Abstract
The ATP pool and the cellular ATP level of a temperature-sensitive dnaK mutant were determined from the amount of total ATP measured by a modified ATP assay method, the number of viable cells, and dry cell weight. When the mutant cells at the mid-logarithmic phase were exposed to nonpermissive temperature, the initial levels of the ATP pool (5.07nmoles per mg dry cells) and cellular ATP (3.62nmoles per viable cell) remained nearly unchanged for over 3h. In the parental cells, however, both the ATP pool and the cellular ATP level decreased to one-third the initial levels. After 3h at permissive temperature, the ATP pool remained nearly unchanged but the cellular ATP level decreased to about 30 percent of the initial levels in both the mutant and parental strains. Our ATP assay method is quick and more easier; it is also reliable, because it provided values of the ATP pool that agree well with the values reported elsewhere.
