Research Lab

Biochemistry and Bioenergetics of Heme Proteins

29673

Lab Members

Research Interests

The research team uses complementary biochemical and biophysical methods to study the respiratory chain of electrogenic bacteria, which couple their oxidative metabolism to the reduction of extracellular electron acceptors such as toxic/radioactive metals or electrode surfaces. The structural and functional characterization of key electron transfer components, particularly multiheme cytochromes and bacterial conductive filaments, permits the elucidation of the bacteria’s respiratory pathways and endows their rational engineering for optimization of Geobacter-based biotechnological (bioremediation, microbial electrosynthesis, bioenergy) and bioelectronic applications.

Research Highlights

Exploring electron transfer proteins of electrogenic bacteria for sustainable biotechnological applications

The electrogenic bacterium Geobacter sulfurreducens transfers electrons to the cell’s exterior and produces electricity in microbial fuel cells. The outer membrane cytochrome c OmcF is involved in this respiratory pathway. The molecular bases for the modulation of OmcF’s redox behaviour were determined. Measurements of electron production and electron flux rates revealed
that the bacterial electron flow is regulated by increasing the reduced/oxidized ratios of the cytochromes in response to a decrease of the oxidative activity of the extracellular metals. The electron flow is independent of the concentration and type of oxidant and results in ATP homeostasis.

Representative Projects

“Wired life: Exploring the unprecedented electron transfer paths revealed by bacterial electrically conductive filaments for bioenergy and bioelectronics applications“, FCT-MCTES, Total: €231,083, Carlos Salgueiro (PI)
“Redox Maze: Elucidation of bacterial extracellular electron transfer pathways for sustainable bio-based applications“, FCT-MCTES, Total: €49,900, Leonor Morgado (PI), Carlos Salgueiro (Co-PI)
“Look out over the wall: rational powering of microbial nanowires for sustainable bioenergy-based applications”, FCT-MCTES, Total and Unit funding: €220,459, Carlos Salgueiro (PI).

Selected Publications

Almeida, A; Turner, DL; Silva, MA; Salgueiro, CA. 2025. New insights in uranium bioremediation by cytochromes of the bacterium Geotalea uraniireducens. JOURNAL OF BIOLOGICAL CHEMISTRY, 301, DOI: 10.1016/j.jbc.2024.108090

Portela, PC; Shipps, CC; Shen, C; Srikanth, V; Salgueiro, CA; Malvankar, NS. 2024. Widespread extracellular electron transfer pathways for charging microbial cytochrome OmcS nanowires via periplasmic cytochromes PpcABCDE. Nature Communications, 15, DOI: 10.1038/s41467-024-46192-0

Ferreira, MR; Morgado, L; Salgueiro, CA. 2024. Periplasmic electron transfer network in Geobacter sulfurreducens revealed by biomolecular interaction studies. PROTEIN SCIENCE, 33, DOI: 10.1002/pro.5082

Portela, PC; Silva, MA; Almeida, A; Salgueiro, CA. 2024. Tweaking the redox properties of PpcA from Geobacter metallireducens with protein engineering. BIOCHEMICAL JOURNAL, 481, DOI: 10.1042/BCJ20240423

Fernandes, TM; Silva, MA; Morgado, L; Salgueiro, CA. 2023. Hemes on a string: insights on the functional mechanisms of PgcA from Geobacter sulfurreducens. JOURNAL OF BIOLOGICAL CHEMISTRY, 299, DOI: 10.1016/j.jbc.2023.105167

Antunes, JMA; Silva, MA; Salgueiro, CA; Morgado, L. 2022. Electron Flow From the Inner Membrane Towards the Cell Exterior in Geobacter sulfurreducens: Biochemical Characterization of Cytochrome CbcL. Frontiers in Microbiology, 13, DOI: 10.3389/fmicb.2022.898015

Karamash, M; Stumpe, M; Dengjel, J; Salgueiro, CA; Giese, B; Fromm, KM. 2022. Reduction Kinetic of Water Soluble Metal Salts by Geobacter sulfurreducens: Fe2+/Hemes Stabilize and Regulate Electron Flux Rates. Frontiers in Microbiology, 13, DOI: 10.3389/fmicb.2022.909109

Salgueiro, CA; Morgado, L; Silva, MA; Ferreira, MR; Fernandes, TM; Portela, PC. 2022. From iron to bacterial electroconductive filaments: Exploring cytochrome diversity using Geobacter bacteria. COORDINATION CHEMISTRY REVIEWS, 452, DOI: 10.1016/j.ccr.2021.214284

Morgado, L; Salgueiro, CA. 2022. Elucidation of complex respiratory chains: a straightforward strategy to monitor electron transfer between cytochromes. Metallomics, 14, DOI: 10.1093/mtomcs/mfac012