title: Modelling the biphasic growth and product formation by Enterococcus faecium CECT 410 in realkalized fed-batch fermentations in whey.
abstract: The influence of initial pH on growth and nutrient (total sugars, nitrogen, and phosphorous) consumption by Enterococcus faecium CECT 410 was studied during batch cultures in whey. With these data, two realkalized fed-batch fermentations were developed using different feeding substrates. The shift from homolactic to mixed acid fermentation, the biphasic kinetics observed for cell growth and nitrogen consumption and the increase in the concentrations of biomass and products (lactic acid, acetic acid, ethanol, and butane-2,3-diol) were the most noteworthy observations of these cultures. Modelling the fed-batch growth of Ent. faecium with the Logistic and bi-Logistic models was not satisfactory. However, biomass production was best mathematically described with the use of a double Monod model, which was expressed in terms of biomass, product accumulation, and nitrogen utilization. Product formation was successfully modelled with a modified form of the Luedeking and Piret model developed in this study.
authors.affiliation: Department of Analytical and Food Chemistry, Food Science and Technology Faculty, Ourense Campus, University of Vigo, 32004 Ourense, Spain. nelsonpg@uvigo.es
authors.forename: Nelson Pérez
authors.initials: NP
authors.lastname: Guerra
authors.forename: Paula
authors.initials: P
authors.lastname: Fajardo
authors.forename: Clara
authors.initials: C
authors.lastname: Fuciños
authors.forename: Isabel Rodríguez
authors.initials: IR
authors.lastname: Amado
authors.forename: Elisa
authors.initials: E
authors.lastname: Alonso
authors.forename: Ana
authors.initials: A
authors.lastname: Torrado
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Pastrana
mesh_terms: D019342:Acetic Acid / Q000378:metabolism; D000818:Animals; D019149:Bioreactors / Q000382:microbiology*; D002072:Butylene Glycols / Q000378:metabolism; D016984:Enterococcus faecium / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007785:Lactose / Q000378:metabolism; D016015:Logistic Models; D008892:Milk / Q000378:metabolism*; D008954:Models, Biological
chemical_list: D002072:Butylene Glycols; D000431:Ethanol; D007785:Lactose; D019342:Acetic Acid