Temperature relationships in Mycobacterium kansasii: correlation between heat inactivation of protein synthesis and thermal death.

The temperature relationships of Mycobacterium kansasii were investigated. The optimal temperature of growth of these bacteria was between 37 and 38 degrees C, and their thermal death point was about 70 degrees. The temperature characteristic of growth of M. kansasii was about 23,400 cal.mole-1. Experiments on the effect of temperature on protein synthesis showed that the temperature and time relationships required to complete and irreversibly inactivate protein synthesis correlated with thermal death. Judged from the data obtained, it was hypothesized that the initial cause of thermal death in the bacteria might be the heat inactivation of the protein synthetic machinery of the cells.