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. 2005 Nov;71(11):7567–7570. doi: 10.1128/AEM.71.11.7567-7570.2005

TABLE 1.

Equations used for model developmenta

Model Equation Conditions
Cell growth of Lactobacillus sakei CTC 494 d[LAC]/dt = (μmax-LAC γiKd-LAC) [LAC] t ≥ λLAC
γi = 1 [LAC] < [LAC1]
= 1 − I1 ([LAC] − [LAC1]) [LAC1] ≤ [LAC] ≤ [LAC2]
= (1 − I1 ([LAC2] − [LAC1]) − I2 ([LAC] − [LAC2]) [LAC] > [LAC2]
Cell growth of the resistant Listeria subpopulation d[LISR]/dt = (μmax -LISRKd−LISR) [LISR] t ≥ λLISR
Cell growth of the sensitive Listeria subpopulation d[LISS]/dt = (μmax-LISSKd-LISS) [LISS] − ψ [B] [LISS] t ≥ λLISS
Bacteriocin activity d[B]/dt = kBd[LAC]/dtkinact [LAC] [B] [LAC] ≥ [LACB]
a

[LAC] = cell concentration of Lactobacillus sakei CTC 494 (in CFU per ml), t = time (in hours), λ = lag phase (in hours), μmax = maximum specific growth rate (per hour), Kd = specific death rate (per hour), γi = self-inhibition function for Lactobacillus sakei CTC 494, [LAC1] and [LAC2] = critical cell concentrations (in CFU per ml) where the subscripts refer to inhibition phases, I1 and I2 = corresponding inhibition coefficients, [LIS]R = cell concentration of resistant Listeria innocua LMG 13568 (in CFU per ml), [LIS]S = cell concentration of sensitive Listeria innocua LMG 13568 (in CFU per ml), ψ = bacteriocidal coefficient (in ml hours per AU), [B] = bacteriocin activity (in arbitrary units ml−1), kB = specific bacteriocin production (in AU per CFU), kinact = apparent bacteriocin inactivation rate (in liters per CFU per hour), and [LACB] = minimum [LAC] for bacteriocin production, below which kB equals 0 (in CFU per ml).