Role of Membrane Fluidity in Pressure Resistance of Escherichia coli NCTC 8164

作者：Maria Antonietta Casadei, Pilar Mañas, G. W. Niven, Eric C. Needs, Bernard M. Mackey · 发表于：Applied and Environmental Microbiology · 年份：2002 · DOI：10.1128/aem.68.12.5965-5972.2002 · 被引用次数：228 · 研究领域：Microbial Inactivation Methods、thermodynamics and calorimetric analyses、Viral gastroenteritis research and epidemiology

The relationship among growth temperature, membrane fatty acid composition, and pressure resistance was examined in Escherichia coli NCTC 8164. The pressure resistance of exponential-phase cells was maximal in cells grown at 10 degrees C and decreased with increasing growth temperatures up to 45 degrees C. By contrast, the pressure resistance of stationary-phase cells was lowest in cells grown at 10 degrees C and increased with increasing growth temperature, reaching a maximum at 30 to 37 degrees C before decreasing at 45 degrees C. The proportion of unsaturated fatty acids in the membrane lipids decreased with increasing growth temperature in both exponential- and stationary-phase cells and correlated closely with the melting point of the phospholipids extracted from whole cells examined by differential scanning calorimetry. Therefore, in exponential-phase cells, pressure resistance increased with greater membrane fluidity, whereas in stationary-phase cells, there was apparently no simple relationship between membrane fluidity and pressure resistance. When exponential-phase or stationary-phase cells were pressure treated at different temperatures, resistance in both cell types increased with increasing temperatures of pressurization (between 10 and 30 degrees C). Based on the above observations, we propose that membrane fluidity affects the pressure resistance of exponential- and stationary-phase cells in a similar way, but it is the dominant factor in exponential-phase cell...