Table 6.
Influence of modifying P or dnaB on P lethality and plasmid loss.
| Host cells and plasmids | Cell viability a and (plasmid retention/cfu; %) b at growth temperature (˚C) | ||
|---|---|---|---|
| 25 | Ave 37 & 39 | 42 | |
| 594[pcIpR- P-timm] | 1.0 | 0.0049 | 0.001 |
| (195/196; ~100) | (0/57; 0) | (0/28; 0) | |
| 594[pcIpR- PSPA-timm] | 1.0 | 0.006 | 0.004 |
| (14/14; 100) | (0/150; 0) | (0/39; 0) | |
| 594[pcIpR- Pπ-timm] | 1.0 | 0.635 | 0.003 |
| (103/103; 100) | (789/793; ~100) | (0/294; 0) | |
| 594[pcIpR- PΔ76-timm] | 1.0 | 0.96 | 0.12 |
| (166/168; 99) | (334/336; 99) | (166/168; 99) | |
| 594 grpD55 [pcIpR-P-timm] | 1.0 | 0.99 | 1.0 |
| (35/35; 100) | (87/88; 99) | (14/14; 100) | |
| 594 grpD55 [pcIpR-PSPA-timm] | 1.0 | 0.75 | 0.57 |
| (42/42; 100) | (88/94; 94) | (18/19; 95) | |
| 594 grpD55 [pcIpR-Pπ-timm] | 1.0 | 0.08 | 0.01 |
| (54/54; 100) | (434/435; ~100) | (5/108; 5) | |
| 594 grpD55 [pcIpR-PΔ76-timm] | 1.0 (nd) | 0.45 (nd) | 0.001 (nd) |
| Re-claim pcIpR-P-timm from 594 grpD55 cultures and transform into 594 dnaB+ cells | |||
| Re-claim from 25˚C cultures c | 1.0 | 0.08 | 0.01 |
| (54/56; 96) | (0/119; 0) | (0/91; 0) | |
| Re-claim from 42˚C cultures d | 1.0 | 0.059 | 0.026 |
| (130/130; 96) | (1/230; 0.4) | (0/201; 0) | |
a : The cell viability shown in each column entry, in top line, was determined by dividing the cell titer obtained at each given incubation temperature by the cell titer at 25 ˚C.) Refer to Experimental Section 3.5.
b: The values in parentheses in each column entry show the number of AmpR cfu / number of survivor cfu assayed per indicated temperature; the value following represents the percentage of AmpR cfu with plasmids, and was rounded up. All data show the results for two or more independently transformed single colonies.
c : Exp.’s for sc1, sc2.
d : Exp.’s for sc’s 3,4,5, 6.