TABLE 2.

Expression of ackA-lacZ fusion in ccpA mutants^a

Strain	ccpA allele	β-Galactosidase activity		Ratio
		− Glucose	+ Glucose
BR151MACWT	Wild type	44	160	3.6
CPC18AV	ccpA18AV	28	150	5.4
CPC48RC	ccpA48RC	32	170	5.3
CPC286PL	ccpA286PL	27	140	5.2
BR151MAccp::spc	ccpA::spc	24	27	1.1

^aAll strains contained an ackA-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%.