Atmospheric-Pressure Plasma Jet Irradiation onto Main Components of the Cell Wall and Membrane of <i>Escherichia Coli </i>

Abstract

To clarify the mechanism underlying the inactivation of Escherichia coli (E. coli) cells subjected to atmosphericpressure argon (Ar) plasma jet irradiation, we focused on phospholipids, the main components of the cell wall and membrane of E. coli. Commercially available standard samples of phospholipids, phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) were irradiated with an atmospheric-pressure Ar plasma jet in air for 5 s. The phospholipids irradiated with the plasma jet were separated by thin-layer chromatography (TLC), and the results showed that PE was unchanged even after plasma jet irradiation, whereas PG was degraded into several substances. One of them was identified as lysophosphatidylglycerol (LPG), a lysophospholipid of PG, by liquid chromatography-mass spectrometry (LC-MS). From these results, we inferred that PG in the cell wall and membrane was degraded into LPG and a fatty acid by plasma jet irradiation, and that the cell wall and membrane were disrupted, inactivating E. coli.

Reduction in lateral lipid mobility of lipid bilayer membrane by atmospheric pressure plasma irradiation

“…24) Generally, the oxidation of phospholipids under physiological condition proceeds on its hydrocarbon chain with double bonds; but recently, Kuwahata et al reported a strong head-group dependence in the plasmainduced reaction of phospholipids. 65) The atmosphericpressure plasma irradiation of a dried film of a lipid extracted from Escherichia coli selectively breaks the ester bond of phosphatidylglycerol, producing lysophosphatidylglycerol, while phosphatidylethanolamine remains nearly unchanged. Further studies are needed to identify the species critical to the decrease in diffusion coefficient among the numerous candidates for plasma-induced ROS to clarify their mechanism of reaction with lipid molecules, and to determine the chemical structures of oxidatively modified phospholipids.…”

Structural Characterization of Neutral Glycosphingolipids from 3T3‐L1 Adipocytes

“…Semipurified samples dissolved in LC–MS-grade methanol were analyzed on LCMS-IT-TOF quadrupole ion trap time-of-flight mass spectrometer (Shimadzu, Japan) according to Kuwahata et al . [ 18 ].…”