TABLE 1.
Model | Equation | Conditions |
---|---|---|
Cell growth of Lactobacillus sakei CTC 494 | d[LAC]/dt = (μmax-LAC γi − Kd-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 -LISR − Kd−LISR) [LISR] | t ≥ λLISR |
Cell growth of the sensitive Listeria subpopulation | d[LISS]/dt = (μmax-LISS − Kd-LISS) [LISS] − ψ [B] [LISS] | t ≥ λLISS |
Bacteriocin activity | d[B]/dt = kBd[LAC]/dt − kinact [LAC] [B] | [LAC] ≥ [LACB] |
[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).