The U.S. Naval Research Office funds microbial nanowire electronic materials.

Microbiologists at the University of Massachusetts at Amster recently discovered that bacteria can produce a new type of natural wire that will help researchers develop sustainable "green" conductive materials for the electronics industry as early as possible.
mBio, a major journal of the American Society for Microbiology, reported this week on research by Derek Lovley and his colleagues.
researchers studied microbial nanowires, which are used by bacteria to electrically connect to other microorganisms or minerals under natural conditions.
, as Lovley says, microbial nanowires are revolutionary electronic materials that have significant advantages over man-made materials.
chemically synthesized nanowires in the laboratory require toxic chemicals, high temperatures and/or expensive metals.
also requires a huge amount of energy.
contrary, natural microbial nanowires require high-volume production using only inexpensive renewable raw materials in room temperature bioreacters, while significantly reducing energy consumption.
addition, the final product does not contain toxic ingredients.
, microbial nanowires offer greater possibilities for the development of new multi-functional environmentally friendly materials, electronic devices and sensors.
is a major breakthrough in microbial nanowire technology.
methods described by the researchers in their paper will help to quickly find better electronic materials in nature.
, Lovley's lab had been using only one bacterium, sulfur-reducing bacillus, to study nanowires.
researchers say we studied only one type of bacillus in the early days because we wanted to understand the mysteries behind the bacteria's production of such tiny filaments.
now we are most interested in using nanowires as electronic materials and want to better understand the nature of applications suitable for practical applications.
when the lab began studying protein traces from other Bacillus species, they were surprised to find widespread conductivity.
, for example, a species recovered from uranium-contaminated soil can produce weaker conductive wires.
, however, another organism, metal-reduced Bacillus, happens to be the first isolated type of ground bacillus that produces nanowires that conduct 5,000 times more electrically than sulfur-reduced Bacillus.
a new study funded by the U.S. Naval Research Office, they did not directly study the metal-reducing Bacillus strain.
, they extracted the protein genes that make up the microbial nanowires.
and implant it with sulfur-reducing Bacillus.
, they changed the genetic properties of Bacillus sulphur-reducing Bacillus to produce a metal-reduced Bacillus protein, which produced wires that were far more conductive than the nanowires naturally produced by Bacillus sulfonate.
addition, Lovley said they had found that sulphur-reduced Bacillus carried silky genes with different types of bacteria.
makes it easier to produce diverse traces in the same microorganism and to study its properties under similar conditions.
added that we follow this approach to explore useful conductive materials in the microbial world.
there are a lot of fine silk genes in the microbial world, and now we can study the fine traces produced by their genes, even using microbes that have never been cultured before.
researchers attribute the ultra-high conductivity of metal-reducing Bacillus nanowires to their greater abundance of aromatic amino acids.
tightly stacked aromatic rings seem to be key to the conductivity of microbial nanowires, which means that the more aromatic rings there are, the better the electrons can move along the protein wire.
conductivity of metal-reducing Bacillus nanowires suggests that they may be good materials for the manufacture of conductive materials, electronic devices and sensors in the medical or environmental field.
more understanding of the nanowire conductivity mechanism could give us a clearer idea of how to use improved genes to make better wires, the authors said.
source: Microbial technology applications.