Table 2.

Expression of ackA-lacZ fusion inccpA mutantsa

StrainccpAalleleβ-Galactosidase activityRatio
− Glucose+ Glucose
BR151MACWTWild type441603.6
CPC18AV ccpA18AV281505.4
CPC48RC ccpA48RC321705.3
CPC286PL ccpA286PL271405.2
BR151MAccp::spc ccpA::spc 24271.1
  • a All strains contained anackA-lacZ transcriptional fusion (5). Cells were grown in TSS medium containing 1% Casamino Acids (− glucose) or TSS medium containing 1% Casamino Acids and 1% glucose (+ glucose). β-Galactosidase activities are expressed in Miller units (13) and indicate activity 30 min prior to the time of entry of the culture into stationary phase. The ratio indicates the level of induction during growth in the presence of glucose. All growth experiments were carried out at least twice, and samples were assayed in duplicate; variation was less than 10%.