TABLE 4.
Effect of cell density on viability of dnaE(Ts) strains incubated at 40°C
| dnaE allele | Length of incubation at 40°C (h) |
N/N0 at a culture dilution ofa:
|
|||
|---|---|---|---|---|---|
| 10−1 | 10−2 | 10−3 | 10−4 | ||
| dnaE+ | 5 | 4.9 | 22.7 | 96.6 | 386 |
| dnaE74 | 5 | 5.2 | 0.048 | 0.00078 | 0.00061 |
| dnaE486 | 4 | 1.08 | 0.0058 | 0.001 | |
a
N, viable count after incubation at 40°C; N0, viable count for nonincubated culture. Cultures were grown overnight at 27°C in LB medium. The cultures were then harvested, washed, resuspended in fresh LB medium, and diluted. Cultures were incubated with shaking at 40°C. The viable counts for nonincubated cultures were 8.8 × 109 cells/ml for the dnaE+ strain, 6.9 × 109 cells/ml for the dnaE74 strain, and 4.0 × 109 cells/ml for the dnaE486 strain.