was enhanced with external addition of extracted EPS. Based on electrochemical analysis, the reduction peak indicating enhanced electron transfer was lost after removing EPS. Moreover, the contribution of each EPS fractions on sulfate and Cr reduction followed an order of polysaccharides > proteins > humic substances. Therefore, microbial sulfate and Cr reduction processes in the presence of BY-rGO particles were enhanced by the increasing amounts of EPS, which likely mediated electron transfer during sulfate and Cr reduction, and relieved bacteria from metal toxicity. Nevertheless, the presence of rGO was crucially important for elemental Cr production under sulfate-reducing condition, which might contribute to lowering electric potential or reducing activation energy for Cr(III) reduction. This work provided direct evidences for enhancing sulfate and Cr reduction activities by supplement of EPS as an additive to increase treatment efficiency in environmental bioremediation.

KW - Cr reduction

KW - EPS

KW - Electron transport

KW - Reduced graphene oxide

KW - Sulfate reduction

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U2 - 10.1016/j.envres.2020.109157

DO - 10.1016/j.envres.2020.109157

M3 - 文章

C2 - 32006768

AN - SCOPUS:85078466765

SN - 0013-9351

VL - 183

JO - Environmental Research

JF - Environmental Research

M1 - 109157

ER -

Enhanced reduction of sulfate and chromium under sulfate-reducing condition by synergism between extracellular polymeric substances and graphene oxide

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