Biological complexity: wired bacteria (Introduction)

by David Turell , Thursday, March 24, 2016, 22:32 (3166 days ago) @ David Turell

They produce tiny protein polypeptide wires that carry electrons at high speed:-https://www.sciencedaily.com/releases/2016/03/160324104809.htm-"The discovery, featured in the current issue of Scientific Reports, describes the high-speed protein fiber produced by uranium-reducing Geobacter bacteria. The fibers are hair-like protein filaments called "pili" that have the unique property of transporting charges at speeds of 1 billion electrons per second.-"'This microbial nanowire is made of but a single peptide subunit," said Gemma Reguera, lead author and MSU microbiologist. "Being made of protein, these organic nanowires are biodegradable and biocompatible.-***-"How the nanowires function in nature is comparable to breathing. Bacterial cells, like humans, have to breathe. The process of respiration involves moving electrons out of an organism. Geobacter bacteria use the protein nanowires to bind and breathe metal-containing minerals such as iron oxides and soluble toxic metals such as uranium. The toxins are mineralized on the nanowires' surface, preventing the metals from permeating the cell.-***-"They are like power lines at the nanoscale," Reguera said. "This also is the first study to show the ability of electrons to travel such long distances -- more than a 1,000 times what's been previously proven -- along proteins."-"The researchers also identified metal traps on the surface of the protein nanowires that bind uranium with great affinity and could potentially trap other metals."-Comment: These bacteria need the wires to breathe. Did the bacteria appear with the wires when they evolved? I would think so. Once again, completeness without tiny steps of adaptation. Not Darwin.