Programming interfacial electron transfer at Shewanella oneidensis – Magnetic biochar hybrids for selective tetracycline–ciprofloxacin co-removal

Biogenic FeS Reshapes microbial interactions to regulate acetogenesis in CO2-Fed microbial electrosynthesis.

Electrochemical induction of high performance electricity generation by novel marine electroactive Rossellomorea aquimaris MT01.

Real-time bioelectronic sensors based on electroactive bacteria with organic electrochemical transistors.

Electron shuttles (ESs) critically enhance microbial extracellular electron transfer (EET), a key biogeochemical process that drives iron cycling and the activation of nutrients like phosphorus. However, existing studies are largely qualitative, focusing on EET pathway identification or current density measurements without quantitatively resolving the underlying energetics. Here, we establish an atomic force microscopy-based single-cell and single-molecule force spectroscopy platform, enabling the first direct quantification of microbial-ES-mineral interfacial energies. We find that riboflavin amplifies the adhesion energy between Shewanella oneidensis MR-1 and ferrihydrite-phosphate complex from 0.81 ± 0.064 fJ to 1.92 ± 0.049 fJ, accelerating microbe-mineral bonding up to 5-fold and boosting electron utilization efficiency from 0.015-0.028 h-1 to 0.048-0.12 h-1 across diverse Fe(III) minerals. We further reveal riboflavin binding hotspots on outer membrane c-Cyts, with a binding free energy of -25.6 kJ mol-1. These thermodynamic findings facilitate EET, which in turn significantly enhances the bioavailability of iron and phosphorus. For the first time, we quantified microbial cell-mineral and ES-cell binding energetics, thereby bridging interfacial thermodynamics across molecular and cellular scales to establish a mechanistic basis for EET and its role in nutrient mobilization. Such insights open avenues for control of ES-mediated functions in nutrient cycling, pollutant transformation, and sustainable bioenergy.

Extracellular polymeric substance (EPS)-mediated biosynthesis is a sustainable route for heavy metal valorization into quantum dots (QDs), yet how the EPS protein secondary structure regulates QD properties remains undefined. Herein, EPS from Shewanella oneidensis MR-1 cultivated under flotation reagent stress was utilized to synthesize high-performance ZnS QDs. Sodium butyl xanthate exhibited the optimal induction effect, significantly lowering the α-helix/(β-sheet + random coil) ratio in EPS. This structural shift promotes a more extended network, serving as a spatially ordered template for rapid, uniform ZnS nucleation. Analyzing QD materials mediated by distinct EPS layers (LB-EPS and TB-EPS) across treatments revealed strong correlations of this ratio with their size uniformity and specific surface area. Conversely, the QD yield and fluorescence intensity were governed primarily by chemical group abundance and synergistic structural-chemical factors, respectively. This dual regulatory mechanism demonstrates that manipulating the EPS protein structure is as crucial as modulating its chemical composition for nanomaterial biosynthesis.

Non-photosynthetic microorganisms drive the transformation of bioinert emerging contaminants through photoinduced singlet oxygen production.

Photoelectron-driven modulation of carbon metabolism enhances hydrogen production in a ZnIn2S4-Shewanella oneidensis biohybrid system.

Voltage-dependent phenotypic switching in Shewanella oneidensis MR-1 shapes cellular surface behavior and electroactive biofilm performance

Red-light-activated living bacterial electron generator for on-demand drug release in colonic inflammation.

Redox-active antioxidants enable highly stable bio-electrochemical systems.

Synthetic biology is transforming how we understand and teach microbial energy metabolism. In a recent study (F. Li, B. Zhang, X. Long, H. Yu, et al., Nat Commun 16:2882, 2025, https://doi.org/10.1038/s41467-025-57497-z), the authors demonstrated a synthetic gene circuit that enables Shewanella oneidensis to produce and release phenazine-1-carboxylic acid, a redox-active metabolite that enhances extracellular electron transfer and electricity generation. This perspective highlights the significance of their work, focusing on how controlling the production of redox mediators provides new insights into microbial electron flow and bioelectronic design. Beyond its technological implications, this system also serves as a valuable educational case study for teaching principles of redox balance, gene regulation, and metabolic engineering. Viewing this advancement in the context of biology education underscores the potential of synthetic circuits to deepen our understanding of microbial metabolism and to promote interdisciplinary learning in microbiology, biotechnology, and engineering.

