Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > UMass Amherst Researchers Reveal Mechanism of Novel Biological Electron Transfer

Abstract:
When researchers at the University of Massachusetts Amherst led by microbiologist Derek Lovley discovered that the bacterium Geobacter sulfurreducens conducts electricity very effectively along metallic-like "microbial nanowires," they found physicists quite comfortable with the idea of such a novel biological electron transfer mechanism, but not biologists.

UMass Amherst Researchers Reveal Mechanism of Novel Biological Electron Transfer

Amherst, MA | Posted on March 19th, 2013

"For biologists, Geobacter's behavior represents a paradigm shift. It goes against all that we are taught about biological electron transfer, which usually involves electrons hopping from one molecule to another," Lovley says. "So it wasn't enough for us to demonstrate that the microbial nanowires are conductive and to show with physics the conduction mechanism, we had to determine the impact of this conductivity on the biology."

"We have now identified key components that make these hair-like pili we call nanowires conductive and have demonstrated their importance in the biological electron transport. This time we relied more on genetics. I think most biologists are more comfortable with genetics rather than physics," Lovley adds.

"From my perspective, this is huge. It really clinches a big question. We overturned the major objection the biologists were making and confirmed the assumption in our earlier work, that real metallic-like conductivity is taking place."

Findings are described in an early online issue of mBio, the open-access journal of the American Society for Microbiology. In addition to Lovley, the UMass Amherst team includes first author Madeline Vargas, with Nikhil Malvankar, Pier-Luc Tremblay, Ching Leang, Jessica Smith, Pranav Patel, Oona Snoeyenbos-West and Kelly Nevin.

In 2011, Lovely's group discovered a fundamental, previously unknown property of pili in Geobacter. They found that electrons are transported along the pili via the same metallic-like conductivity found in synthetic organic materials used in electronics. Electrons are conducted over remarkable distances, thousands of times the cell's length. But exactly how the pili accomplished this wasn't clear.

They knew that the conductivity of synthetic conducting organic materials can be attributed to aromatic ringed structures which share electrons, suspended in a kind of a cloud that allows the overlapping electrons to easily flow. It seemed possible that amino acids, which have similar aromatic rings, might serve the same function in biological protein structures like pili. Lovley's team looked for likely aromatic amino acid targets and then substituted non-aromatic amino acids for the aromatic ones to see if this reduced the conductivity of the pili.

It worked. The re-engineered pili with non-aromatic compounds substituted for aromatic ones looked perfect and unchanged under a microscope, but now they no longer functioned as wires. "This new strain is really bad at what Geobacter does best," Lovley says. "Geobacter is known for its ability to grow on iron minerals and for generating electric current in microbial fuel cells, but without conductive pili those capabilities are greatly diminished."

"What we did is equivalent to pulling the copper out of an extension cord," he adds. "The cord looks the same, but it can't conduct electricity anymore."

The ability of protein filaments to conduct electrons in this way not only has ramifications for scientists' basic understanding of natural microbial processes but practical implications for environmental cleanup and the development of renewable energy sources as well, he adds. Lovley's UMass Amherst lab has already been working with federal agencies and industry to use Geobacter to clean up groundwater contaminated with radioactive metals or petroleum and to power electronic monitoring devices with current generated by Geobacter.

His group has also recently shown that Geobacter uses its nanowires to feed electrons to other microorganisms that can produce methane gas. This is an important step in the conversion of organic wastes to methane, which can then be burned to produce electricity.

As more states, including national leader Massachusetts, pass laws to prevent hospitals, universities, hotels and large restaurants from disposing of food waste in landfills, Geobacter's role in producing methane could be part of the solution for how to deal with this waste. The Massachusetts law goes into effect in 2014. "Waste to methane is a well developed green energy strategy in Europe and is almost certain to become more important here in Massachusetts in the near future," Lovley notes.

Funding for this work was from the U.S. Office of Naval Research and the Department of Energy.

####

For more information, please click here

Contacts:
Janet Lathrop

413-545-0444

Copyright © University of Massachusetts at Amherst

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

A nanoscale wireless communication system via plasmonic antennas: Greater control affords 'in-plane' transmission of waves at or near visible light August 27th, 2016

Forces of nature: Interview with microscopy innovators Gerd Binnig and Christoph Gerber August 26th, 2016

A promising route to the scalable production of highly crystalline graphene films August 26th, 2016

Graphene under pressure August 26th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Analog DNA circuit does math in a test tube: DNA computers could one day be programmed to diagnose and treat disease August 25th, 2016

New approach to determining how atoms are arranged in materials August 25th, 2016

Johns Hopkins scientists track metabolic pathways to find drug combination for pancreatic cancer August 25th, 2016

New electrical energy storage material shows its power: Nanomaterial combines attributes of both batteries and supercapacitors August 25th, 2016

Discoveries

A promising route to the scalable production of highly crystalline graphene films August 26th, 2016

Graphene under pressure August 26th, 2016

Nanofur for oil spill cleanup: Materials researchers learn from aquatic ferns: Hairy plant leaves are highly oil-absorbing / publication in bioinspiration & biomimetics / video on absorption capacity August 25th, 2016

Unraveling the crystal structure of a -70 Celsius superconductor, a world first: Significant advancement in the realization of room-temperature superconductors August 25th, 2016

Announcements

A nanoscale wireless communication system via plasmonic antennas: Greater control affords 'in-plane' transmission of waves at or near visible light August 27th, 2016

Forces of nature: Interview with microscopy innovators Gerd Binnig and Christoph Gerber August 26th, 2016

A promising route to the scalable production of highly crystalline graphene films August 26th, 2016

Graphene under pressure August 26th, 2016

Military

New electrical energy storage material shows its power: Nanomaterial combines attributes of both batteries and supercapacitors August 25th, 2016

Nanoparticles that speed blood clotting may someday save lives August 23rd, 2016

Curbing the life-long effects of traumatic brain injury August 19th, 2016

Lab team spins ginger into nanoparticles to heal inflammatory bowel disease August 19th, 2016

Environment

Nanofur for oil spill cleanup: Materials researchers learn from aquatic ferns: Hairy plant leaves are highly oil-absorbing / publication in bioinspiration & biomimetics / video on absorption capacity August 25th, 2016

Researchers watch catalysts at work August 19th, 2016

Down to the wire: ONR researchers and new bacteria August 18th, 2016

SLAC, Stanford gadget grabs more solar energy to disinfect water faster: Plopped into water, a tiny device triggers the formation of chemicals that kill microbes in minutes August 15th, 2016

Energy

New electrical energy storage material shows its power: Nanomaterial combines attributes of both batteries and supercapacitors August 25th, 2016

Lehigh engineer discovers a high-speed nano-avalanche: New findings published in the Journal of Electrochemical Society about the process involving transformations in glass that occur under intense electrical and thermal conditions could lead the way to more energy-efficient glas August 24th, 2016

New flexible material can make any window 'smart' August 23rd, 2016

Researchers reduce expensive noble metals for fuel cell reactions August 22nd, 2016

Nanobiotechnology

Analog DNA circuit does math in a test tube: DNA computers could one day be programmed to diagnose and treat disease August 25th, 2016

Nanofiber scaffolds demonstrate new features in the behavior of stem and cancer cells August 25th, 2016

Johns Hopkins scientists track metabolic pathways to find drug combination for pancreatic cancer August 25th, 2016

50 years after the release of the film 'Fantastic Voyage,' science upstages fiction: Science upstages fiction with nanorobotic agents designed to travel in the human body to treat cancer August 25th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic