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Stay in touch with all the latest news and research findings from BETCy. News items will be periodically distributed in electronic format. Please contact the Operations Manager to sign up for a subscription or view archived issues.


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Biological methane production from bactrial iron-only nitrogenase
BETCy News Release
April 2018

Methane production Methane (CH4) is a potent greenhouse gas, roughly 30 times more potent than carbon dioxide (CO2). CH4 is released from fossil fuels and is also produced by microbial activity, with at least one billion tons of CH4 being formed and consumed by microorganisms in a single year. Complex methanogenesis pathways used by archaea have long been believed to be the exclusive route for CH4 production in nature.

A recent paper by BETCy researchers describing a new pathway for methane production using bacterial Fe-only nitrogenase was published in the Jan. 15, 2018 issue of the journal Nature Microbiology. The work is also highlighted in a News and Views article in the same issue of the journal.

This paper reveals that Fe-only nitrogenase converts nitrogen gas to ammonia and CO2 into CH4 at the same time. This discovery is significant because it represents a potential new source of methane, a major part of the carbon cycle and a major greenhouse gas, in the environment. Fe-only nitrogenase represents one of the three different types of nitrogenases, which are each differentiated by the metal composition in the active site cofactor: MoFe, VFe, or FeFe. Though the flux of electrons for CO2 reduction to CH4 by Fe-only nitrogenase is relatively small, the amount of CH4 generated is enough to allow a methane-utilizing bacterium to grow in co-culture with a bacterium named Rhodopseudomonas palustris that is expressing Fe-only nitrogenase.

"The Fe-only nitrogenase has been a neglected enzyme, which is active in microbes more often and in more conditions than we had previously thought," said Yanning Zheng, lead author of the study, who is a senior fellow in BETCy's Harwood Laboratory at the University of Washington.

BETCy scientists with different backgrounds worked together on this project to examine the distribution of Fe-only nitrogenases in microbes and their functions both in vivo and in vitro. The interdisciplinary project was made possible by integrating microbiologists at BETCy labs at University of Washington, geobiologists at Montana State University, and enzymologists at Utah State University. This discovery gives us a new understanding of biological CH4 production in nature, the global carbon cycle, and the interactions in microbial communities.

 

John Peters earns dual fellowships with AAM and AAAS
BETCy News Release
April 2018

John PetersBETCy director John Peters has been named a Fellow in the American Academy of Microbiology. This is Peters' second such honor in the last three months: last fall he was named a Fellow in the American Association for the Advancement of Science for his contributions in chemistry.

Peters also directs the Institute of Biological Chemistry at Washington State University. The American Academy of Microbiology represents the American Society for Microbiology, the world's oldest and largest life science organization. The mission of the Academy is to recognize scientists for outstanding contributions to microbiology and provide microbiological expertise in the service of science and the public.

"I hope the work I've done with my colleagues brings a better understanding of how living organisms use energy, leading to reduced fertilizer use or increased efficiency in our use of energy," Peters said. "This research we've done lays the groundwork to help grow crops or make energy production and utilization more efficient."

Peters said he also is proud of the recognition in two completely different fields: chemistry and microbiology. "It says a lot about the scope of our program and what we do to advance science," he said.

Peters' election as an American Association for the Advancement of Science (AAAS) Fellow is a distinction bestowed upon AAAS members by their peers, in recognition of scientifically or socially distinguished efforts to advance science and its applications.

"We've done some groundbreaking work that's laid the foundation for others to follow," Peters said. "That's the most rewarding part of my research, that a lot of significant science has been born out of the work my colleagues and I have done."

That foundation includes discovering how to make energy much more efficiently. For example, it has the potential, though it's still very early, to extract more energy from biomass when making biofuels, Peters said.

"It's an honor to be nominated by people that I respect so much," Peters said. "I'm greatly appreciative that they took the time and effort to nominate me and feel my work is valuable to our field."

