TABLE 3.

Enzyme activity measurements

Strain	Carbohydrate in growth medium	Induction with galactosea	Activity ofb:
			Galactose-1-phosphate uridylyltransferase	β-Galactosidase	UDPgalactose 4-epimerase
NCDO2054	Glucose	No	—c	3.8 ± 0.2	788.5
	Lactose	No	225.9 ± 9.5	1,305.4 ± 122.6	8,735.2
	Galactose	No	350.2 ± 34.9	1,008.2 ± 80.5	7,801.1
	Glucose	Yes	178.8	441.5	NDd
LL144ΔgalT	Glucose	No	—	69.3 ± 5.1	ND
	Glucose	Yes	—	283.0	ND
LL139ΔlacZ	Glucose	No	—	—	ND
	Galactose	No	317.8 ± 37.9	—	ND

^aTo check for induction of enzyme activity, 20-ml cultures grown for 16 h in M17-glucose were washed and resuspended in 50 ml of fresh M17 broth containing 1% galactose and incubated at 30°C. Aliquots were removed after 3 h and assayed for galactose-1-phosphate uridyltransferase and β-galactosidase activities. 

^bIn nanomoles per minute per milligram of total protein. 

^c—, no measurable enzyme activity; i.e. <0.2 nmol per min per mg. 

^dND, not determined.