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Title:
The role of extracellular polymeric substances in bacterial cell surfaces and environmental pollutant redox transformation |
Abstract:
Organic and inorganic pollutant contamination in aquatic systems is a worldwide environmental issue. Priority environmental concerns include inorganic arsenic, selenium, and organic chlorinated aliphatic hydrocarbons. Microorganisms (bacteria, cyanobacteria, and microalgae) create significant amounts of extracellular polymeric substances (EPS) as a biological defense in a variety of environments. Cumulative data demonstrates that EPS has a role in regulating the amount of dissolved organic carbon and holds promising potential for the treatment of environmental pollutants. In this study, we demonstrate that common bacteria, cyanobacteria, and microalgae can convert inorganic arsenate, selenate, and organic chlorinated aliphatic hydrocarbon hexachloroethane (HCE) into arsenite and selenium nanoparticles, as well as tetrachloroethylene. This conversion occurs on the surfaces of the cell or in the dissolved extracellular polymeric substances (EPS) in the aqueous environment.The removal of EPS resulted in a reduction in the effectiveness of microbial cells to undergo redox transformation of inorganic and organic pollutants while enhancing intracellular absorption. The majority of reduced organic and inorganic contaminants originated from either the cell surface or the aqueous media.
This highlights the function of EPS as an organic component that reduces substances at the surfaces of microorganisms and acts as a protective barrier. Fourier-transform infrared (FTIR), cyclic voltammetry (CV), and other chemical tests have revealed certain molecules of low molecular weight as electron donors and electron transfer mediators in both organic and inorganic contaminants when dissolved EPS is present.The findings suggest that EPS acts as a barrier that reduces and protects cellular access of environmental pollutants to microbial cells. The findings of this study might have important implications in road mappingthe EPS-based biotechnologies for the remediation and recovery of organic and inorganic pollutants.
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Biography:
Dr. Sadiq Naveed works as a postdoctoral fellow at the Chinese Academy of Sciences' Institute of Urban Environment in Xiamen. Dr. Sadiq received his Ph.D. in Environmental Biology from Nanjing Agricultural University in Nanjing, China, in 2020 and served as a Boya Postdoctoral Fellow at Peking University in Beijing, China, from 2021 to 2023. He has been the primary author on seven manuscripts and co-author on six, all of which have been published in well-known peer-reviewed journals in his field and have received over 300 citations. He has served as a reviewer for several peer-reviewed journals, including Environmental Pollution, Environmental Management, and Soil Biology and Biochemistry.
Dr. Sadiq's research interests include understanding the fundamental mechanisms governing the fate processes of environmental contaminants (organic and inorganic) and assessing the biogeochemical cycling and ecological impacts of natural organic matter and biomacromolecules. His major research focuses on investigating the development of microbial extracellular polymeric substances mechanisms, effects on microbial cell surfaces, and environmental contaminant's environmental fate, specifically to develop biomacromolecules that could be used to detoxify and recover environmental contaminants.
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