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Microbial mercury methylation and demethylation
Descriptive
TitleInfo
Title
Microbial mercury methylation and demethylation
SubTitle
biogeochemical mechanisms and metagenomic perspectives in freshwater ecosystems
Name
(type = personal)
NamePart
(type = family)
Yu
NamePart
(type = given)
Riqing
DisplayForm
Riqing Yu
Role
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(authority = RULIB)
author
Name
(type = personal)
NamePart
(type = family)
Barkay
NamePart
(type = given)
Tamar
DisplayForm
Tamar Barkay
Affiliation
Advisory Committee
Role
RoleTerm
(authority = RULIB)
chair
Name
(type = personal)
NamePart
(type = family)
Reinfelder
NamePart
(type = given)
John
DisplayForm
John Reinfelder
Affiliation
Advisory Committee
Role
RoleTerm
(authority = RULIB)
internal member
Name
(type = personal)
NamePart
(type = family)
Häggblom
NamePart
(type = given)
Max M.
DisplayForm
Max M. Häggblom
Affiliation
Advisory Committee
Role
RoleTerm
(authority = RULIB)
internal member
Name
(type = personal)
NamePart
(type = family)
Hines
NamePart
(type = given)
Mark E.
DisplayForm
Mark E. Hines
Affiliation
Advisory Committee
Role
RoleTerm
(authority = RULIB)
outside member
Name
(type = corporate)
NamePart
Rutgers University
Role
RoleTerm
(authority = RULIB)
degree grantor
Name
(type = corporate)
NamePart
Graduate School - New Brunswick
Role
RoleTerm
(authority = RULIB)
school
TypeOfResource
Text
Genre
(authority = marcgt)
theses
OriginInfo
DateCreated
(qualifier = exact)
2011
DateOther
(qualifier = exact);
(type = degree)
2011-05
Place
PlaceTerm
(type = code)
xx
Language
LanguageTerm
(authority = ISO639-2b);
(type = code)
eng
Abstract
(type = abstract)
Elevated concentration of methylmercury (MeHg) in fish is a worldwide concern due to its detrimental effects on human health. Although Hg methylation is a key issue regarding MeHg contamination, neither abiotic nor microbial methylation mechanisms are well understood. The overall objective of this study was to link the potential for microbial methylation and demethylation to the molecular characterization of microbial communities in two typical freshwater ecosystems and to gain in-depth understanding of Hg methylation mechanisms by syntrophy. Sunday Lake is a remote and “pristine” forest lake exposed to Hg mostly through atmospheric deposition in the Adirondack Mountains, New York. This study demonstrated that floating Sphagnum moss mats near the lake water front were hot spots for MeHg accumulation and microbial methylation, and sub-habitats where sulfate reducing bacteria (SRB) community was highly developed. SRB were identified as a major group of Hg methylators, as sulfate addition to the mat samples doubled the potential Hg methylation rates while molybdate significantly inhibited them. The dominant distribution of Syntrophobacter spp. in the Sphagnum mats led to the investigation of syntrophy in Hg methylation. By incubating mono- or co-cultures of Syntrophobacter spp., with Desulfovibrio spp., this study was the first to demonstrate that a Syntrophobacter-Desulfovibrio coculture significantly increased growth of both syntrophic partners and stimulated MeHg synthesis compared to activities of Desulfovibro spp. monocultures. Syntrophy could stimulate MeHg synthesis by two pathways: Desulfovibrio growing with methanogens in sulfate-free environments, and Desulfovibrio growing with Syntrophobacter in sulfate-limited environments where sources of energy and carbon are limited. In the South River, an industrially Hg-contaminated site in Virginia, high Hg methylation rates and low demethylation activities were observed in nine sites downstream from the contaminating source, partially explaining why fish in this river have high MeHg levels. 16S rRNA sequencing from sediment cDNA showed that at least three groups of SRB and one group of Geobacter-like iron reducing bacteria (IRB) that were closely affiliated to known Hg methylators, were active in the sediments. Further metabolic inhibition and stimulation experiments confirmed that both SRB and IRB were involved in the microbial methylation in South River sediments.
Subject
(authority = RUETD)
Topic
Environmental Sciences
RelatedItem
(type = host)
TitleInfo
Title
Rutgers University Electronic Theses and Dissertations
Identifier
(type = RULIB)
ETD
Identifier
ETD_3298
PhysicalDescription
Form
(authority = gmd)
electronic resource
InternetMediaType
application/pdf
InternetMediaType
text/xml
Extent
xiii, 206 p. : ill.
Note
(type = degree)
Ph.D.
Note
(type = bibliography)
Includes bibliographical references
Note
(type = statement of responsibility)
by Riqing Yu
Subject
(authority = ETD-LCSH)
Topic
Fishes—Mercury content
Subject
(authority = ETD-LCSH)
Topic
Mercury—Toxicology
Subject
(authority = ETD-LCSH)
Topic
Freshwater habitats
Identifier
(type = hdl)
http://hdl.rutgers.edu/1782.1/rucore10001600001.ETD.000061548
RelatedItem
(type = host)
TitleInfo
Title
Graduate School - New Brunswick Electronic Theses and Dissertations
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rucore19991600001
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NjNbRU
Identifier
(type = doi)
doi:10.7282/T3RV0N0D
Genre
(authority = ExL-Esploro)
ETD doctoral
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Rights
RightsDeclaration
(ID = rulibRdec0006)
The author owns the copyright to this work.
RightsHolder
(type = personal)
Name
FamilyName
Yu
GivenName
Riqing
Role
Copyright Holder
RightsEvent
Type
Permission or license
DateTime
(encoding = w3cdtf);
(point = start);
(qualifier = exact)
2011-04-14 14:45:09
AssociatedEntity
Name
Riqing Yu
Role
Copyright holder
Affiliation
Rutgers University. Graduate School - New Brunswick
AssociatedObject
Type
License
Name
Author Agreement License
Detail
I hereby grant to the Rutgers University Libraries and to my school the non-exclusive right to archive, reproduce and distribute my thesis or dissertation, in whole or in part, and/or my abstract, in whole or in part, in and from an electronic format, subject to the release date subsequently stipulated in this submittal form and approved by my school. I represent and stipulate that the thesis or dissertation and its abstract are my original work, that they do not infringe or violate any rights of others, and that I make these grants as the sole owner of the rights to my thesis or dissertation and its abstract. I represent that I have obtained written permissions, when necessary, from the owner(s) of each third party copyrighted matter to be included in my thesis or dissertation and will supply copies of such upon request by my school. I acknowledge that RU ETD and my school will not distribute my thesis or dissertation or its abstract if, in their reasonable judgment, they believe all such rights have not been secured. I acknowledge that I retain ownership rights to the copyright of my work. I also retain the right to use all or part of this thesis or dissertation in future works, such as articles or books.
RightsEvent
DateTime
(encoding = w3cdtf);
(point = start);
(qualifier = exact)
2011-05-31
DateTime
(encoding = w3cdtf);
(point = end);
(qualifier = exact)
2014-05-31
Type
Embargo
Detail
Access to this PDF has been restricted at the author's request. It will be publicly available after May 31, 2014.
Copyright
Status
Copyright protected
Availability
Status
Open
Reason
Permission or license
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