Jeffra Schaefer

About

Professor Jeffra Schaefer's research centers on the microbial communities and their activities in peatlands, particularly focusing on boreal and arctic wetlands that play a significant role in global soil carbon sequestration. Her work investigates how microbial populations in these environments break down organic matter into methane and carbon dioxide, contributing to greenhouse gas emissions. She studies the effects of climate change, such as warming trends and permafrost melting, on the transition of wetlands from nutrient-poor bogs to richer fens, and how these changes influence microbial metabolic pathways and community dynamics. This research is crucial for predicting future environmental trends related to carbon cycling in high latitude ecosystems. Another major focus of Professor Schaefer's research is the microbial production of methylmercury in northern wetlands. Methylmercury is a potent neurotoxin that bioaccumulates in food webs, posing health risks to humans and wildlife. Her work explores the biogeochemical and microbial controls that regulate mercury methylation in wetland environments, which are known hotspots for this process due to their anoxic conditions and organic matter abundance. Collaborating with researchers from institutions such as Rutgers University, University of Massachusetts Amherst, and the US Geological Survey, she examines the links between wetland type, microbial populations, and methylmercury accumulation to better understand and predict…

Research topics

• Biology
• Ecology
• Environmental chemistry
• Chemistry
• Organic chemistry
• Inorganic chemistry

Selected publications

• Terrestrial discharges mediate trophic shifts and enhance methylmercury accumulation in estuarine biota

  Science Advances · 2017-01-06 · 123 citations

  articleOpen access

  The input of mercury (Hg) to ecosystems is estimated to have increased two- to fivefold during the industrial era, and Hg accumulates in aquatic biota as neurotoxic methylmercury (MeHg). Escalating anthropogenic land use and climate change are expected to alter the input rates of terrestrial natural organic matter (NOM) and nutrients to aquatic ecosystems. For example, climate change has been projected to induce 10 to 50% runoff increases for large coastal regions globally. A major knowledge gap…

  PublisherOA PDFDOI

• <i>Geobacteraceae</i> are important members of mercury-methylating microbial communities of sediments impacted by waste water releases

  The ISME Journal · 2018-01-09 · 111 citations

  articleOpen access

  Microbial mercury (Hg) methylation in sediments can result in bioaccumulation of the neurotoxin methylmercury (MMHg) in aquatic food webs. Recently, the discovery of the gene hgcA, required for Hg methylation, revealed that the diversity of Hg methylators is much broader than previously thought. However, little is known about the identity of Hg-methylating microbial organisms and the environmental factors controlling their activity and distribution in lakes. Here, we combined high-throughput seq…

  PublisherOA PDFDOI

• Fractionation of Mercury Stable Isotopes during Microbial Methylmercury Production by Iron- and Sulfate-Reducing Bacteria

  Environmental Science & Technology · 2016-07-08 · 111 citations

  article

  The biological production of monomethylmercury (MeHg) in soils and sediments is an important factor controlling mercury (Hg) accumulation in aquatic and terrestrial food webs. In this study we examined the fractionation of Hg stable isotopes during Hg methylation in nongrowing cultures of the anaerobic bacteria Geobacter sulfurreducens PCA and Desulfovibrio desulfuricans ND132. Both organisms showed mass-dependent, but no mass-independent fractionation of Hg stable isotopes during Hg methylation…

  PublisherDOI

• The role of oxygen in stimulating methane production in wetlands

  Global Change Biology · 2021 · 77 citations

  emissions; and guiding wetland C management strategies.

  PublisherOA PDFDOI

• Methanogens and Iron-Reducing Bacteria: the Overlooked Members of Mercury-Methylating Microbial Communities in Boreal Lakes

  Applied and Environmental Microbiology · 2018-09-21 · 71 citations

  articleOpen access

  Despite the global awareness that mercury, and methylmercury in particular, is a neurotoxin to which millions of people continue to be exposed, there are sizable gaps in the understanding of the processes and organisms involved in methylmercury formation in aquatic ecosystems. In the present study, we shed light on the diversity of the microorganisms responsible for methylmercury formation in boreal lake sediments. All the microorganisms identified are associated with the processing of organic m…

  PublisherOA PDFDOI

Frequent coauthors

• Tamar Barkay

  Rutgers, The State University of New Jersey

  15 shared

• Ulf Skyllberg

  Swedish University of Agricultural Sciences

  11 shared

• Erik Björn

  Umeå University

  11 shared

• Andrea G. Bravo

  Institut de Ciències del Mar

  11 shared

• François M. M. Morel

  Princeton University

  9 shared

• John R. Reinfelder

  Rutgers, The State University of New Jersey

  8 shared

• Moritz Buck

  Swedish University of Agricultural Sciences

  6 shared

• Stefan Bertilsson

  Swedish University of Agricultural Sciences

  6 shared

Education

• PhD

  Rutgers University

  2005

• BA

  University of California Berkeley

  1997

Similar researchers at Rutgers University

• Anthony Broccolih-47
• Enrique Curchitserh-44