TABLE 3.
Glutamate AR of the different gad mutants
| Strain | Genotype | Adaptation mediuma | % Survival inb:
|
|
|---|---|---|---|---|
| Glutamate mediuma | Control mediuma | |||
| EK227 | Wild type | LBG | 71 | <0.005 |
| BHIG | 90 | <0.006 | ||
| EF491 | gadC::pRR10 | LBG | <0.008 | <0.005 |
| BHIG | <0.007 | <0.006 | ||
| EF493 | gadA::pRR10 | LBG | 42 | <0.006 |
| BHIG | 66 | <0.006 | ||
| EF507 | gadB::Km | LBG | <0.005 | <0.005 |
| BHIG | <0.006 | <0.007 | ||
| EF549 | gadB::Km/pGadC(Tc) | BHIGc | 52 | <0.004 |
| EF547 | gadC::pRR10/pGadC(Tc) | BHIGc | 30 | <0.004 |
| EF548 | gadA gadB/pGadC(Tc) | BHIGc | <0.005 | <0.005 |
a
Adaptation was carried out overnight either in LBG or in BHIG at 30°C. Acid challenge was performed by diluting 1:1,000 the overnight culture in EG at pH 2.5 with or without (control) 1.5 mM glutamate.
b
The percentage of survival was determined by measuring the number of surviving cells after 4 h of acid treatment.
c
Isopropyl-β-d-thiogalactopyranoside was added at 0.5 mM.