TABLE 3.

Effect of peptidoglycan recycling on expression of nagB^a

Strain	Description	Glycerol		GlcN
		nagB-lacZ (U)	DT (min)	nagB-lacZ (U)	DT (min)
MC-B1	wt	69 ± 5	68 ± 5	229 ± 25	101 ± 4
MC-B196/7	nagK murQ anmK nagZ ampG nagE	61 ± 4	64 ± 5	119 ± 19	110 ± 3

^aβ-Galactosidase activities (Miller units) were measured in minimal MOPS medium with 0.2% glycerol or 0.2% GlcN at 37°C. MC-B1 is MC4100 with a nagB-lacZ fusion on a λ lysogen. MC-B196/7 is MC-B1 into which mutations nagK, murQ, anmK, nagZ, ampG, and nagE have been sequentially introduced to reduce recycling of peptidoglycan and formation of intracellular GlcNAc6P. DT (min) were calculated by linear regression between A₆₅₀ values of 0.08 to 0.8. Results are the means of four independent cultures.