[extropy-chat] NANO/ID: Spooky nanowire crappying bacteria...

[Mike Lorrey]

Okay. Either these little guys were engineered by a crypto dirt
civilization, or there may be something to ID. What is the evolutionary
point of a bacteria that craps conductive nano-wires?

Bacteria grow conductive wires

 
Chappell Brown    
EE Times 
(08/08/2005 9:00 AM EDT)  

 
Peterborough, N.H. - Already being intensely studied as an agent for
cleaning up toxic waste, a strain of bacteria has now surprised
researchers with its ability to build conducting nanowires.

The long, very thin wires are unprecedented in biological systems, says
the microbiologist who discovered the bacteria and the wires'
conductivity. They completely change science's understanding of how
microbes handle electrons, he said.

Derek Lovley and his colleagues at the University of Massachusetts
(Amherst, Mass.) reported observing and measuring the conductivity of
long wires, 3 to 5 nanometers in diameter, emanating from the Geobacter
bacteria.

Exactly what the wires are made of is still under investigation, but
the gene that codes for them has been identified, Lovley said. That
opens up the possibility of using genetic engineering and systems
biology to manufacture wires with predetermined properties.

"The desirable properties will most likely be specified by particular
engineering applications," he said. Methods for predicting the
structures that would yield the desired properties, he said, "may
include those that would be classified under systems biology."

Geobacter is common, appearing in soils and at the bottom of rivers.
Since it uses metals, rather than oxygen, for respiration, it has
become useful in cleaning up toxic waste, including uranium that has
seeped into groundwater.

Lovley discovered the bacteria in the mid-1980s, and the organisms have
been thoroughly studied, so finding the thin conducting nanowires
emanating from their outer coat was unexpected. But it explains
Geobacter's ability to remove metals from soil and water. A key step in
its metabolism is the transfer of electrons from its interior to metals
in its surroundings. Until now, it was unknown how Geobacter
accomplished the task.

The Department of Energy has been the main supporter of Lovley's work
over the past two decades. "The microbial world never stops surprising
us," said Aristides Patrinos, associate director of the DOE's Office of
Biological and Environmental Research. "This discovery illustrates the
continuing relevance of the physical sciences to today's biological
investigations."

Patrinos said the bacteria may organize to form minipower grids in the
soil by linking up via the nanowires. That type of organized behavior
might also lead to ultrasmall environmental sensors or novel ways to
bioengineer nanocircuits.

The ability of the bacteria to link their nanowires has been observed
in Lovley's lab. The hairlike wires emanating from the bacteria had
been seen previously, but their conducting function was discovered via
atomic-force microscope techniques.

Gemma Ruegera, a microbiologist, worked with physicists Mark Tuominen
and Kevin McCarthy to probe the electrical properties of the tiny
wires. Their role in electron transfer was confirmed by genetically
altering the bacteria so that they no longer produced the wires. The
modified bacteria were unable to transfer electrons, the researchers
reported.

 


Mike Lorrey
Vice-Chair, 2nd District, Libertarian Party of NH
Founder, Constitution Park Foundation:
http://constitutionpark.blogspot.com
Personal/political blog: http://intlib.blogspot.com

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com