A discovery by scientists at the University of East
Anglia (UEA) could contribute to the development of systems
that use domestic or agricultural waste to generate clean
electricity. Recently published by the scientific journal,
Proceedings of the National Academy of Sciences (PNAS), the researchers have demonstrated for the first time the
mechanism by which some bacteria survive by 'breathing
rocks'. The findings could be applied to help in the
development of new microbe-based technologies such as
fuel cells, or bio-batteries, powered by animal or human
waste, and agents to clean up areas polluted by oil or
uranium.
“This is an exciting advance in our understanding
of bacterial processes in the Earth's sub-surfaces," said
Prof. David Richardson, of UEA's School of Biological
Sciences, who is leading the project. "It will also have
important biotechnological impacts. There is potential for
these rock-breathing bacteria to be used to clean-up
environments contaminated with toxic organic pollutants
such as oil or radioactive metals such as uranium. Use of
these bacteria in microbial fuel-cells powered by sewerage
or cow manure is also being explored.”
The vast proportion of the world's habitable
environment is populated by microorganisms which, unlike
humans, can survive without oxygen. Some of these
microorganisms are bacteria living deep in the Earth's
subsurface and surviving by 'breathing rocks' especially minerals of iron. Iron respiration is one of the most
common respiratory processes in oxygen-free habitats and
therefore has wide environmental significance.
Prof. Richardson said: “We discovered that the
bacteria can construct tiny biological wires that extend
through the cell walls and allow the organism to directly
contact, and conduct electrons to, a mineral. This means
that the bacteria can release electrical charge from inside
the cell into the mineral, much like the earth wire on a
household plug.”
Source: www.sciencedaily.com
ENVIS
CENTRE Newsletter Vol.7,Issue 4 October 2009
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