Radiation and Microgravity are extreme space conditions where certain micro-organisms have been able to survive. These conditions can cause the up-regulation of radiation-induced DNA repair processes ..
Radiation and Microgravity are extreme space conditions where certain micro-organisms have been able to survive. These conditions can cause the up-regulation of radiation-induced DNA repair processes due to the production of reactive oxidative species (ROS) and reactive nitrogen species (RNS). The proposed project seeks to understand the changes in the electrophysiological properties, such as permittivity and conductivity of the cell membrane, on the internal components of the model bacteria E. coli K-12, by utilizing techniques known as impedance methods and Dielectrophoresis (DEP). The DEP force will be produced by an optimum Alternating current (AC) voltage and a given frequency passing through an interdigitated electrode. It is hypothesized that the combination of radiation and microgravity exposure to bacterial samples will show a change in the conductivity and permittivity of the cell membrane. Furthermore, the simulated radiation environment using microgravity and gamma radiators (cobalt-60 and cesium-127) will cause increased production of ROS and RNS species, resulting in the conductivity of the cell membrane’s internal components to increase. The increase in conductivity will cause a change in impedance and AC frequency, which can be quantitatively measured. Two methods of analysis are present: (1) fluorescent imaging of fluorescently tagged bacteria, and (2) correlation of the electrical measurement of impedance to produce the final result. For future experiments, it is planned to correlate the data collected with transcriptomic analysis of genes to understand the changes in these properties at the molecular level.