 

Fe-nitrogenase active site FeFe-cofactor detailed in Biochemistry
BETCy News Release
February 2018

FeFe-cofactorIn a second paper describing nitrogenase, BETCy research has illuminated key mechanistic details of the N2 reduction mechanism for the Fe-nitrogenase active site FeFe-cofactor. The work was published in the Feb. 6, 2018 issue of the journal Biochemistry.

There are three forms of nitrogenase: Mo-nitrogenase, V-nitrogenase, and Fe-nitrogenase. While structurally similar, the forms differ in the metal content of their active site cofactors and are reported to reduce N2 at different rates with varying efficiency.

Fe-nitrogenase is the rarest and least understood of the forms, as well as being the poorest at N2 reduction. In the conventional Mo-nitrogenase, binding of N2 to the cofactor is known to follow a reductive elimination/oxidative addition (re/oa) mechanism. In this re/oa, two bridging Fe-H-Fe hydrides are reductively eliminated as N2 undergoes oxidative addition to the cofactor. A key feature of the mechanism is that it is reversible with hydrogen gas (H2), such that H2 effectively inhibits N2 reduction. Due to its differences from the Mo-nitrogenase, it was unclear if the Fe-nitrogenase would follow this same mechanism.

In this publication, it is demonstrated that Fe-nitrogenase also follows the re/oa mechanism for binding N2 to its cofactor. It is also shown that the enzyme has a relatively low affinity for N2 as a substrate, providing insight into its poor reduction activity.

Lead author Derek Harris, a graduate student in the Seefeldt Group at Utah State University, purified the component proteins of the Fe-nitrogenase from Azotobacter vinelandii. The system was biochemically characterized and tested for the ability of hydrogen gas (H2) to inhibit N2 reduction. H2 did inhibit N2reduction and when presented with deuterium gas (D2) in place of H2, HD was detected by mass-spectrometry, confirming a reversible re/oa mechanism. N2 is reductively eliminated from the cofactor and D2 undergoes oxidative addition as two Fe-D-Fe deuterides. As the cofactor relaxes, the deuterides are released and coordinate with a proton to form HD.

In examining the partial pressure dependence of N2 on NH3 formation, Fe-nitrogenase displayed the same previously reported inefficiency (producing excess H2 per N2 reduced). However, it was also revealed that Fe-nitrogenase has a five-fold lower affinity for N2 than the Mo-nitrogenase. Because of this, it is difficult to put Fe-nitrogenase under a saturating concentration of N2. Extrapolating to what would be a saturating concentration Fe-nitrogenase should achieve the same efficiency as Mo-nitrogenase. This lowered affinity and efficiency is likely a result of the effect differing metals in the cofactor has on its electronics.

Overall, this work provides evidence for a unifying mechanism for N2 binding amongst the forms of nitrogenase. It also provides insights into how nature has evolved redundant systems to ensure that this crucial reaction is carried out, albeit with compromises.

 

BETCy scientists publish on the thermodynamics and kinetics of electron bifurcation
BETCy News Release
September 2017

Electron BifucationIn collaboration between BETCy experimentalists at Washington State University and National Renewable Energy Laboratory, theoretical chemists Peng Zhang and Jonathon Yuly in BETCy's Beratan research group at Duke University published in the September 2017 issue of Accounts of Chemical Research.

This paper accomplished two significant goals. First, it is one of the first publications to place biological electron bifurcation on firm thermodynamic footing. Second, it rationalizes the correct electron transfer sequence for the bifurcating steps of the catalytic cycle in the Nfn enzyme (NADH-dependent reduced ferredoxin: NADP+ oxidoreductase I).

In their analysis of the thermodynamics of the reaction, the authors considered the reduction potentials of the cofactors and the distances between cofactors, assuming that the initial steps along each branch obey the kinetics of nonadiabatic electron-transfer theory. The Nfn reaction mechanism begins with sending the first electron from the bifurcating flavin site up the high potential branch towards NAD+.

The first electron transfer switches on a second thermodynamically spontaneous electron transfer reaction from the flavin along a second pathway that moves the second electron in the opposite direction and at a lower potential. The second electron is sent down the low potential branch towards ferredoxin; thus the second electron to leave the flavin is much more reducing than the first: the potentials are said to be "crossed."

