| LDH | Microorganisms | |
| LD | cpLN | |
| Genes localization | Chromosomic genes [30] . | Chromosomic genes [31] . |
| Activating factors/ optimal activity parameters | Activators: fructose-1,6-diphosphate (FDP) (transcriptional and allosteric activation) and NADH [7] , Carbon source: glucose, lactoseSugar in excess [32] . | No activators found—no regulation found [3] [33] Optimal pH for Ln lactis: 7.5 [24] . |
| Inhibitory factors | Oxygen which is associated to a lower FDP concentration [32] , phosphoenolpyruvate (PEP) and inorganic phosphates [10] Sugar-limited conditions, high aerationLow NADH/NAD ratio (inferior to 0.03) and inorganic phosphate [34] . | pH inferior to 5 [33] . |
| Enzymes characteristicsa | Specific activity of 0.0043 U/mgMichaelis constant (Km) for pyruvate: 3 mM at pH 7.2 [34] . | For Ln lactis, the kinetic parameters decrease as the pH decreases: the Km for NADH, pyruvate, and the Vmax decrease 30-, 20- and 8-fold respectively as the pH decreases from 8 to 5 [33] For Ln lactis: Km for NADH are 0.307 and 0.023 mM at pH 7 and 5 respectivelyKm for pyruvate are 1.23 and 0.062 mM at pH 7 and 5 respectively [33] Km for pyruvate: 1.05, 0.25 and 0.13 mM at pH values of 7.5, 6.5 and 5.0 respectively [24] , The optimum pH decreases as the level of pyruvate decreases [33] . For Ln mesenteroides subsp. cremoris: Km for pyruvate: 0.3 mMKm for NADH: 0.03 mM [31] . |