TABLE 2.

Expression of dcuC′-′lacZ as a function of electron acceptors and C₄-dicarboxylates

Growth conditiona	dcuC′-′lacZ expression (β-galactosidase activity, in Miller units) of strain:
	IMW240 (wild type)	IMW255 (Δfnr)b	IMW256 (ΔarcA)b	IMW257 (narL::Tetr)b
Glucose	52	3	26	63
Glucosec + O2	4	3	6	NDd
Glucose + fumarate	99	3	42	87
Glucose + nitrate	38	ND	ND	51
Glucose + dimethyl sulfoxide	37	3	ND	ND
Glycerol + fumarate	109	NGe	ND	ND

^aM9 mineral medium supplemented with acid-hydrolyzed casein was used. Aerobic growth and anaerobic growth were carried out as described previously (1, 24). 

^bLike IMW240 (MC4100 with dcuC′-′lacZ) but with the indicated mutation. 

^cOr glycerol or succinate. 

^dND, not determined. 

^eNG, no growth.