Introducing extracellular electron transfer pathways into heterologous organisms offers the opportunity to explore fundamental biogeochemical processes and biologically alter redox states of exogenous metals for various applications. While expression MtrCAB nanoconduit from Shewanella oneidensis MR-1 permits in Escherichia coli, low flux absence growth these cells limits their practicality such Here we investigate how rate Fe(III) cell survival engineered E. coli are affected by mimicking...

Microbial electrosynthesis is an emerging technology with the potential to simultaneously store renewably generated energy, fix carbon dioxide, and produce high-value organic compounds. However, limited understanding of route electrons into cell remains obstacle developing a robust microbial platform. To address this challenge, we leveraged native extracellular electron transfer pathway in Shewanella oneidensis MR-1 connect electrode intracellular reduction reaction. The system uses Mtr...

Bacterial microcompartments (BMCs) are nanometer-scale organelles with a protein-based shell that serve to colocalize and encapsulate metabolic enzymes. They may provide range of benefits improve pathway catalysis, including substrate channeling selective permeability. Several groups working toward using BMC shells as platform for enhancing engineered pathways. The microcompartment Haliangium ochraceum (HO) has emerged versatile modular system can be expressed assembled outside its native...

Abstract Introducing an electronic interface into Escherichia coli will allow its enormous synthetic biology toolkit to be leveraged in bioelectrochemical applications. While E. expressing the Mtr pathway of Shewanella oneidensis MR‐1 transfer electrons anode, it has remained unclear if this current production alters intracellular state , which is a critical requirement for bioelectronic technologies. Here we address by characterizing Mtr‐expressing and effects on cellular viability,...

Introduction of the electron transfer complex MtrCAB from Shewanella oneidensis MR-1 into a heterologous host provides modular and molecularly defined route for electrons to be transferred an extracellular inorganic solid. However, Escherichia coli strain expressing this pathway displayed limited control expression impaired cell growth. To overcome these limitations improve transfer, we used E. with more tunable induction system panel constitutive promoters generate library strains that...

Bacterial microcompartments (BMCs) are self-assembling protein shell structures that widely investigated across a broad range of biological and abiotic chemistry applications. A central challenge in BMC research is the targeted capture enzymes during assembly. While crystallography cryo-EM techniques have been successful determining structures, there has only limited success visualizing location BMC-captured enzyme cargo. Here, we demonstrate opportunity to use small-angle X-ray scattering...

ABSTRACT Microbial electrosynthesis (MES) is a sustainable approach to chemical production from CO 2 and clean electricity. However, limitations in electron transfer efficiency gaps understanding of pathways MES systems prevent full realization this technology. Shewanella oneidensis could serve as an biocatalyst because it has well-studied, efficient transmembrane pathway. A key first step organism be reduction formate. we report that wild-type S. does not tolerate high levels In work,...

Many bioelectrochemical systems (BESs) harness the ability of electrode-active microbes to catalyze reactions between electrodes and chemicals, often perform useful functions such as wastewater treatment, fuel production, biosensing. A microbial cell (MFC) is one type BES, which generates electric power through respiration with an anode electron acceptor, typically oxygen reduction at cathode provide terminal acceptor. Oxygen intrusion into MFCs viewed detrimental because it competes anodes...

Abstract Previous transcriptomic profiling of Shewanella oneidensis MR‐1 had suggested that electron transfer to an anode in a bioelectrochemical system may induce general stress response (similar heat‐shock response) and/or increase protein turnover rates. Analysis this microbe grown with wide variety acceptors also indicated be related the redox potential terminal acceptor. To investigate whether electrodes can and turnover, S. was at potentiostatically poised five potentials versus...

ABSTRACT Extracellular electron transfer is a process by which bacterial cells can exchange electrons with redox-active material located outside of the cell. In Shewanella oneidensis , this natively used to facilitate respiration using extracellular acceptors such as Fe(III) or an anode. Previously, it was demonstrated that be drive microbial electrosynthesis (MES) 2,3-butanediol (2,3-BDO) in S. exogenously expressing butanediol dehydrogenase (BDH). Electrons taken into cell from cathode are...

