Almost all living things breathe oxygen to get rid of excess electrons when converting nutrients into energy. However , without access to oxygen, soil bacteria that live in the deep oceans or are buried underground for billions of years have evolved a way of breathing “breathing minerals”, via tiny protein filaments. called nanowires.
The natural world has its own electrical grid that is made up of a global network of tiny nanowires generated by bacteria in the soil and oceans that ‘breathe’ by exhaling excess electrons. Now, in a new study published in the journal Nature Communications, a team of scientists from Yale University in the United States has discovered that light can be a surprising ally in promoting this electronic activity within biofilm bacteria. They found that exposing bacteria-produced nanowires to light produced up to a 100-fold increase in electrical conductivity.
nature’s power grid
The Yale researchers looked at nature’s “electrical grid” and how light created electronic activity within biofilm bacteria. According to experts, this study has the potential for the effective production of value-added chemicals, biofuels and biodegradable materials.
For the study, exposing bacteria-producing nanowires to light found up to a 100-fold increase in electrical conductivity.
“The dramatic current increases in nanowires exposed to light show a stable and robust photocurrent that persists for hours,” explained Nikhil Malvankar, Associate Professor of Molecular Biophysics and Biochemistry (MBB) at the Yale Institute for Microbial Sciences on Campus Yale West and co-author of the research.
A somewhat special photosynthesis
This was quite a surprise, since most of the bacteria in the experiment exist deep underground, far from the reach of light. The researchers believe that a metal-containing protein known as cytochrome OmcS, which forms bacterial nanowires, acts as a natural photoconductor.
“It’s a completely different form of photosynthesis, ” Malvankar said. “Here, the light is accelerating the bacteria’s respiration due to the rapid transfer of electrons between the nanowires.”
This respiration ‘breathing minerals’ through tiny protein filaments called nanowires therefore produces a substantial and surprising increase in electrical current. Now, Malvankar’s lab is exploring how the discovery of this development could be used to spur the growth of optoelectronics and even capture methane – a greenhouse gas known to contribute to climate change – helping in the fight against global warming. , which is becoming more and more evident on our planet.
It seems that nature is once again offering us a hand to provide solutions to one of the most pressing problems of our time: climate change.
Referencia: “Microbial biofilms as living photoconductors due to ultrafast electron transfer in cytochrome OmcS nanowires” by Jens Neu, Catharine C. Shipps, Matthew J. Guberman-Pfeffer, Cong Shen, Vishok Srikanth, Jacob A. Spies, Nathan D. Kirchhofer, Sibel Ebru Yalcin, Gary W. Brudvig, Victor S. Batista and Nikhil S. Malvankar, 7 September 2022, Nature Communications.