A widespread and ancient bacterial machinery assembles cytochrome OmcS nanowires essential for extracellular electron transfer

Cell chemical biology, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Language: Английский

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Cytochrome “nanowires” are physically limited to sub-picoamp currents that suffice for cellular respiration

Frontiers in Chemistry, Journal Year: 2025, Volume and Issue: 13

Published: March 12, 2025

Mineral-respiring microorganisms from hydrothermal vents to terrestrial soils express filaments that electrically connect intracellular respiration extracellular geochemistry. Filaments dubbed “cytochrome nanowires” (CNs) have been resolved by CryoEM, but whether they are the two-decades-long sought-after physiological “nanowires” remains unproven. To assess their functional competence, we analyzed biological redox conduction in all CNs computing driving forces presence of anti-cooperativities, reorganization energies with electronic polarizability, and Marcus rates for diffusive protein-limited flux models. The chain heme cofactors any CN must be densely packed realize weak (≤0.01 eV) coupling electron transfer, as evidenced a single Soret band produced coincidental absorptions on multiple hemes. Dense packing, turn, has three consequences: (1) limited (≤|0.3| due shared electrostatic microenvironments, (2) strong (≤0.12 anti-cooperativities would accentuate free energy landscape if linear arrangement did not dictate contra-thermodynamic oxidation order, (3) an entropic penalty is offset thioether ‘tethers’ hemes protein backbone. These linkages physically necessitate rate-throttling T-stacked motif (10-fold slower than other highly conserved slip-stacked motif). If sequence slip- had fastest known nanosecond at every step, micron-long filament carry 0.02 pA current 0.1 V, or 0.2 pA. Actual sub-optimal (≤10 2 -fold lower), sufficient conductivities cellular respiration, most thousands needed total metabolic flux. Reported once used argue metallic-like pili against cytochrome hypothesis now attributed remain inconsistent 10 –10 5 physical constraints through multiheme architectures.

Language: Английский

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Sensing devices fabricated with Escherichia coli expressing genetically tunable nanowires incorporated into a water-stable polymer

Biosensors and Bioelectronics, Journal Year: 2025, Volume and Issue: 278, P. 117378 - 117378

Published: March 14, 2025

Language: Английский

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Soft Materials and Devices Enabling Sensorimotor Functions in Soft Robots

Chemical Reviews, Journal Year: 2025, Volume and Issue: unknown

Published: March 31, 2025

Sensorimotor functions, the seamless integration of sensing, decision-making, and actuation, are fundamental for robots to interact with their environments. Inspired by biological systems, incorporation soft materials devices into robotics holds significant promise enhancing these functions. However, current systems often lack autonomy intelligence observed in nature due limited sensorimotor integration, particularly flexible sensing actuation. As field progresses toward soft, flexible, stretchable materials, developing such becomes increasingly critical advanced robotics. Despite rapid advancements individually devices, combined applications enable capabilities emerging. This review addresses this emerging providing a comprehensive overview that functions robots. We delve latest development technologies, actuation mechanism, structural designs, fabrication techniques. Additionally, we explore strategies control, artificial (AI), practical application across various domains as healthcare, augmented virtual reality, exploration. By drawing parallels aims guide future research robots, ultimately adaptability unstructured

Language: Английский

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Distinguishing the Contribution of Extracellular Electron Transfer in the Desulfovibrio caledoniensis-Induced Total Corrosion of Q235 Carbon Steel

Materials, Journal Year: 2025, Volume and Issue: 18(7), P. 1613 - 1613

Published: April 2, 2025

Microbially influenced corrosion (MIC) in anaerobic environments accounts for many severe failures and losses different industries. Sulfate-reducing bacteria (SRB) represent a typical class of corrosive microorganisms capable acquiring electrons from steel through extracellular electron transfer processes, thereby inducing electrical microbially (EMIC). Although prior research has underscored the significance transfer, contribution EMIC to whole MIC not been comprehensively studied. In this study, Q235 coupons were employed an H-shaped electrochemical cell conduct coupon immersion experiments, aiming determine overall MIC. The experiments conducted under two distinct carbon source conditions: 100% (CS) 1% CS environments. It was observed that biotic electrodes exhibited significantly higher cathodic currents, with most pronounced biological activity detected medium. voltammetric responses before after changes medium confirmed biocatalytic capability attached biofilm stimulating reaction. proportion calculated using linear polarization resistance, revealing trend over time. Additionally, weight loss tests indicated total approximately 27.69%. Furthermore, results demonstrated while rate lower environment, increased 37.68%.

