Microbial community structure within a weathered waste-rock pile overlain by a monolayer soil cover

Brayden J. McNeill; Eva Pakostova; Jeff G. Bain; W. Douglas Gould; Richard T. Amos; G. Ward Wilson; Carol J. Ptacek; David W. Blowes

doi:10.1016/j.apgeochem.2020.104531

Microbial community structure within a weathered waste-rock pile overlain by a monolayer soil cover

Brayden J. McNeill, Eva Pakostova, Jeff G. Bain, W. Douglas Gould, Richard T. Amos, G. Ward Wilson, Carol J. Ptacek, David W. Blowes

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

8 Citations (Scopus)

66 Downloads (Pure)

Abstract

A historic waste-rock stockpile (WRS) at the Detour Lake Mine (DLM), covered with a thin layer (<1 m) of local overburden, was studied to determine the potential for microbially-mediated generation of acid rock drainage (ARD). The sulfur content of the waste rock ranged from 0 to 2.2 wt %, with pyrite and pyrrhotite identified as the principal sulfide minerals. Acidity released through sulfide oxidation in the WRS has been neutralized through carbonate mineral dissolution, and has resulted in the generation of neutral mine drainage (pH 6–8). However, the WRS is heterogeneous, and localized water samples collected from discrete zones within the stockpile were more highly oxidized and acidic (i.e., pH ≥ 2.5). Enumerations of acidophilic sulfur- (aSOM) and iron-oxidizing microorganisms (aIOM) were performed, yielding mean abundances of 1.2 × 10 ³ and 9.0 × 10 ⁵ cells g ⁻¹, respectively. The mean abundance of neutrophilic sulfur-oxidizing microorganisms (nSOM) was 5.5 × 10 ⁵ cells g ⁻¹. Fungi and bacteria present in the waste rock were identified using high-throughput amplicon sequencing of 18S and 16S rRNA genes, respectively. Sequencing confirmed the presence of Thiobacillus and Acidithiobacillus species. Bacterial diversity was greatest in samples from the cover material. Unoxidized waste rock samples were characterized by neutrophilic iron- or sulfur-oxidizing genera (i.e., Thiobacillus), whereas samples collected from oxidized and acidic zones in the WRS showed greater abundances of acidophilic taxa (i.e., Acidithiobacillus). None of the fungal genera identified in this study have been shown to oxidize sulfide minerals directly, other than indirectly through creation of a suitable environment for the prokaryotes involved in the processes. Although installation of a simple, non-engineered cover is anticipated to have slowed the generation of ARD, evidence of ongoing sulfide oxidation within the covered WRS was observed. High abundances and activities of sulfur- and iron-oxidizing microorganisms indicate that the soil cover has not prevented the growth of microorganisms that catalyze sulfide-mineral oxidation.

Original language	English
Article number	104531
Number of pages	9
Journal	Applied Geochemistry
Volume	114
Early online date	27 Jan 2020
DOIs	https://doi.org/10.1016/j.apgeochem.2020.104531
Publication status	Published - Mar 2020
Externally published	Yes

Bibliographical note

NOTICE: this is the author’s version of a work that was accepted for publication in Applied Geochemistry,. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Applied Geochemistry, 114 (2020) DOI: 10.1016/j.apgeochem.2020.104531

© 2020, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/

Funder

Funding for this research was provided by Detour Gold Corporation, the Natural Science and Engineering Research Council of Canada (grant CRDPJ 428203-11), and the NSERC TERRE-NET program (grant NETGP 479708-15). T

Keywords

Cell enumerations
High-throughput sequencing
Iron-oxidizing microorganisms
Mine waste
Soil cover
Sulfur-oxidizing microorganisms
Waste rock

