Damaging effect of pressurized CO_2 on cell membrane of Escherichia coli

[Objective]The damage in the cell membrane of bacteria could be reflected on the leakiness of the material in bacteria and the absorption of dye in bacteria.Compared with pasteurization(63 °C,30 min),the damaging effect of pressurized CO2 on the cell membrane of Escherichia coli was studied.The aim of the study was to analyze the relationship between the death of Escherichia coli and the damage of cell membrane.[Methods]The change of cell membrane permeability and the leakiness of protein and nucleic acid in Escherichia coli were detected.The change of Escherichia coli morphology was observed by TEM.[Results]The results indicated that pressurized CO2 treatment induced the change of cell membrane permeability of Escherichia coli.Pressurized CO2 treatment induced the leakiness of protein in Escherichia coli,but the time of leakiness was lagged behind the time of 99% Escherichia coli death,so it was not the reason for death,it was only the secondary phenomenon of death.The death of Escherichia coli could be related to the leakiness of nucleic acid induced by the pressurized CO2 treatment.The death of Escherichia coli could be related to the ultrastructure change of Escherichia coli induced by the pressurized CO2 treatment.[Conclusion]There was direct relationship between the damaging effect of pressurized CO2 on cell membrane of Escherichia coli and the death of Escherichia coli.