Using thermodynamic considerations, the paper shows that electron bifurcation can occur without crossed potentials. However, crossed potentials may yield distinct advantages for biological electron bifurcation. For instance, when a bifurcating species is in the crossed potential landscape, its low potential redox state can be extremely short lived (~10 ps in Nfn). This allows the system to use that highly reducing state without having to protect it from energy dissipating electron acceptors.

Graduate students Diep Nguyen at UGA and Jonathon Yuly at Duke presented the results of this study as part of the Team Science Competition held at the 2017 EFRC PIs Meeting in Washington, DC.

 

BETCy team establishes role of electron bifurcation in nitrogen fixation
BETCy News Release
September 2017

Electron BifucationThe nitrogenase enzyme catalyzes the reduction of dinitrogen (N2) to a bioavailable form (NH3) in an energy intensive reaction that requires both ATP and a strong reductant containing high-energy electrons. The pathways that generate the high-energy electrons, however, have remained elusive for many nitrogen-fixing bacteria. In a recent publication, BETCy scientists showed that some nitrogen-fixing bacteria generate strong reductants using the so-called FixABCX enzyme complex.

The Fix complex bifurcates electrons from NADH, sending half the electrons down a high-energy pathway while sending the remaining electrons down a lower energy path. Lead author Rhesa Ledbetter, a graduate student in the Seefeldt research group at Utah State University, started by purifying the electron-bifurcating FixABCX complex from the nitrogen-fixing bacterium, Azotobacter vinelandi.

The purified complex was biochemically characterized, and demonstrated to generate reductant for nitrogen fixation using a mechanism that involves electron bifurcation. Biochemical and biophysical data supported a pathway in which two electrons are donated to FixABCX from NADH and then split to proceed down two different pathways-one electron going down the exergonic branch to coenzyme Q and the other traveling down the endergonic branch to a small electron carrier protein, flavodoxin. The high-energy electrons in flavodoxin can then be used to as the reductant for nitrogenase. The BETCy team also confirmed that the FixABCX complex does, in fact, donate electrons to nitrogenase in A. vinelandii whole cells, confirming a physiological role.

Overall, this work establishes a new pathway for the generation of reductant for one of the most difficult biological reactions and provides insight into roles of electron bifurcating complexes in living systems. The work on the FixABCX electron bifurcating complex was published in the Aug. 15, 2017 issue of the journal Biochemistry and was a collaboration among Utah State University, Montana State University, National Renewable Energy Laboratory, Idaho State University, University of Minnesota, University of Kentucky, and Washington State University.

 

BETCy EFRC scientists discover mechanistic details of electron bifurcation
BETCy News Release
April 2017

Electron BifucationIn a new publication, BETCy scientists have uncovered some of the hidden mechanistic details of electron bifurcation. Bifurcating enzymes are able to take energy from one source and split it into two pathways in order to produce two different high-energy compounds, one of which is difficult to make. This process allows certain enzymes to harness energy from chemical reactions that previously would have been sloughed off as unusable heat. Understanding this process - which maximizes the efficiency of reactions at the molecular level - could affect everything from synthetic biology to fuel and chemical production.

The publication, “Mechanistic insights into energy conservation by flavin-based electron bifurcation” was published online 10 April 2017 in the journal Nature Chemical Biology.

DOWNLOAD FULL NEWS RELEASE »


 

Dr. David N. Beratan selected to receive the Florida Award from the American Chemical Society
BETCy News Release
April 2017

David N. BeratanDr. David N. Beratan of Duke University, a researcher with the Biological Electron Transfer and Catalysis (BETCy) Energy Frontier Research Center, has been selected to receive the Florida Award from the American Chemical Society. Award details are posted on the ACS-Florida Section website.

The award is granted annually to a resident of the southeastern United States who has made outstanding contributions to teaching, research, publications or service in advancing the profession of chemistry. Dr. Beratran was recognized for his contributions to theoretical biophysics and biophysical chemistry, along with major impacts in teaching and service. The award will be presented during the Florida Annual Meeting and Exposition in May 2017.

