Machinery behind bacterial nanowires explained

Almost all living things breathe oxygen to get rid of excess electrons when converting nutrients into energy. Without access to oxygen, however, soil bacteria living deep under oceans or buried underground over billions of years have developed a way to eliminate electrons by “breathing minerals,” like snorkeling, through tiny protein filaments called nanowires.  

In previous research, a team led by Nikhil Malvankar, associate professor of Molecular Biophysics and Biochemistry at the Yale Microbial Sciences Institute, showed that nanowires are made up of a chain of heme molecules, just like hemoglobin in our blood, thrust into the environment to move electrons. But until now, no one had explained how individual bacteria made the nanowires.

Published in Cell Chemical Biology, scholars in the Mavlankar lab have now identified the unique group of genes that help assemble the nanowire. Led by lab member Cong Shen, the team systematically analyzed the roles of key proteins that make up the nanowire assembly machinery,  – identifying the single machinery responsible for making the wire. By changing the amount of key proteins in the machinery, the team made bacteria produce more nanowires and breathe faster. 

The findings mark an important next step in understanding the potential applications of bacterial nanowires in bioenergy, bioremediation, and bioelectronics for sensing environmental contaminants and mitigating climate change.

Other authors are lab members Aldo Salazar-Morales, Joey Erwin, Yangqi Gu, Anthony Coelho, Sibel Ebru Yalcin, and Fadel Samatey, along with Yale collaborators Kallol Gupta and Wonhyeuk Jung.

By Jon Atherton. Description of earlier research by Bill Hathaway.