Electric microbes

Life is nothing but an electron looking for a place to rest‘ – Szent-Györgyi

The Reguera lab has led pioneer work describing the electric nature of some microbes and applications that harness their activities in bioremediation, nanotechnology and biomining. Current projects in the lab investigate the role of these microbes in the cycling of metals considered ‘endangered’ because they are essential components in electronics and high-tech materials yet they have a vulnerable supply chain. Electric microbes in the genus Geobacter have respiratory chains for the extraction of these metals from minerals and for their reductive mineralization into nanoparticles. With funds from the Geobiology program at the National Science Foundation, we are investigating how these bacteria mineralize cobalt and the impact of their activities in the cycling of this essential metal in the environment. We are also developing biomimetic interfaces that reconstruct the respiratory chains of these electric microbes in platforms for the reclamation of endangered metals from wastes. In addition, we work with industrial partners to develop electroactive biofilms on electrodes (‘bioelectrodes’) for the recycling and up cycling of wastewater.

Geobacter cells make their own protein nanowires to zap toxic metals and radionuclides and convert them into nanominerals. Learn about our work in this award-winning video “Zapping Nuclear Waste” and by reading MSU’s highlights of our research.

Remediation of agrochemicals

The more we pour the big machines, the fuel, the pesticides, the herbicides, the fertilizer and chemicals into farming, the more we knock out the mechanism that made it all work in the first place” – David R. Brower

Our work on electric microbes led us to investigate hitherto unknown roles of these bacteria in the remediation of agrochemicals (nutrients and pesticides) that are released in agricultural run-offs. We have a DOE-funded collaborative project with biochemists at MSU to investigate the respiratory chains that enable these activities. We are also working with colleagues in the department of Horticulture to investigate the complex microbial communities that control the bioremediation capacity of technologies designed to remove agrochemicals sustainably (spoiler alert: Geobacter bacteria are part of them!). Our goal is to provide farmers with treatment options of agricultural wastewater and recycling of irrigation water.

Geobacter bacteria play key roles in the solubilization of metals essential to plants and plant-associated microbiomes. They also contribute to the retention of nitrogen fertilizers in soils and are part of the microbiomes that can help us remove agrochemicals from agricultural run-offs.

Otic microbiome

Our bond with microbes is such that they are not so much riders, parasites, and assistants as part human. And we, it’s becoming increasingly clear, may need to begin thinking of ourselves as part microbe.”― Guy P. Harrison

We are funded by the Microbiome program of the Office of Naval Research to develop bacterial replacement therapies that can protect divers from barotrauma. We look at the middle ear with the eye of a microbial ecologist: as a fluctuating environment that is subjected to microbial immigration and elimination processes. Our studies challenged the entrenched dogma of a sterile middle ear and revealed instead that the otic mucosa harbors a complex bacterial community of oral ancestry. We use omics tools and cultivation approaches to learn about these unique microbiomes and develop approaches to manipulate their responses to chemical, physical and biological stressors, including infections.

Basic research into the otic microbiome informs of bacterial replacement therapies that can protect divers from barotrauma. This knowledge is also helping us understand how otic commensals cooperate to protect us from infections.