Language: Английский

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Ultrahigh-mobility microbial cytochrome nanowires generate power from humidity

Research Square (Research Square), Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 12, 2024

Mixed electronic-ionic conductors are crucial for various technologies, including harvesting power from humidity in a durable, self-sustainable, manner unrestricted by location or environment^1,2. Biological proteins have been proposed as mixed 50 years^3,4. Recently, Geobacter sulfurreducens pili filaments claimed to act nanowires generate power^5,6. Here, we show that the is generated G. sulfurreducens-produced cytochrome OmcZ 20,000-fold higher electron conductivity than pili⁷. Remarkably, ultrahigh and proton mobility (>0.25 cm2/Vs), owing directional charge migration through seamlessly-stacked hemes charged, hydrogen-bonding surface, respectively. AC impedance spectroscopy DC measurements using four-probe van der Pauw back-gated field-effect-transistor devices reveal increases carrier 30,000-fold. Cooling halves activation energy, thereby accelerating transport. Electrochemical identify voltage mobilities required switch pure electronic conduction generation. The high aspect ratio (1:1000) hydrophilic nanowire surface captures moisture efficiently reduce oxygen reversibly, generating large potentials (>0.5 V) necessary sustain power. Our studies establish new class of biologically-synthesized, low-cost high-performance mixed-conductors key design principles improving output highly-tunable protein structures.

Language: Английский

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Recent Developments in Application of Nanofibers

Processes, Journal Year: 2024, Volume and Issue: 12(9), P. 1894 - 1894

Published: Sept. 4, 2024

Technological advancements in nanofibers and production technologies have led to being applied various applications. Nanofibers are produced by a variety of techniques such as electrospinning, drawing, self-assembly, phase separation, others. Electrospinning is widely used due its versatility scalability. Nanofiber other still limited the laboratory scale, hence dominance electrospinning. The has seen them applications health, protection, clothing, filtration, packaging, electronics. Their large surface area, small diameters, porous structures make good materials these diverse fields. incorporated with nanoparticles enhance stability. In biomedical applications, drug delivery systems, wound healing, tissue engineering because their biocompatibility biodegradability. fields like porosity, flexibility. These properties also highly effective where size area allow efficiently remove significant number contaminants. Additionally, utilized flexible electronics, enhancing comfort wearable devices. Biopolymers adopted address environmental health concerns traditional nanofiber materials. biodegradable biocompatible; however, stability can be affected conditions. This work highlights nanofibers, especially environmentally friendly water treatment, technical textiles.

Language: Английский

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Redox Conduction Through Cytochrome ‘Nanowires’ Can Sustain Cellular Respiration

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: April 3, 2024

Abstract Micron-scale electron transfer through polymeric cytochrome ‘nanowires’ powers prokaryotic life from hydrothermal vents to terrestrial soils in ways not fully understood. Herein, six reduction potentials recently reported spectroelectrochemistry are each assigned with <0.04 eV the cryogenic microscopy structure of hexa-heme homopolymeric outer-membrane type S (OmcS) Geobacter sulfurreducens using hybrid quantum/classical computations. The unambiguous assignments define a reversible free energy ‘roller-coaster’ that is dynamically modulated by <0.1 V under flow electrons due redox cooperativities between adjacent hemes. A physiologically relevant tens hundreds filaments predicted suffice for cellular respiration pairing, context non-adiabatic Marcus theory, landscape reorganization energies account active site or protein-water electronic polarizability, and couplings characteristic highly conserved heme packing motifs. General considerations on protein comparison all known suggest mechanistic insights broadly applicable multi-heme cytochromes kingdoms life.

Language: Английский

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Activation energy measurements to determine metabolic bottlenecks of a bioelectrochemical system studied using microfluidics and the Arrhenius equation

Published: July 26, 2024

To target development of bioelectrochemical systems, we developed an advanced microfluidic method to identify reaction bottlenecks in the metabolic activity a pure-culture Geobacter sulfurreducens electroactive biofilm (EAB). The system was devised include perpendicular flow orientation for improved boundary layer uniformity and combined with embedded 3-electrode accurately apply constant potential during entire experimental duration. A 3-sensor temperature control provided basis accurate pulsing, which modified EAB over short time intervals relative bacterial doubling rate. system, together unique ability hydrodynamic, electrochemical, thermal conditions, used as Arrhenius approach obtain activation energy barrier values at different growth times, acetate concentrations, rates. results indicated that overall after 1 month were related electron transfer through extracellular cytochrome c. After further matured 4 months old, bottleneck appeared switch enzyme-driven oxidation. Based on this hypothesis, observed 4-months, strong increases effective enzyme concentration primarily obtained by increasing rate, secondarily concentration.

Language: Английский

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Component, mechanisms, ecological effect and applications of metastable iron biogeobattery: A review

International Biodeterioration & Biodegradation, Journal Year: 2024, Volume and Issue: 198, P. 105984 - 105984

Published: Dec. 10, 2024

Language: Английский

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