Dr. Beratan is Duke's R.J. Reynolds Professor of Chemistry and is also affiliated with the Departments of Biochemistry and Physics, as well as Duke's programs in Computational Biology and Bioinformatics, Structural Biology and Biophysics, Nanosciences, and Phononics. Dr. Beratan's laboratory joined the BETCy EFRC in Fall 2016 and strengthens BETCy's foundation by applying theoretical approaches to understanding the mechanisms underlying electron bifurcation. BETCy is one of 36 Energy Frontier Research Centers established by the U.S. Department of Energy's Office of Basic Energy Sciences. All are focused on laying the scientific groundwork to meet the global need for abundant, clean, and economical energy. BETCy is housed at Montana State University in Bozeman, Montana.

VISIT THE ACS FLORIDA SECTION WEBSITE »


 

Dr. Anne-Frances Miller recently chosen as Chair-Elect of the American Chemical Society-Division of Biological Chemistry
BETCy News Release
April 2017

Anne-Frances Miller Dr. Anne-Frances Miller of University of Kentucky and a researcher with the Biological Electron Transfer and Catalysis (BETCy) Energy Frontier Research Center, was recently chosen as Chair-Elect of the American Chemical Society-Division of Biological Chemistry (ACS-DBC). The DBC is a 7000-member technical division of the American Chemical Society that administers awards, supports regional meetings and encourages participation of biochemists in the ACS. Miller’s election was announced in the Winter/Spring issue of the ACS-DBC newsletter.

During her ACS-DBC tenure, Dr. Miller hopes to leverage her experience at universities and her ties with industry and business to increase biochemists' access to diverse career trajectories and to expand the participation and relevance of biological chemistry in decision-making by leadership at the state and national levels.

Miller is Professor of Chemistry and Director of the University of Kentucky NMR spectroscopy facility. Off-campus, Miller is involved in educating the next generation of scientists as coordinator of outreach for the UK Department of Chemistry.

In a recent address to members of the Southeast Enzyme Conference, Miller stated, "Our community includes tremendous wisdom and great energy and ambition. We have to be careful about how we allocate our time, so I would like to begin my tenure in this office by hearing from you, my fellow biochemists, about where you think our time and money could have the largest most enduring impact for our community, our country and our planet."

DOWNLOAD ACS-DBC NEWSLETTER »


 

Scientists from BETCy EFRC describe light-driven conversion of greenhouse gas to fuel
BETCy News Release
August 2016

Green light. Researchers funded by the Department of Energy Office of Science’s Energy Frontier Research Center program have used a phototropic bacterium as a biocatalyst to generate methane from carbon dioxide in one enzymatic step. The team says the break-through puts them one step closer to cleanly converting harmful carbon dioxide emissions from fossil fuel combustion into usable fuels. The lead scientists, who are located at Utah State University and the University of Washington, are part of the multi-institutional Center for Biological Electron Transfer and Catalysis (BETCy) EFRC, a seven-institution collaboration that is housed at Montana State University.

DOWNLOAD NEWS RELEASE »

 

RELATED ARTICLES

Light-driven carbon dioxide reduction to methane by nitrogenase in a photosynthetic bacterium
Proceedings of the National Academy of Sciences of the United States of America (PNAS)
August 2016

Engineered bacterium turns carbon dioxide into methane fuel
Scientific American
August 2016

Green light: Biochemists describe light-driven conversion of greenhouse gas to fuel
Phys.org
August 2016

 

Tackling complex problems in energy science: The importance of interdisciplinary teams
Energy Frontier Research Centers (EFRC) Newsletter
Summer 2016

ICNF-19 Dan Colman, post-doctoral student at Montana State University Bozeman, wrote the feature article for the Summer 2016 EFRC newsletter. In the article, he explains the origin and goals of EFRCs, and how incorporating diverse, interdisciplinary teams is key to solving energy-related scientific problems across diverse energy technology areas.

