[Relationship among growth temperature, membrane fatty acid composition and pressure resistance of Escherichia coli].
The relationship among growth temperature, membrane fatty acid composition and pressure resistance of Escherichia coli was studied. Results indicated that-the pressure resistance of exponential-phase cell was maximal in cell growth at 10 degrees C and decreased with increasing growth temperatures up to 45 degrees C. By contrast, the pressure resistance of stationary-phase cell was lowest in cell growth 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 cell and correlated closely with the melting point of the phospholipids extracted from whole cells. Therefore, pressure resistance in exponential-phase cell increased with greater membrane fluidity, whereas in stationary-phase cell, there was apparently no simple relationship between membrane fluidity and pressure resistance.
College of Food Science and Technology, Hunan Agriculture University, Changsha 410128, China. zongjunlee@yahoo.com.cn
Zong-jun
ZJ
Li
D002462:Cell Membrane / Q000737:chemistry*; D003470:Culture Media; D004926:Escherichia coli / Q000737:chemistry / Q000254:growth & development / Q000502:physiology*; D005227:Fatty Acids / Q000032:analysis*; D008560:Membrane Fluidity; D011312:Pressure; D013696:Temperature
D003470:Culture Media; D005227:Fatty Acids