ASJC Scopus subject areas

Environmental Chemistry
Pollution
Geochemistry and Petrology

Access to Document

10.1016/j.apgeochem.2020.104531

Post-PrintAccepted author manuscript, 1 MBLicence: CC BY-NC-ND

Cite this

@article{0d50f4e9e8684e0cb4d391fa82224096,

title = "Microbial community structure within a weathered waste-rock pile overlain by a monolayer soil cover",

abstract = "A historic waste-rock stockpile (WRS) at the Detour Lake Mine (DLM), covered with a thin layer (<1 m) of local overburden, was studied to determine the potential for microbially-mediated generation of acid rock drainage (ARD). The sulfur content of the waste rock ranged from 0 to 2.2 wt %, with pyrite and pyrrhotite identified as the principal sulfide minerals. Acidity released through sulfide oxidation in the WRS has been neutralized through carbonate mineral dissolution, and has resulted in the generation of neutral mine drainage (pH 6–8). However, the WRS is heterogeneous, and localized water samples collected from discrete zones within the stockpile were more highly oxidized and acidic (i.e., pH ≥ 2.5). Enumerations of acidophilic sulfur- (aSOM) and iron-oxidizing microorganisms (aIOM) were performed, yielding mean abundances of 1.2 × 10 3 and 9.0 × 10 5 cells g −1, respectively. The mean abundance of neutrophilic sulfur-oxidizing microorganisms (nSOM) was 5.5 × 10 5 cells g −1. Fungi and bacteria present in the waste rock were identified using high-throughput amplicon sequencing of 18S and 16S rRNA genes, respectively. Sequencing confirmed the presence of Thiobacillus and Acidithiobacillus species. Bacterial diversity was greatest in samples from the cover material. Unoxidized waste rock samples were characterized by neutrophilic iron- or sulfur-oxidizing genera (i.e., Thiobacillus), whereas samples collected from oxidized and acidic zones in the WRS showed greater abundances of acidophilic taxa (i.e., Acidithiobacillus). None of the fungal genera identified in this study have been shown to oxidize sulfide minerals directly, other than indirectly through creation of a suitable environment for the prokaryotes involved in the processes. Although installation of a simple, non-engineered cover is anticipated to have slowed the generation of ARD, evidence of ongoing sulfide oxidation within the covered WRS was observed. High abundances and activities of sulfur- and iron-oxidizing microorganisms indicate that the soil cover has not prevented the growth of microorganisms that catalyze sulfide-mineral oxidation. ",

keywords = "Cell enumerations, High-throughput sequencing, Iron-oxidizing microorganisms, Mine waste, Soil cover, Sulfur-oxidizing microorganisms, Waste rock",

author = "McNeill, {Brayden J.} and Eva Pakostova and Bain, {Jeff G.} and Gould, {W. Douglas} and Amos, {Richard T.} and Wilson, {G. Ward} and Ptacek, {Carol J.} and Blowes, {David W.}",

note = "NOTICE: this is the author{\textquoteright}s version of a work that was accepted for publication in Applied Geochemistry,. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Applied Geochemistry, 114 (2020) DOI: 10.1016/j.apgeochem.2020.104531 {\textcopyright} 2020, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ ",

year = "2020",

month = mar,

doi = "10.1016/j.apgeochem.2020.104531",

language = "English",

volume = "114",

journal = "Applied Geochemistry",

issn = "0883-2927",

publisher = "Elsevier",

}

TY - JOUR

T1 - Microbial community structure within a weathered waste-rock pile overlain by a monolayer soil cover

AU - McNeill, Brayden J.

AU - Pakostova, Eva

AU - Bain, Jeff G.

AU - Gould, W. Douglas

AU - Amos, Richard T.

AU - Wilson, G. Ward

AU - Ptacek, Carol J.

AU - Blowes, David W.

N1 - NOTICE: this is the author’s version of a work that was accepted for publication in Applied Geochemistry,. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Applied Geochemistry, 114 (2020) DOI: 10.1016/j.apgeochem.2020.104531 © 2020, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/

