Abstract: A gas sensor includes a biomaterial comprising electrically-conductive protein nanowires and at least two electrodes. The at least two electrodes are in operative arrangement with the protein nanowires and configured to provide a signal indicative of a change in conductivity of the protein nanowires. The conductivity of the protein nanowires is responsive to a change in concentration of a gas exposed to the biomaterial, such as ammonia, or to a change in relative humidity.

Abstract: Electrically conductive polymeric composite materials include microbially produced protein nanowires. The conductive composites are useful in diverse electronic materials applications, particularly in applications requiring biocompatibility, such as sensors and wearable electronics.

Abstract: The present invention provides, in various embodiments, electrically conductive protein nanowires (e-PNs) having surface exposed peptides that confer additional sensing capabilities and/or enhance binding to other materials, as well as fusion proteins and methods for making such nanowires. The present invention also provides sensor devices comprising the nanowires.

Abstract: A memristive device includes a biomaterial comprising protein nanowires and at least two electrodes in operative arrangement with the biomaterial such that an applied voltage induces conductance switching. An artificial neuron or an artificial synapse includes a memrisitive device with the electrodes configured to apply a pulsed voltage configured to mimic an action-potential input.

Abstract: The present invention provides, in various embodiments, genetically modified aerobic bacteria, polynucleotides and methods for expressing and/or harvesting electrically conductive protein nanowires (e-PNs). The present invention also provides e-PNs produced using the genetically modified aerobic bacteria, polynucleotides and methods.

Abstract: A gas sensor includes a biomaterial comprising electrically-conductive protein nanowires and at least two electrodes. The at least two electrodes are in operative arrangement with the protein nanowires and configured to provide a signal indicative of a change in conductivity of the protein nanowires. The conductivity of the protein nanowires is responsive to a change in concentration of a gas exposed to the biomaterial, such as ammonia, or to a change in relative humidity.

Abstract: A memristive device includes a biomaterial comprising protein nanowires and at least two electrodes in operative arrangement with the biomaterial such that an applied voltage induces conductance switching. An artificial neuron or an artificial synapse includes a memrisitive device with the electrodes configured to apply a pulsed voltage configured to mimic an action-potential input.

Abstract: Improved electrically conductive pili were generated from a natural pilus protein from the microorganism Geobacter sulfurreducens. Substituting a tryptophan for the phenylalanine at position F51 and a tryptophan for the tyrosine at position Y57 of the pilus monomer substantially increased the conductivity of the pili and reduced their diameter to 1.5 nm. Substantial improvements in conductivity were also achieved by substituting an additional tyrosine, histidine, and phenylalanine in the pilus monomer to mimic the monomer of Geobacter metallireducens, but the pili retained the typical Geobacter sulfurreducens wild-type diameter of 3 nm.

Abstract: A genetically engineered strain of Geobacter sulfurreducens exhibits improved function as a cathode biofilm compared to the wild type strain. The genetically engineered Geobacter sulfurreducens strain is capable of using carbon dioxide as a carbon source and electrical current as an energy source for producing a carbonaceous chemical using a reverse tricarboxylic acid pathway.

Abstract: A biosensor that employs a bacterium in a biofilm present on one of two electrodes of an electrochemical cell. The bacterium is genetically modified by having deleted at least one native gene that encodes for the enzymatic transformation of a molecular moiety, and having substituted for the deleted native gene a different gene having a transcription factor that is under the control of an inducible promoter in conjunction with an inducer molecule. When the molecular moiety is present in a specimen of interest that is in contact with the biofilm, an electric current is generated in response to the presence of the inducer molecule. In the absence of the inducer molecule, no electricity is generated. The electric signal that is generated can be analyzed to determine the presence and the quantity of the inducer molecule in the specimen of interest.

Abstract: The invention provides systems and methods for generating organic compounds using carbon dioxide as a source of carbon and electrical current as an energy source. In one embodiment, a reaction cell is provided having a cathode electrode and an anode electrode that are connected to a source of electrical power, and which are separated by a permeable membrane. A biological film is provided on the cathode. The biological film comprises a bacterium that can accept electrons and that can convert carbon dioxide to a carbon-bearing compound and water in a cathode half-reaction. At the anode, water is decomposed to free molecular oxygen and solvated protons in an anode half-reaction. The half-reactions are driven by the application of electrical current from an external source. Compounds that have been produced include acetate, butanol, 2-oxobutyrate, propanol, ethanol, and formate.

Abstract: A sensor that measures microbial activity as a surrogate value for the biologically active content of soil, aquatic sediments, or groundwater. An anode, such as a graphite anode that can support a biofilm, is connected by way of a resistor to a cathode. The anode is in contact with either soil, sediment, or immersed in the groundwater of a subsurface monitoring well. The biofilm generates electrons as a consequence of chemical interactions with materials such as acetate dissolved in the soil or sediment waters or groundwater. The cathode is located in soil or water adjacent to the ground, which can be aerobic, so that a reaction that consumes electrons occurs at the cathode. The current flowing through the resistor is a measure of the biological activity at the anode, which correlates with the flux of fuel such as acetate to the anode.

