Determinación de los parámetros cinéticos en la fermentación ácido-láctica mediante un enfoque termodinámico. Caso de estudio: Lactobacillus delbrueckii

Abstract

The maximum growth rate ( ), the substrate affinity constant ( ) and the constant of inhibition by product ( ) of Lactobacillus delbrueckii in lactic acid fermentation were determined by means of a mathematical model with a thermodynamic approach. The model was developed for a fermentation process considering the glucose as the carbon source, two operating temperatures (37 °C and 45 °C) and initial pH of 6.5 were employed. First, the values of were determined based on the mathematical model proposed by Heijnen for the two metabolic pathways that Lactobacillus delbrueckii can follow under anaerobic conditions and saturation of substrate. Subsequently, a model with a thermodynamic approach based on the concept of pseudo states of reaction was built to establish the values of for glucose concentrations lower than 1 M. The profiles of vs concentration of glucose were determined and linearized with kinetic not structured models by limitation of substrate in order to obtain the value of . In the same way, the value of through unstructured models by inhibiting by product. Finally, the achieved values of , and were compared with experimental values reported on bibliography resources.