M Carla Groff1,2, Gustavo Scaglia3,4, Oscar A Ortiz4, Sandra E Noriega5. 1. Instituto de Investigaciones en Ciencias Químicas, Facultad de Ciencias Químicas y Tecnológicas, Universidad Católica de Cuyo, Av. Ignacio de la Roza 1516 Oeste, CP 5400, Rivadavia, San Juan, Argentina. mcarlagroff@gmail.com. 2. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Juan, Argentina. mcarlagroff@gmail.com. 3. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Juan, Argentina. 4. Instituto de Ingeniería Química, Universidad Nacional de San Juan, San Juan, Argentina. 5. Instituto de Investigaciones en Ciencias Químicas, Facultad de Ciencias Químicas y Tecnológicas, