Alkyl substituent effect on photosensitized inactivation of Escherichia coli by pyridinium-bonded P-porphyrins.

Activity of singlet oxygen sensitizers for photoinactivation of bacteria and photodynamic therapy of tumor cells has been evaluated using nonpathogenic model cells, such as Escherichia coli, Saccharomyces cerevisiae, and HeLa cells. Among them, E. coli, gram-negative bacterium, has complex membrane structures in the cell wall, resulting in an impermeable barrier to antimicrobial agents.