Abstract
We designed the metal coating hollow fiber membrane as a new bactericidal material that may provide a novel simple water purification system. This membrane was coated with metal (Au) on the outer surface of the membrane. The membrane was able to remove bacteria from the bacteria suspension and bacteria trapped into the membrane could be killed by passing a DC 100mA through the membrane surface. To determine whether this bactericidal mechanism was mediated by the destruction of the cell wall on passing an electric current, intracellular components were measured in the aspirated solution. The destruction of the cell wall was confirmed because both intracellular components of nucleic acid and protein were clearly detected by passing an electric current. In general, bacteria are good electrical conductors to have negative charges on the surface of the cell wall. About ten percent of the electric resistance of the metal coating hollow fiber membrane decrease after bacteria were caught on the membrane surface. This decrement means the pass of an electric current through the cell body. On bacteria death, we speculate that the destruction of the cell wall occurs since passing an electric current through the cell body directly leads to the difficulty of the membrane resealing.
