Modeling the Dynamics of Bacteriophage-host Interaction in Sauerkraut Fermentation
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The main objective of this study was to investigate the possibility of using starter cultures in sauerkraut fermentation and thereby reducing the quantity of salt used in the process. This in turn would reduce the amount of waste salt in our water resources. Phage, naturally present in sauerkraut fermentation, could potentially affect the starter cultures introduced. Thus, a mechanistic mathematical model was developed (using MATLAB) to quantify the growth kinetics of the phage and starter cultures. The model was validated based on the kinetics of Leuconostoc mesenteroides 1-A4, Leuconostoc pseudomesenteroides 3-B11 and their corresponding phage, Φ1-A4 and Φ3B-11, respectively, in MRS media. The predictions of the model were found to be in close agreement with experimentally determined phage and bacterial counts with time. Based on the results from the model, it was seen that phage quickly kills the host cells even when they are present in low numbers of the order of 10³ pfu/ml in the MRS media. A population of phage resistant cells was also found to be present, which replaced susceptible cells in the presence of phage. It was observed from the results of the model that the adsorption rate constant decreased with the time of phage-host interaction and was found to vary with initial cell densities. The effect of heterogeneity and other environmental factors such as temperature and pH should be considered to make the model applicable to commercial fermentations.
phage, fermentation, sauerkraut, mechanistic, Leuconostoc, modeling