Table 3.

Glutamate AR of the different gad mutants

StrainGenotypeAdaptation mediuma% Survival inb:
Glutamate mediumaControl mediuma
EK227Wild typeLBG71<0.005
BHIG90<0.006
EF491gadC::pRR10LBG<0.008<0.005
BHIG<0.007<0.006
EF493gadA::pRR10LBG42<0.006
BHIG66<0.006
EF507gadB::KmLBG<0.005<0.005
BHIG<0.006<0.007
EF549gadB::Km/pGadC(Tc)BHIGc52<0.004
EF547gadC::pRR10/pGadC(Tc)BHIGc30<0.004
EF548gadA 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.