TABLE 2.

Specific activities of quinone-dependent l-lactate dehydrogenase and quinone-dependent d-lactate dehydrogenase in various C. glutamicum strains during growth on glucose or l-lactate

C. glutamicum strain	Sp act (μmol mg−1 · min−1) of the following enzyme during growth on the indicated substratea
	l-Lactate dehydrogenase (quinone dependent)		d-Lactate dehydrogenase (quinone dependent)
	Glucose	l-Lactate	Glucose	l-Lactate
ATCC 13032	0.03	0.23	0.13	0.19
ATCC 13032(pEKEx3)	0.03	0.20	0.11	0.25
ATCC 13032(pEKEx3-lldD)	1.41	0.99	0.09	0.15
13032::pK18mobNCgl2816int	0.02	NGb	0.14	NGc
13032::pK18mobNCgl2816int(pEKEx3)	0.02	NG	0.17	NG
13032::pK18mobNCgl2816int(pEKEx3-lldD)	0.58	0.63	0.09	0.15

^aNG, no growth occurred on l-lactate.

^bC. glutamicum 13032::pK18mobNCgl2816_int grown on a mixture of 100 mM l-lactate with 50 mM glucose showed a specific activity of quinone-dependent l-lactate dehydrogenase of 0.03 μmol mg⁻¹ · min⁻¹, while C. glutamicum ATCC 13032 showed 0.23 μmol mg⁻¹ · min⁻¹.

^cDuring growth on the l-lactate-glucose mixture, the specific activities of quinone-dependent d-lactate dehydrogenase were 0.15 μmol mg⁻¹ · min⁻¹ in

^legendC. glutamicum 13032::pK18mobNCgl2816_int and 0.20 μmol mg⁻¹ · min⁻¹ in C. glutamicum ATCC 13032.