Mechanism of photocatalytic bacterial inactivation on TiO2 films involving cell-wall damage and lysis

This article addresses the cell wall damage of Escherichia coli (from now on E. coli) by TiO2 suspensions. The dynamics of TiO2 photocatalysis by thin films layers is described. The films were characterized by FTIR spectroscopy and atomic force microscopy (AFM). The E. coli complete inactivation is shown to be due to the partial damage of the cell-wall components (peroxidation). A small increase in the cell wall disorder concomitant with a decrease of the cell wall functional groups leads to higher cell wall fluidity as the precursor step preceding cell lysis.

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► The damage of E. coli cell-wall bilayers on the TiO2 film was followed by FTIR.
► The FTIR with AFM and cell viability data shows that E. coli photocatalysis leads to lysis.
► A small amount of damage of the bilayer functional groups leads to increased wall fluidity and lysis.