Table 1. Lactate dehydrogenase activity.

Strain	μmol NADH/min (U)	U/mg
5GB1S	0.006 ± 0.0005	0.060 ± 0.005
5GB1S pLhldh uninduced	0.009 ± 0.0005	0.087 ± 0.005
5GB1S pLhldh aTc*	0.044 ± 0.006	0.435 ± 0.062
L. helveticus	0.025 ± 0.009	2.454 ± 0.891

^*LDH expression was induced with 0.5 μg/mL anhydrotetracycline (aTc) for 24 h. The data represent the mean ± SD of 3 independent observations.