Abstract

Molecular microbiology tools (i.e., 16S rDNA gene sequencing) were employed to elucidate changes in the microbial community structure according to the total electron acceptor loading (controlled by influent flow rate and/or medium composition) in a H2-based membrane biofilm reactor evaluated for removal of hexavalent uranium. Once nitrate, sulfate, and dissolved oxygen were replaced by U(VI) and bicarbonate and the total acceptor loading was lowered, slow-growing bacteria capable of reducing U(VI) to U(IV) dominated in the biofilm community: Replacing denitrifying bacteria Rhodocyclales and Burkholderiales were spore-producing Clostridiales and Natranaerobiales. Though potentially competing for electrons with U(VI) reducers, homo-acetogens helped attain steady U(VI) reduction, while methanogenesis inhibited U(VI) reduction. U(VI) reduction was reinstated through suppression of methanogenesis by addition of bromoethanesulfonate or by competition from SRB when sulfate was re-introduced. Predictive metagenome analysis further points out community changes in response to alterations in the electron-acceptor loading: Sporulation and homo-acetogenesis were critical factors for strengthening stable microbial U(VI) reduction. This study documents that sporulation was important to long-term U(VI) reduction, whether or not microorganisms that carry out U(VI) reduction mediated by cytochrome c3, such as SRB and ferric-iron-reducers, were inhibited.

Original languageEnglish (US)
Pages (from-to)341-349
Number of pages9
JournalWater Research
Volume125
DOIs
StatePublished - Nov 15 2017

Fingerprint

Biofilms
Uranium
biofilm
microbial community
uranium
community structure
membrane
Membranes
electron
Electrons
Chemical analysis
sporulation
methanogenesis
Bacteria
sulfate
Microbiology
bacterium
microbiology
Dissolved oxygen
bicarbonate

Keywords

  • Acceptor loadings
  • Homoacetogens
  • Methanogens
  • Spore-forming microorganisms
  • Sulfate reducers
  • Uranium reduction

ASJC Scopus subject areas

  • Ecological Modeling
  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution

Cite this

Total electron acceptor loading and composition affect hexavalent uranium reduction and microbial community structure in a membrane biofilm reactor. / Ontiveros-Valencia, Aura; Zhou, Chen; Ilhan, Zehra Esra; de Saint Cyr, Louis Cornette; Krajmalnik-Brown, Rosa; Rittmann, Bruce.

In: Water Research, Vol. 125, 15.11.2017, p. 341-349.

Research output: Contribution to journalArticle

@article{4ebe0477e3a045fa8fc35d507c7b3cd8,
title = "Total electron acceptor loading and composition affect hexavalent uranium reduction and microbial community structure in a membrane biofilm reactor",
abstract = "Molecular microbiology tools (i.e., 16S rDNA gene sequencing) were employed to elucidate changes in the microbial community structure according to the total electron acceptor loading (controlled by influent flow rate and/or medium composition) in a H2-based membrane biofilm reactor evaluated for removal of hexavalent uranium. Once nitrate, sulfate, and dissolved oxygen were replaced by U(VI) and bicarbonate and the total acceptor loading was lowered, slow-growing bacteria capable of reducing U(VI) to U(IV) dominated in the biofilm community: Replacing denitrifying bacteria Rhodocyclales and Burkholderiales were spore-producing Clostridiales and Natranaerobiales. Though potentially competing for electrons with U(VI) reducers, homo-acetogens helped attain steady U(VI) reduction, while methanogenesis inhibited U(VI) reduction. U(VI) reduction was reinstated through suppression of methanogenesis by addition of bromoethanesulfonate or by competition from SRB when sulfate was re-introduced. Predictive metagenome analysis further points out community changes in response to alterations in the electron-acceptor loading: Sporulation and homo-acetogenesis were critical factors for strengthening stable microbial U(VI) reduction. This study documents that sporulation was important to long-term U(VI) reduction, whether or not microorganisms that carry out U(VI) reduction mediated by cytochrome c3, such as SRB and ferric-iron-reducers, were inhibited.",
keywords = "Acceptor loadings, Homoacetogens, Methanogens, Spore-forming microorganisms, Sulfate reducers, Uranium reduction",
author = "Aura Ontiveros-Valencia and Chen Zhou and Ilhan, {Zehra Esra} and {de Saint Cyr}, {Louis Cornette} and Rosa Krajmalnik-Brown and Bruce Rittmann",
year = "2017",
month = "11",
day = "15",
doi = "10.1016/j.watres.2017.08.060",
language = "English (US)",
volume = "125",
pages = "341--349",
journal = "Water Research",
issn = "0043-1354",
publisher = "Elsevier Limited",

