Modeling the cucumber fermentation: Growth ofLactobacillus plantarum

Summary Specific growth rate models of product-inhibited cell growth exist but are rarely applied to fermentations beyond ethanol and large-scale antibiotic production. The present paper summarizes experimental data and the development of a model for growth of the commercially important bacterium,Lactobacillus plantarum, in cucumber juice. The model provides an excellent correlation of data for the influence on bacterial growth rate of NaCl, protons (H⁺), and the neutral, inhibitory forms of acetic acid and the fermentation product, lactic acid. The effects of each of the variables are first modeled separately using established functional forms and then combined in the final model formulation.Nomenclature C] inhibitory component concentration, mM - C]_max concentration of the inhibitory component where the specific growth rate is zero, mM, determined by model fitting - H⁺] hydrogen ion concentration, mM - HLa] undissociated lactic acid concentration, mM - La^–] dissociated lactic acid concentration, mM - La_t] total lactic acid (HLa]+La^–]) concentration, mM - HAc] undissociated acetic acid concentration, mM - Ac^–] dissociated acetic acid concentration, mM - Ac_t] total acetic acid (HAc]+Ac^–]) concentration, mM - NaCl] sodium chloride concentration, %, w/v - specific growth rate, h^–1 - _max maximum specific growth rate, h^–1 - ₀ specific growth rate, h^–1, at 0 concentration of additive - K _ij inhibition coefficient - , ,K _m coefficients determined by model fitting Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the US Department of Agriculture or North Carolina Agricultural Research Service, nor does it imply approval to the exclusion of other products that may be suitable.