McKellar R C, Cholette H
Food Research Centre, Agriculture Canada, Ottawa.
Appl Environ Microbiol. 1987 Aug;53(8):1973-6. doi: 10.1128/aem.53.8.1973-1976.1987.
The influence of a shift in temperature from 20 to 32 degrees C on extracellular proteinase synthesis by Pseudomonas fluorescens B52 was examined. When cells actively synthesizing proteinase at 20 degrees C were shifted to 32 degrees C, enzyme synthesis ceased immediately. After 30 min at 32 degrees C, cells recovered at 20 degrees C after a lag of 30 min. Rifampin and chloramphenicol prevented recovery of synthesis at 20 degrees C. Rifampin-insensitive proteinase synthesis (an indirect measure of proteinase-specific mRNA pools) decreased after the exposure of cells to 32 degrees C for 30 min but was recovered during incubation at 20 degrees C. Controls not exposed to a temperature shift experienced no loss of rifampin-independent synthesis. Cells experienced a 50% reduction in mRNA pools after 15 min at 32 degrees C. The data support the working hypothesis that the loss of mRNA pools after treatment at 32 degrees C is responsible for the lag before the recovery of extracellular proteinase synthesis.
研究了温度从20摄氏度转变为32摄氏度对荧光假单胞菌B52胞外蛋白酶合成的影响。当在20摄氏度下积极合成蛋白酶的细胞转移到32摄氏度时，酶的合成立即停止。在32摄氏度下30分钟后，细胞在20摄氏度下经过30分钟的延迟后恢复。利福平和平氯霉素可阻止在20摄氏度下合成的恢复。细胞在32摄氏度下暴露30分钟后，利福平不敏感的蛋白酶合成（蛋白酶特异性mRNA池的间接测量）减少，但在20摄氏度下孵育期间恢复。未经历温度转变的对照未出现利福平非依赖性合成的损失。细胞在32摄氏度下15分钟后mRNA池减少了50%。数据支持这样的工作假设，即32摄氏度处理后mRNA池的损失是胞外蛋白酶合成恢复前延迟的原因。
