Electrically conductive bacteria hide tiny stacks and great advances in the medical field

Scientists have made a startling discovery about how strange bacteria living in soil and sediment can drive electricity. The researchers determined that, thanks to a seamless biological structure never before seen, bacteria could cooperate to miniaturize electronics, create powerful but tiny batteries, build wireless stimulators and develop many other medical applications. advances.

Scientists believed that Geobacter sulfursucens conducted electricity through common appendages resembling hair called pili. Instead, a researcher from the University of Virginia's Faculty of Medicine and his collaborators determined that the bacteria transmit electricity through perfectly ordered fibers, made up of a totally different protein . These proteins surround a nucleus of metal-containing molecules, much like an electrical cord containing wires. This "nanowire", however, is 100,000 times smaller than the width of a human hair.

Researchers believe that this tiny but well-ordered structure could be extremely useful, whether to harness the power of bioenergy, reduce pollution or create biological sensors. It could actually serve as a bridge between electronics and living cells.

"There are all kinds of implanted medical devices that are connected to tissues, like pacemakers with wires, and this could lead to applications in which miniature devices are actually connected by these protein filaments," said Edward H. Egelman, UVA, Ph. RE. "We can now imagine the miniaturization of many electronic devices generated by bacteria, which is pretty amazing."

Small but effective

Geobacterial bacteria play an important role in the soil, notably by facilitating the renewal of minerals and even by cleaning up radioactive waste. They survive in oxygen-free environments and use nanowires to get rid of excess electrons, which can be considered their equivalent to breathing. These nanowires have fascinated scientists, but it is only now that researchers at UVA, Yale, and the University of California, Irvine, have been able to determine how G. sulfurrucens uses these organic leads to convey electricity.

"Technology [to understand nanowires] Egalman, from the UVA Department of Biochemistry and Molecular Genetics, said Egelman, that is, it existed until about five years ago, when advances in cryogenic microscopy allowed a high resolution. ability to really understand at the atomic level the structure of these filaments. … So this is one of the many mysteries we've been able to solve with this technology, like the virus that can survive in boiling acid, and there will be others. "

He noted that by understanding the natural world, including small scale, scientists and manufacturers can obtain many valuable and useful information. "An example that comes to my mind is spider silk, made from proteins like these nanowires, but is stronger than steel," he said. "Over the course of billions of years of evolution, nature has developed materials with extraordinary qualities, and we want to take advantage of them."

The researchers published their results in the scientific journal Cell. The authors of the study were Wang Fengbin, Yangqi Gu, Patrick J. O. Brien, Sophia M. Yi, Sibel Ebru Yalcin, Vishok Srikanth, Shen Cong, Dennis Vu, Nicole L. Ing, Allon I. Hochbaum, Egelman and Nikhil S. Malvankar.