PY - 2020/3

Y1 - 2020/3

N2 - A historic waste-rock stockpile (WRS) at the Detour Lake Mine (DLM), covered with a thin layer (<1 m) of local overburden, was studied to determine the potential for microbially-mediated generation of acid rock drainage (ARD). The sulfur content of the waste rock ranged from 0 to 2.2 wt %, with pyrite and pyrrhotite identified as the principal sulfide minerals. Acidity released through sulfide oxidation in the WRS has been neutralized through carbonate mineral dissolution, and has resulted in the generation of neutral mine drainage (pH 6–8). However, the WRS is heterogeneous, and localized water samples collected from discrete zones within the stockpile were more highly oxidized and acidic (i.e., pH ≥ 2.5). Enumerations of acidophilic sulfur- (aSOM) and iron-oxidizing microorganisms (aIOM) were performed, yielding mean abundances of 1.2 × 10 3 and 9.0 × 10 5 cells g −1, respectively. The mean abundance of neutrophilic sulfur-oxidizing microorganisms (nSOM) was 5.5 × 10 5 cells g −1. Fungi and bacteria present in the waste rock were identified using high-throughput amplicon sequencing of 18S and 16S rRNA genes, respectively. Sequencing confirmed the presence of Thiobacillus and Acidithiobacillus species. Bacterial diversity was greatest in samples from the cover material. Unoxidized waste rock samples were characterized by neutrophilic iron- or sulfur-oxidizing genera (i.e., Thiobacillus), whereas samples collected from oxidized and acidic zones in the WRS showed greater abundances of acidophilic taxa (i.e., Acidithiobacillus). None of the fungal genera identified in this study have been shown to oxidize sulfide minerals directly, other than indirectly through creation of a suitable environment for the prokaryotes involved in the processes. Although installation of a simple, non-engineered cover is anticipated to have slowed the generation of ARD, evidence of ongoing sulfide oxidation within the covered WRS was observed. High abundances and activities of sulfur- and iron-oxidizing microorganisms indicate that the soil cover has not prevented the growth of microorganisms that catalyze sulfide-mineral oxidation.

AB - A historic waste-rock stockpile (WRS) at the Detour Lake Mine (DLM), covered with a thin layer (<1 m) of local overburden, was studied to determine the potential for microbially-mediated generation of acid rock drainage (ARD). The sulfur content of the waste rock ranged from 0 to 2.2 wt %, with pyrite and pyrrhotite identified as the principal sulfide minerals. Acidity released through sulfide oxidation in the WRS has been neutralized through carbonate mineral dissolution, and has resulted in the generation of neutral mine drainage (pH 6–8). However, the WRS is heterogeneous, and localized water samples collected from discrete zones within the stockpile were more highly oxidized and acidic (i.e., pH ≥ 2.5). Enumerations of acidophilic sulfur- (aSOM) and iron-oxidizing microorganisms (aIOM) were performed, yielding mean abundances of 1.2 × 10 3 and 9.0 × 10 5 cells g −1, respectively. The mean abundance of neutrophilic sulfur-oxidizing microorganisms (nSOM) was 5.5 × 10 5 cells g −1. Fungi and bacteria present in the waste rock were identified using high-throughput amplicon sequencing of 18S and 16S rRNA genes, respectively. Sequencing confirmed the presence of Thiobacillus and Acidithiobacillus species. Bacterial diversity was greatest in samples from the cover material. Unoxidized waste rock samples were characterized by neutrophilic iron- or sulfur-oxidizing genera (i.e., Thiobacillus), whereas samples collected from oxidized and acidic zones in the WRS showed greater abundances of acidophilic taxa (i.e., Acidithiobacillus). None of the fungal genera identified in this study have been shown to oxidize sulfide minerals directly, other than indirectly through creation of a suitable environment for the prokaryotes involved in the processes. Although installation of a simple, non-engineered cover is anticipated to have slowed the generation of ARD, evidence of ongoing sulfide oxidation within the covered WRS was observed. High abundances and activities of sulfur- and iron-oxidizing microorganisms indicate that the soil cover has not prevented the growth of microorganisms that catalyze sulfide-mineral oxidation.

KW - Cell enumerations

KW - High-throughput sequencing

KW - Iron-oxidizing microorganisms

KW - Mine waste

KW - Soil cover

KW - Sulfur-oxidizing microorganisms

KW - Waste rock

UR - http://www.scopus.com/inward/record.url?scp=85078659127&partnerID=8YFLogxK

U2 - 10.1016/j.apgeochem.2020.104531

DO - 10.1016/j.apgeochem.2020.104531

M3 - Article

SN - 0883-2927

VL - 114

JO - Applied Geochemistry

JF - Applied Geochemistry

M1 - 104531

ER -

Microbial community structure within a weathered waste-rock pile overlain by a monolayer soil cover

Abstract

Bibliographical note

Funder

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this