Yeast surface display of dehydrogenases in microbial fuel-cells.

Two dehydrogenases, cellobiose dehydrogenase from Corynascus thermophilus and pyranose dehydrogenase from Agaricus meleagris, were displayed for the first time on the surface of Saccharomyces cerevisiae using the yeast surface display system. Surface displayed dehydrogenases were used in a microbial fuel cell and generated high power outputs. Surface displayed cellobiose dehydrogenase has demonstrated a midpoint potential of -28mV (vs.

Measuring localized redox enzyme electron transfer in a live cell with conducting atomic force microscopy.

Bacterial systems are being extensively studied and modified for energy, sensors, and industrial chemistry; yet, their molecular scale structure and activity are poorly understood. Designing efficient bioengineered bacteria requires cellular understanding of enzyme expression and activity. An atomic force microscope (AFM) was modified to detect and analyze the activity of redox active enzymes expressed on the surface of E.

Surface display of a redox enzyme and its site-specific wiring to gold electrodes.

The generation of a current through interaction between bacteria and electrodes has been explored by various methods. We demonstrate the attachment of living bacteria through a surface displayed redox enzyme, alcohol dehydrogenase II. The unnatural amino acid para-azido-L-phenylalanine was incorporated into a specific site of the displayed enzyme, facilitating electron transfer between the enzyme and an electrode.

In Situ fuel processing in a microbial fuel cell.

A microbial fuel cell (MFC) was designed in which fuel is generated in the cell by the enzyme glucoamylase, which is displayed on the surface of yeast. The enzyme digests starch specifically into monomeric glucose units and as a consequence enables further glucose oxidation by microorganisms present in the MFC anode. The oxidative enzyme glucose oxidase was coupled to the glucoamylase digestive enzyme.

Immobilization strategies of Brucella particles on optical fibers for use in chemiluminescence immunosensors.

Immunosensors are powerful analytical tools in clinical and veterinary diagnostics. This has led us to design a chemiluminescent immunosensor aimed at identifying anti-Brucella antibodies using optical fibers as the transducer. In order to develop the optimal transducer, to achieve an optimal chemical modification thereby allowing an optimal covalent binding of the protein receptor, several cleaning strategies and silane coupling agents were investigated.

Surface display of redox enzymes in microbial fuel cells.

A novel concept for a biofuel cell is presented. Enzyme based fuel cells suffer from enzyme instability when a long time of operation is required. Hence, a system that will continuously produce the biocatalyst needed for the system is necessary.

Biofuel cell controlled by enzyme logic systems.

An enzyme-based biofuel cell with a pH-switchable oxygen electrode, controlled by enzyme logic operations processing in situ biochemical input signals, has been developed. Two Boolean logic gates (AND/OR) were assembled from enzyme systems to process biochemical signals and to convert them logically into pH-changes of the solution. The cathode used in the biofuel cell was modified with a polymer-brush functionalized with Os-complex redox species operating as relay units to mediate electron transport between the conductive support and soluble laccase biocatalyzing oxygen reduction.