Geobacter in green, nanowires in gray, and ingrained hemes are displayed in yellow with electrons in blue. Credit: Sibel Ebru Yalcin, Nikhil Malvankar, and Ella Maru Studio
A global research team is investigating nanowires in consuming and methane-producing microorganisms to understand how these filaments allow electron exchange, which figures out methane production or usage. The groups diverse know-how will help decipher the complex pilus machinery associated with nanowire production.
The increasing temperatures threatening life on our planet are caused in part by microorganisms that produce 50% of climatic methane, a gas 30 times more powerful than CO2 at trapping heat. Remarkably, another type of microbe combats these rising temperature levels by consuming up to 80% of methane released from ocean sediments. How are some microbes methane manufacturers and others methane customers?
To fix this puzzle, a worldwide team of researchers, Nikhil Malvankar (Yale University, USA), Carlos Salgueiro (NOVA University of Lisbon, Portugal), Lisa Craig (Simon Fraser University, Canada), and Olivera Francetic (Institut Pasteur, France), have received among the 25 Human Frontier Science Program Awards for cutting edge, high-risk high-reward jobs.
The group will study the wire-like filaments made by electricity-producing Geobacter, which look like methane-eating microbes. These “nanowires” permit microbes to exchange electrons with their partners, with the instructions of existing figuring out whether methane is produced or consumed.
Nanowires were initially reported over twenty years back and till extremely recently were believed to be type IV pili. Malvankar lab recently revealed that the conductive filaments of Geobacter are in reality polymers of cytochrome proteins, which consist of metal-coordinating hemes that line up to develop a continuous path along which electrons travel. The role of the Geobacter pili might really be to assemble and secrete these cytochrome nanowires.
The groups cumulative knowledge in nanowires (Malvankar), heme proteins (Salgueiro), type IV pili (Craig) and bacterial secretion (Francetic) will help unwind how the complex pilus machinery assists microorganisms produce nanowires.