}

TY - JOUR

T1 - Total electron acceptor loading and composition affect hexavalent uranium reduction and microbial community structure in a membrane biofilm reactor

AU - Ontiveros-Valencia, Aura

AU - Zhou, Chen

AU - Ilhan, Zehra Esra

AU - de Saint Cyr, Louis Cornette

AU - Krajmalnik-Brown, Rosa

AU - Rittmann, Bruce

PY - 2017/11/15

Y1 - 2017/11/15

N2 - Molecular microbiology tools (i.e., 16S rDNA gene sequencing) were employed to elucidate changes in the microbial community structure according to the total electron acceptor loading (controlled by influent flow rate and/or medium composition) in a H2-based membrane biofilm reactor evaluated for removal of hexavalent uranium. Once nitrate, sulfate, and dissolved oxygen were replaced by U(VI) and bicarbonate and the total acceptor loading was lowered, slow-growing bacteria capable of reducing U(VI) to U(IV) dominated in the biofilm community: Replacing denitrifying bacteria Rhodocyclales and Burkholderiales were spore-producing Clostridiales and Natranaerobiales. Though potentially competing for electrons with U(VI) reducers, homo-acetogens helped attain steady U(VI) reduction, while methanogenesis inhibited U(VI) reduction. U(VI) reduction was reinstated through suppression of methanogenesis by addition of bromoethanesulfonate or by competition from SRB when sulfate was re-introduced. Predictive metagenome analysis further points out community changes in response to alterations in the electron-acceptor loading: Sporulation and homo-acetogenesis were critical factors for strengthening stable microbial U(VI) reduction. This study documents that sporulation was important to long-term U(VI) reduction, whether or not microorganisms that carry out U(VI) reduction mediated by cytochrome c3, such as SRB and ferric-iron-reducers, were inhibited.

AB - Molecular microbiology tools (i.e., 16S rDNA gene sequencing) were employed to elucidate changes in the microbial community structure according to the total electron acceptor loading (controlled by influent flow rate and/or medium composition) in a H2-based membrane biofilm reactor evaluated for removal of hexavalent uranium. Once nitrate, sulfate, and dissolved oxygen were replaced by U(VI) and bicarbonate and the total acceptor loading was lowered, slow-growing bacteria capable of reducing U(VI) to U(IV) dominated in the biofilm community: Replacing denitrifying bacteria Rhodocyclales and Burkholderiales were spore-producing Clostridiales and Natranaerobiales. Though potentially competing for electrons with U(VI) reducers, homo-acetogens helped attain steady U(VI) reduction, while methanogenesis inhibited U(VI) reduction. U(VI) reduction was reinstated through suppression of methanogenesis by addition of bromoethanesulfonate or by competition from SRB when sulfate was re-introduced. Predictive metagenome analysis further points out community changes in response to alterations in the electron-acceptor loading: Sporulation and homo-acetogenesis were critical factors for strengthening stable microbial U(VI) reduction. This study documents that sporulation was important to long-term U(VI) reduction, whether or not microorganisms that carry out U(VI) reduction mediated by cytochrome c3, such as SRB and ferric-iron-reducers, were inhibited.

KW - Acceptor loadings

KW - Homoacetogens

KW - Methanogens

KW - Spore-forming microorganisms

KW - Sulfate reducers

KW - Uranium reduction

UR - http://www.scopus.com/inward/record.url?scp=85028704381&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85028704381&partnerID=8YFLogxK

U2 - 10.1016/j.watres.2017.08.060

DO - 10.1016/j.watres.2017.08.060

M3 - Article

C2 - 28881210

AN - SCOPUS:85028704381

VL - 125

SP - 341

EP - 349

JO - Water Research

JF - Water Research

SN - 0043-1354

ER -