Read the entire article http://www.energyfrontier.us/newsletter/201607/tackling-complex-problems-energy-science-importance-interdisciplinary-teams.

 

BETCy scientists help organize 19th International Congress on Nitrogen Fixation
BETCy Newsletter
February, 2016

ICNF-19 BETCy Director John Peters and BETCy PIs Lance Seefeldt and Caroline Harwood took part in the 19th International Congress on Nitrogen Fixation (ICNF), Oct. 4-9 at the historic Asilomar Conference Grounds in Pacific Grove, Calif. BETCy Program Manager Robert Stack also attended.

The ICNF is a forum for scientists from around the world to present results related to nitrogen fixation. The congress has been held periodically since the first meeting was organized in 1974 at Pullman, Washington.

A broad spectrum of topics was discussed at the ICNF conference, including sessions ranging in scope from the macro to the micro, including Global Aspects of Nitrogen Fixation, Evolution and Ecology; Synthetic Biology; Biochemistry; and Inorganic Chemistry & Nitrogen Fixation. The 19th ICNF included daily plenary session talks, parallel session talks, and poster sessions.

GroupPeters discussed recent results in the presentation entitled, “Evolution of Mo N2ase during Transition from Anaerobic to Aerobic Metabolism.” Peters is also on the ICNF International Steering Committee. Seefeldt co-chaired the session on Biochemistry of Nitrogen Fixation and presented recent work in a talk entitled, “Insights into the Nitrogenase Mechanism.” Seefeldt is a member of the ICNF Program Advisory Committee and the ICNF Local Organizing Committee. Harwood co-chaired the session on Microbiology & Synthetic Biology and is a member of the ICNF Program Advisory Committee. Program details can be viewed at https://sites.google.com/a/lbl.gov/icnf/home.

 

Get to know EFRC scientists tackling energy challenges in Winter 2015 Frontiers in Energy Research
BETCy Newsletter
February, 2016

Scientists Rhesa Ledbetter, a graduate student in the BETCy EFRC laboratory of Lance Seefeldt at Utah State University, currently sits on the editorial board of the EFRC newsletter, Frontiers in Energy Research. Rhesa’s recent article in Frontiers profiles five EFRC scientists and explores how family, teachers, and a young inmate have inspired their work. A synopsis of her article follows.

“EFRCs are composed of diverse individuals spanning a wide range of backgrounds who have a common vision of overcoming global energy challenges. A few individuals with a focus in the biological sciences recently shared their backgrounds and thoughts on working in an EFRC."

Their stories are featured in the Frontiers in Energy Research article, “Getting to know scientists undertaking energy challenges.” Anne-Frances Miller, a BETCy Thrust Leader, was one of those highlighted. The article reveals how EFRC scientists bring past experiences and unique perspectives together for the common good of reaching energy solutions for the future.” The article is in Winter 2015 issue of Frontiers in Energy Research.

 

BETCy gains feedback at Scientific Advisory Board meeting
BETCy News Release
May, 2015

Board Meeting April 2015 BETCy hosted its first meeting with its Scientific Advisory Board at the University of Georgia April 13-14, 2015. The Center gained valuable feedback and perspective, leveraging the expertise from the Board. “The meeting was a great success,” said BETCy Director John Peters, “At all our meetings, PIs and key personnel have shown a high level of enthusiasm resulting in strong synergy and early productivity. Since our Center was established only nine months ago, this Advisory Board meeting was a good opportunity to gain insight from our Board early in the game.”

The BETCy Scientific Advisory Board is chaired by Greg Ferry from Pennsylvania State University. Members include Robert Blankenship (Washington University), Dale Edmondson (Emory University), Mary Lidstrom (University of Washington), Bill Metcalf (University of Illinois, Mike Seibert (National Renewable Energy Laboratory) and Rolf Thauer (Max Planck Institute, Marburg).

On day one, BETCy research groups met individually, presented highlights of recent accomplishments to the group and finished by formulating a roadmap for publications within a 6 – 12 month timeframe. The Scientific Advisory Board joined on day two and heard presentations that summarized BETCy management structure and a detailed description of scientific accomplishments. The successful two day meeting concluded with a positive review from the Board of the Center’s early progress.

