Table 2 List of parameters used in the model
parameter | definition | value | reference/derivation |
|---|---|---|---|
K m·LP | Michaelis constant for lactose permease | 2.6 × 10-4 M | Patrick et al. (1997) [20] |
K cat·LP | rate constant for lactose transportation | 1.29 × 105h-1 | Patrick et al. (1997) |
K m·GAL | Michaelis constant for β-galactosidase | 9.8 × 10-4M | Moez et al. (2009) [25] |
K cat·GAL | hydrolysis rate for lactose | 1.65 × 105h-1 | Moez et al. (2009) |
K m·GLYC | Michaelis constant for glycolysis | 1 × 10-4M | L. Lactis Marcel et al. (2002) [26] |
V max·GLYC | maximum reaction speed when enzymes was saturated by substrate | 143.82M·h-1 | L. Lactis Marcel et al. (2002) |
K m·LDH | Michaelis constant for lactate dehydrogenase | 0.1 M | L. Lactis Marcel et al. (2002) |
V max·LDH | maximum reaction speed when lactate dehydrogenase was saturated by pyruvate | 307.08M·h-1 | L. Lactis Marcel et al. (2002) |
K LS | LacS synthesis rate constant | 564 h-1 | Kennell et al. (1977) [27] |
d LS | LacS decay rate constant | 0.6 h-1 | Kennell et al. (1977) |
K LZ | LacZ synthesis rate constant | 1.13 × 103h-1 | Kennell et al. (1977) |
d LZ | LacZ decay rate constant | 0.6 h-1 | Kennell et al. (1977) |
K LR | LacR synthesis rate constant | 564 h-1 | Assumed |
d LR | LacR decay rate constant | 0.6 h-1 | Assumed |
d M , d N | mRNA decay rate constant | 41.58 h-1 | Varmus et al. (1970) [28] and Patrick et. al. (1997) |
GR, G | lacR, lacSZ gene concentration | 2.5 × 10-9 M | Cheng et al. (2001) [29] |
n | steepness of the smooth switch function | 1 | Akyol et al. (2008) [15] |
K b | LacR/lactose binding rate constant | 7.2 × 104 M-1·h-1 | Assumed |
V 0 | basal rate of lacR gene transcription for mRNA | 1 h-1 | Assumed |
V 1 | increasing constant of lacR gene transcription for mRNA | 20 h-1 | Assumed |
V 2 | basal rate of lacSZ gene transcription for mRNA | 3.5 h-1 | Obtained by 'fitting' |
T max | maximum rate of lacSZ gene transcription | 6 × 104 h-1 | Assumed |
S | sensitivity of lacSZ gene transcription to LacS and LacZ | 1000 | Guessed |
K S | saturation constant for growth of L. bulgaricus on extracellular lactose | 9.82 × 10-3 M | Concepcion et al. (2000) [21] |
K LA | maximum lactic acid concentration to inhibit the growth of L. bulgaricus | 0.448 M | Concepcion et al. (2000) |
μ | maximum growth rate | 0.8 h-1 | Concepcion et al. (2000) |