Growth rate of Escherichia coli at elevated temperatures: reversible inhibition of homoserine trans-succinylase.

The preceding paper (10) showed that the growth of Escherichia coli is slowed, without killing, at 40 to 45 C, and that in the several strains tested the cause is a decrease in the activity of homoserine trans-succinylase. These temperatures are now shown to inhibit the enzyme directly, in crude extracts and after partial purification. The effect is rapid and is immediately reversible, unlike the progressive and slowly reversible changes of conventional denaturation.