Biofilms formed by Shewanella oneidensis MR-1 are crucial for metal reduction, underpinning bioremediation and bioenergy applications, yet detailed structural insights into biofilm components remain limited. Here we show that MR-1 biofilms contain abundant filamentous networks, membrane vesicles, and distinct square-shaped aggregates, as revealed by cryo-electron tomography and cryo-electron microscopy. We further determine near-atomic resolution structures of three filament types: bacterial flagella and two distinct pili, PilA and MshA. We present high-resolution structures of an MshA pilus and a PilA pilus from Shewanella. Structural analyses show that MshA pili exhibit a balanced surface charge distribution and extensive solvent-accessible surface area, facilitating essential interactions within the biofilm matrix. Additionally, oxygen limitation markedly increases the abundance of extracellular filaments and protein aggregates, indicating adaptive responses to environmental stress. Our findings elucidate the fundamental architecture and roles of biofilm extracellular components and provide a structural foundation for engineering enhanced Shewanella strains.

Microorganism-based tumor therapy has attracted increasing interest due to the intrinsic tumor tropism and metabolic plasticity of certain bacterial species. However, their therapeutic efficacy is often hindered by insufficient metabolic activity within the tumor microenvironment and safety concerns associated with systemic administration. Here, we develop a biohybrid system, termed Ce6@PB@MR-1, to enhance the intrinsic tumor-targeting behavior of chlorin e6 (Ce6) and lactate-metabolizing capability of Shewanella oneidensis MR-1 (MR-1) through engineered material-microbe coupling. In this system, Prussian blue (PB) is metabolically precipitated onto the MR-1 surface during anaerobic respiration, forming an electron-mediating interface in which PB functions as an efficient exogenous electron acceptor to strengthen respiratory electron flux and accelerate the lactate metabolism of MR-1. The PB coating simultaneously attenuates bacterial immunogenicity, enabling the improved in vivo persistence and safety of MR-1. Furthermore, bioconjugated Ce6 enables 660 nm-triggered photodynamic therapy to induce immunogenic cell death and activate antitumor immune responses. In vivo, the biohybrid system achieves durable tumor eradication accompanied by a marked remodeling of the tumor microenvironment. This work establishes a metabolically assisted material-microbe hybridization framework that expands microbial functionality and offers a versatile strategy for developing safe and effective microbe-based cancer therapies.

ABSTRACT The integration of semiconductor nanomaterials with electroactive bacteria offers a promising strategy for enhancing light-driven biohybrid systems. However, the generation of reactive oxygen species (ROS) during photocatalysis poses a significant challenge, impairing microbial viability and reducing process efficiency. In this study, we developed a novel biohybrid system by sequentially biosynthesizing cadmium sulphide (CdS) nanoparticles and manganese oxide (Mn3O4) nanozyme on the surface of Shewanella oneidensis MR-1, creating an S. oneidensis-CdS@Mn3O4 composite. The CdS nanoparticles facilitated efficient light absorption and electron transfer, significantly enhancing hydrogen production under visible light irradiation. However, ROS accumulation (·OH, O2⁻·, and H2O2) induced oxidative stress, reducing bacterial viability and metabolic activity. To address this, Mn3O4 nanozyme were introduced, demonstrating robust ROS-scavenging capabilities, reducing hydrogen peroxide (H2O2) levels by 66.7%, superoxide radical (O2⁻·) by 60.7%, and hydroxyl radical (·OH) by a significant margin. As a consequence, hydrogen production by S. oneidensis-CdS@Mn3O4 reached 1203.60 µmol g-dcw⁻¹ after 70 h of visible-light irradiation, which was 2.6-fold higher than that of S. oneidensis-CdS. Furthermore, Mn3O4 preserved cell viability, maintained higher NADH/NAD⁺ ratios, and enhanced ATP levels, indicating improved metabolic efficiency. Structural characterization via scanning electron microscopy (SEM) energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) confirmed the successful synthesis of CdS and Mn3O4 on bacterial surfaces, while photoelectrochemical analysis verified retained photosensitivity. This study presents a simple yet effective strategy for mitigating ROS-induced damage in bio-semiconductor systems, offering insights into the design of more stable and efficient biohybrid platforms for sustainable energy production. Key points A biohybrid system (S. oneidensis-CdS@Mn3O4) was constructed by sequential biosynthesis of CdS and Mn3O4 nanozyme. Mn3O4 efficiently scavenged ROS, increasing hydrogen production by 2.6-fold compared to S. oneidensis-CdS.

Aerobic extracellular electron transfer in Shewanella spp.

Coupled photocatalytic–microbial strategy for efficient Cr(VI) and phenol remediation using hematite and Shewanella oneidensis

Deciphering the reduction mechanism of graphene oxide by Shewanella oneidensis and its enhancement via genetic engineering

Modular engineering strategy to enhance extracellular electron transfer in Shewanella oneidensis under acid stress

Cross-scale modeling of bacteria-contaminant spatiotemporal dynamics in 3D bioprinted hydrogel for dye biodegradation.