 

BETCy EFRC featured in Confluence Magazine
MSU College of Letters & Science
March, 2015

NREL Workshop The Montana State University-based Biological Electron Transfer and Catalysis Center (BETCy) was featured in the latest edition of the MSU College of Letters & Sciences "Confluence" magazine. (see magazine page 27)

"MSU will serve as the lead institution on a new $10 million, four-year project to form a research center focused on in- novative energy research. Chemistry professor John Peters is the principal investigator on the proposal and will direct the Bozeman-based center." DOWNLOAD TO READ MORE »

 

 

BETCy Team members collaborate on research methodologies at NREL workshop
BETCy News Release
February, 2015

NREL WorkshopScientists from the Biological Electron Transfer and Catalysis (BETCy) Energy Frontier Research Center (EFRC) recently met at the National Renewable Energy Laboratory (NREL) in Golden, Colorado. The five-day workshop was designed to build team synergy and give team members the opportunity to share methodologies. The goal was to develop new strategies first hand in the laboratory for moving forward on the Center’s goal of researching bifurcating enzymes.

The November program focused on redox properties and transient absorption spectroscopy of EFRC bifurcating flavoenzymes. Developing these tools will enable new mechanistic details toward understanding how these unique enzymes operate.

The workshop was led by Dr. Robert Usselman of Montana State University and Dr. David Mulder of NREL. Dr. Usselman is a research scientist in the John Peters Lab, and Dr. Mulder is a research scientist in NREL’s Bioenergy Science and Technology Division. Mulder received his PhD from MSU, where he was also a member of the Peters Lab.

Participating scientists hailed from NREL, MSU, and the University of Kentucky. All three institutions are key partners in the BETCy EFRC. NREL WEBSITE »

 

Montana State's Stephen Keable receives DOE Graduate Student Research Award
US Department of Energy
November, 2014

Stephen Keable, a graduate student in chemistry/biochemistry at Montana State University and a member of the John Peters Lab group, has received a Graduate Student Research award from the U.S. Department of Energy’s Office of Science. The program is designed to prepare graduate students for science, technology, engineering or mathematics (STEM) careers in areas that are critically important to the DOE Office of Science mission.

Keable will receive supplemental funding to conduct part of his thesis research at Oak Ridge National Laboratory in Oak Ridge, TN. His appointment at ORNL will run from Feb. 23 to July 30. Keable will be working with Dr. Dean Myles and Dr. Flora Meilleur on neutron crystallography experiments. Learn more about the Office of Science Graduate Student Research (SCGSR) program. MORE »

 

Several BETCy investigators are highlighted in the November 2014 issue of the EFRC newsletter
Energy Frontiers Research Centeres (EFRC) Newsletter
November, 2014

Two BETCy Principal Investigators are featured in an article on mentoring, Caroline Harwood, BETCy Thrust 2 Co-leader, and Pin-Ching Maness, BETCy Associate Director of Project Management. John Peters, BETCy Director, is featured in an article on EFRC directors. This article was authored by Kathryn Fixen, a member of the EFRC Newsletter Editorial Board and postdoctoral fellow in Caroline Harwood’s BETCy research group. MORE »

 

MSU Scientists lead $10 million energy research project
Bozeman Daily Chronicle
June 24, 2014

Montana State University is leading a group of scientists who have won a $10 million, four-year federal research grant to hunt for breakthroughs in producing more energy from biofuels. Scientists from MSU and six other institutions banded together to win one of 10 U.S. Energy Department grants, out of more than 200 competing proposals. MORE »

 

USU on team awarded $10M DOE grant
Utah State University
June 23, 2014

Biochemistry professor Lance Seefeldt leading USU efforts in basic energy science Utah State University is part of a seven-institution team that’s one of 32 projects selected nationally for a U.S. Department of Energy program aimed at accelerating scientific breakthroughs needed to build a new energy economy. DOE secretary Ernest Moniz announced the awards June 18, 2014. MORE »