Although the term 'Biocomputing' may bring to mind biological replacements of silicon processors; this type application is far in future. Use bacteria-based Biocomputing for biosensors and industrial fermentation control, however, presently attainable by using genetically-engineered bacterial cells that can process signals a logical operation via one or few pathways. Here, we refer these systems as 'Cellular Computing Circuits' focus on their possible future implementations. We also briefly...

The inherent complexity of biological systems is a major barrier to our understanding cellular physiology. Bacteria with markedly fewer genes than their close relatives, or reduced genome bacteria, are promising models less complexity. Reduced bacteria can also have superior properties for industrial use, provided the reduction does not overly restrict strain robustness. Naturally such as alphaproteobacterium

Abstract Bacterial microcompartments (BMCs) are nanometer-scale organelles with a protein-based shell that serve to co-localize and encapsulate metabolic enzymes. They may provide range of benefits improve pathway catalysis, including substrate channeling selective permeability. Several groups working toward using BMC shells as platform for enhancing engineered pathways. The microcompartment Haliangium ochraceum (HO) has emerged versatile modular system can be expressed assembled outside its...

Biosensors detect signals using biological sensing components such as redox enzymes and cells. Although cellular versatility can be beneficial for different applications, limited stability efficiency in signal transduction at electrode surfaces represent a challenge. Recent studies have shown that the Mtr electron conduit from Shewanella oneidensis MR-1 produced Escherichia coli to generate an exoelectrogenic model system with well-characterized genetic tools. However, means specifically...

Abstract Shewanella oneidensis MR-1 is quickly becoming a synthetic biology workhorse for bioelectrochemical technologies due to high level of understanding its interaction with electrodes. Transmembrane electron transfer via the Mtr pathway has been well characterized, however, role NADH dehydrogenases in feeding electrons only minimally studied S. MR-1. Four are encoded genome, suggesting significant metabolic flexibility oxidizing under variety conditions. A strain lacking two essential...

Bacteroides thetaiotaomicron is a prominent member of the human distal gut microbiota that specializes in breaking down diet and host-derived polysaccharides. While polysaccharide utilization has been well studied B. thetaiotaomicron, other aspects its behavior are less characterized, including factors allow it to maintain itself gut. Biofilm formation may be mechanism for bacterial retention Therefore, we used custom GeneChips compare transcriptomes biofilm planktonic during growth...

Shewanella oneidensis (S. oneidensis) is a model bacterial strain for studies of bioelectrochemical systems (BESs). It has two extracellular electron transfer pathways: 1) shuttling electrons via an excreted mediator riboflavin; and 2) direct contact between the c-type cytochromes at cell membrane electrode. Despite extensive use S. in such as microbial fuel cells biosensors, many basic microbiology questions about context BES remain unanswered. Here, we present motility chemotaxis under...

ABSTRACT Shewanella oneidensis MR-1 is a metal-reducing bacterium with the ability to utilize many different terminal electron acceptors, including oxygen and solid-metal oxides. Both metal oxide reduction aerobic respiration have been studied extensively in this organism. However, transport chain processes upstream of oxidoreductases relatively understudied organism, especially transfer from NADH respiratory quinones. Genome annotation indicates that S. encodes four dehydrogenases,...

Abstract Bacterial microcompartments (BMCs) are prokaryotic organelles that consist of a protein shell which sequesters metabolic reactions in its interior. While most the substrates and products relatively small can permeate shell, many encapsulated enzymes require cofactors must be regenerated inside. We have analyzed occurrence an enzyme previously assigned as cobalamin (vitamin B 12 ) reductase and, curiously, found it unrelated BMC types do not employ cofactors. propose NAD+...

Bacterial microcompartments (BMCs) are prokaryotic organelles that consist of a protein shell which sequesters metabolic reactions in its interior. While most the substrates and products relatively small can permeate shell, many encapsulated enzymes require cofactors must be regenerated inside. We have analyzed occurrence an enzyme previously assigned as cobalamin (vitamin B

Abstract Shewanella oneidensis MR‐1 is a promising chassis organism for microbial electrosynthesis because it has well‐defined biochemical pathway (the Mtr pathway) that can connect extracellular electrodes to respiratory electron carriers inside the cell. We previously found be used transfer electrons from cathode intracellular and drive reduction reactions. In this work, we hypothesized native NADH dehydrogenases form an essential link between in cytoplasm. To test hypothesis, compared...