Abstract: The invention provides systems and methods for generating organic compounds using carbon dioxide as a source of carbon and electrical current as an energy source. In one embodiment, a reaction cell is provided having a cathode electrode and an anode electrode that are connected to a source of electrical power, and which are separated by a permeable membrane. A biological film is provided on the cathode. The biological film comprises a bacterium that can accept electrons and that can convert carbon dioxide to a carbon-bearing compound and water in a cathode half-reaction. At the anode, water is decomposed to free molecular oxygen and solvated protons in an anode half-reaction. The half-reactions are driven by the application of electrical current from an external source. Compounds that have been produced include acetate, butanol, 2-oxobutyrate, propanol, ethanol, and formate.

Abstract: In preferred embodiments, the present invention provides new isolated strains of a Geobacter species that are capable of using a carbon source that is selected from C3 to C12 organic compounds selected from pyruvate or metabolic precursors of pyruvate as an electron donor in metabolism and in subsequent energy production. The wild type strain of the microorganisms has been shown to be unable to use these C3 to C12 organic compounds as electron donors. The inventive strains of microorganisms are useful for improving bioremediation applications, including in situ bioremediation (including uranium bioremediation and halogenated solvent bioremediation), microbial fuel cells, power generation from small and large-scale waste facilities (e.g., biomass waste from dairy, agriculture, food processing, brewery, or vintner industries, etc.

Abstract: The invention provides systems and methods for generating organic compounds using carbon dioxide as a source of carbon and electrical current as an energy source. In one embodiment, a reaction cell is provided having a cathode electrode and an anode electrode that are connected to a source of electrical power, and which are separated by a permeable membrane. A biological film is provided on the cathode. The biological film comprises a bacterium that can accept electrons and that can convert carbon dioxide to a carbon-bearing compound and water in a cathode half-reaction. At the anode, water is decomposed to free molecular oxygen and solvated protons in an anode half-reaction. The half-reactions are driven by the application of electrical current from an external source. Compounds that have been produced include acetate, butanol, 2-oxobutyrate, propanol, ethanol, and formate.

Abstract: Embodiments of the present invention provide a method of producing genetically modified strains of electricigenic microbes that are specifically adapted for the production of electrical current in microbial fuel cells, as well as strains produced by such methods and fuel cells using such strains. In preferred embodiments, the present invention provides genetically modified strains of Geobacter sulfurreducens and methods of using such strains.

Abstract: In preferred embodiments, the present invention provides new isolated strains of a Geobacter species that are capable of using a carbon source that is selected from C3 to C12 organic compounds selected from pyruvate or metabolic precursors of pyruvate as an electron donor in metabolism and in subsequent energy production. The wild type strain of the microorganisms has been shown to be unable to use these C3 to C12 organic compounds as electron donors. The inventive strains of microorganisms are useful for improving bioremediation applications, including in situ bioremediation (including uranium bioremediation and halogenated solvent bioremediation), microbial fuel cells, power generation from small and large-scale waste facilities (e.g., biomass waste from dairy, agriculture, food processing, brewery, or vintner industries, etc.

Abstract: In preferred embodiments, the present invention provides new isolated strains of a Geobacter species that are capable of using a carbon source that is selected from C3 to C12 organic compounds selected from pyruvate or metabolic precursors of pyruvate as an electron donor in metabolism and in subsequent energy production. In other aspects, other preferred embodiments of the present invention include methods of making such strains and methods of using such strains. In general, the wild type strain of the microorganisms has been shown to be unable to use these C3 to C12 organic compounds as electron donors in metabolic steps such as the reduction of metallic ions. The inventive strains of microorganisms are useful for improving bioremediation applications, including in situ bioremediation (including uranium bioremediation and halogenated solvent bioremediation), microbial fuel cells, power generation from small and large-scale waste facilities (e.g.

Abstract: The invention provides systems and methods for generating organic compounds using carbon dioxide as a source of carbon and electrical current as an energy source. In one embodiment, a reaction cell is provided having a cathode electrode and an anode electrode that are connected to a source of electrical power, and which are separated by a permeable membrane. A biological film is provided on the cathode. The biological film comprises a bacterium that can accept electrons and that can convert carbon dioxide to a carbon-bearing compound and water in a cathode half-reaction. At the anode, water is decomposed to free molecular oxygen and solvated protons in an anode half-reaction. The half-reactions are driven by the application of electrical current from an external source. Compounds that have been produced include acetate, butanol, 2-oxobutyrate, proponal, ethanol, and formate.

Abstract: A microbial fuel cell is provided according to embodiments of the present invention including electricigenic microbes containing at least about 0.075 milligrams of protein per square centimeter of the anode surface area. In particular embodiments, the electricigenic microbes are disposed on the anode such that at least about 90% of the portion of the anode surface area has a layer of electricigenic microbes, the layer greater than about 1 micron in thickness. This thickness is indicative of the layer including at least a first stratum of electricigenic microbes in direct contact with the anode and a second stratum of electricigenic microbes in direct contact with the first stratum such that the second stratum is in indirect contact with the anode.