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The effect of heavy metals on thiocyanate biodegradation by an autotrophic microbial consortium enriched from mine tailings

ABSTRACT: Bioremediation systems represent an environmentally sustainable approach to degrading industrially generated thiocyanate (SCN(−)), with low energy demand and operational costs and high efficiency and substrate specificity. However, heavy metals present in mine tailings effluent may hamper...

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Autores principales: Shafiei, Farhad, Watts, Mathew P., Pajank, Lukas, Moreau, John W.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Springer Berlin Heidelberg 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7778618/
https://www.ncbi.nlm.nih.gov/pubmed/33263791
http://dx.doi.org/10.1007/s00253-020-10983-4
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author Shafiei, Farhad
Watts, Mathew P.
Pajank, Lukas
Moreau, John W.
author_facet Shafiei, Farhad
Watts, Mathew P.
Pajank, Lukas
Moreau, John W.
author_sort Shafiei, Farhad
collection PubMed
description ABSTRACT: Bioremediation systems represent an environmentally sustainable approach to degrading industrially generated thiocyanate (SCN(−)), with low energy demand and operational costs and high efficiency and substrate specificity. However, heavy metals present in mine tailings effluent may hamper process efficiency by poisoning thiocyanate-degrading microbial consortia. Here, we experimentally tested the tolerance of an autotrophic SCN(−)-degrading bacterial consortium enriched from gold mine tailings for Zn, Cu, Ni, Cr, and As. All of the selected metals inhibited SCN(−) biodegradation to different extents, depending on concentration. At pH of 7.8 and 30 °C, complete inhibition of SCN(−) biodegradation by Zn, Cu, Ni, and Cr occurred at 20, 5, 10, and 6 mg L(−1), respectively. Lower concentrations of these metals decreased the rate of SCN(−) biodegradation, with relatively long lag times. Interestingly, the microbial consortium tolerated As even at 500 mg L(−1), although both the rate and extent of SCN(−) biodegradation were affected. Potentially, the observed As tolerance could be explained by the origin of our microbial consortium in tailings derived from As-enriched gold ore (arsenopyrite). This study highlights the importance of considering metal co-contamination in bioreactor design and operation for SCN(−) bioremediation at mine sites. KEY POINTS: • Both the efficiency and rate of SCN(−) biodegradation were inhibited by heavy metals, to different degrees depending on type and concentration of metal. • The autotrophic microbial consortium was capable of tolerating high concentrations of As, potential having adapted to higher As levels derived from the tailings source. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00253-020-10983-4.
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spelling pubmed-77786182021-01-11 The effect of heavy metals on thiocyanate biodegradation by an autotrophic microbial consortium enriched from mine tailings Shafiei, Farhad Watts, Mathew P. Pajank, Lukas Moreau, John W. Appl Microbiol Biotechnol Environmental Biotechnology ABSTRACT: Bioremediation systems represent an environmentally sustainable approach to degrading industrially generated thiocyanate (SCN(−)), with low energy demand and operational costs and high efficiency and substrate specificity. However, heavy metals present in mine tailings effluent may hamper process efficiency by poisoning thiocyanate-degrading microbial consortia. Here, we experimentally tested the tolerance of an autotrophic SCN(−)-degrading bacterial consortium enriched from gold mine tailings for Zn, Cu, Ni, Cr, and As. All of the selected metals inhibited SCN(−) biodegradation to different extents, depending on concentration. At pH of 7.8 and 30 °C, complete inhibition of SCN(−) biodegradation by Zn, Cu, Ni, and Cr occurred at 20, 5, 10, and 6 mg L(−1), respectively. Lower concentrations of these metals decreased the rate of SCN(−) biodegradation, with relatively long lag times. Interestingly, the microbial consortium tolerated As even at 500 mg L(−1), although both the rate and extent of SCN(−) biodegradation were affected. Potentially, the observed As tolerance could be explained by the origin of our microbial consortium in tailings derived from As-enriched gold ore (arsenopyrite). This study highlights the importance of considering metal co-contamination in bioreactor design and operation for SCN(−) bioremediation at mine sites. KEY POINTS: • Both the efficiency and rate of SCN(−) biodegradation were inhibited by heavy metals, to different degrees depending on type and concentration of metal. • The autotrophic microbial consortium was capable of tolerating high concentrations of As, potential having adapted to higher As levels derived from the tailings source. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00253-020-10983-4. Springer Berlin Heidelberg 2020-12-02 2021 /pmc/articles/PMC7778618/ /pubmed/33263791 http://dx.doi.org/10.1007/s00253-020-10983-4 Text en © The Author(s) 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Environmental Biotechnology
Shafiei, Farhad
Watts, Mathew P.
Pajank, Lukas
Moreau, John W.
The effect of heavy metals on thiocyanate biodegradation by an autotrophic microbial consortium enriched from mine tailings
title The effect of heavy metals on thiocyanate biodegradation by an autotrophic microbial consortium enriched from mine tailings
title_full The effect of heavy metals on thiocyanate biodegradation by an autotrophic microbial consortium enriched from mine tailings
title_fullStr The effect of heavy metals on thiocyanate biodegradation by an autotrophic microbial consortium enriched from mine tailings
title_full_unstemmed The effect of heavy metals on thiocyanate biodegradation by an autotrophic microbial consortium enriched from mine tailings
title_short The effect of heavy metals on thiocyanate biodegradation by an autotrophic microbial consortium enriched from mine tailings
title_sort effect of heavy metals on thiocyanate biodegradation by an autotrophic microbial consortium enriched from mine tailings
topic Environmental Biotechnology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7778618/
https://www.ncbi.nlm.nih.gov/pubmed/33263791
http://dx.doi.org/10.1007/s00253-020-10983-4
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