title: Kinetic analysis and mathematical modeling of growth and lactic acid production of Lactobacillus casei var. rhamnosus in milk whey.
abstract: Lactobacillus casei is a lactic acid bacterium (LAB) that colonizes diverse ecological niches and that has found broad commercial application. The aim of this study was to characterize the kinetics of biomass production, lactic acid production, and substrate consumption of Lactobacillus casei var. rhamnosus cultured in deproteinized milk whey. Batch culture experiments were performed in an instrumented, 2-L, stirred tank bioreactor using different inoculum concentrations (0.5 to 1.0 g/L) and lactose levels (35 to 70 g/L). The time series of experimental data corresponding to biomass growth, lactose consumption, and lactic acid formation were differentiated to calculate the corresponding kinetic rates. Strong exponentially dependent product inhibition effects were evident at low lactic acid concentrations, and lactic acid production rate was partially associated with biomass growth. A mathematical model is presented that reproduces the experimental lactose, biomass, and lactic acid concentration profiles.
authors.affiliation: Centro de Biotecnologia-FEMSA, Tecnológico de Monterrey, Ave. Eugenio Garza Sada, 2501 sur Monterrey, NL, México. Mario.alvarez@itesm.mx
authors.forename: M M
authors.initials: MM
authors.lastname: Alvarez
authors.forename: E J
authors.initials: EJ
authors.lastname: Aguirre-Ezkauriatza
authors.forename: A
authors.initials: A
authors.lastname: Ramírez-Medrano
authors.forename: A
authors.initials: A
authors.lastname: Rodríguez-Sánchez
mesh_terms: D000818:Animals; D018533:Biomass; D019149:Bioreactors; D003470:Culture Media / Q000378:metabolism; D007700:Kinetics; D019344:Lactic Acid / Q000096:biosynthesis*; D007780:Lacticaseibacillus casei / Q000254:growth & development* / Q000378:metabolism*; D007785:Lactose / Q000032:analysis; D008892:Milk / Q000737:chemistry / Q000382:microbiology*; D008894:Milk Proteins; D008954:Models, Biological; D000067816:Whey Proteins
chemical_list: D003470:Culture Media; D008894:Milk Proteins; D000067816:Whey Proteins; D019344:Lactic Acid; D007785:Lactose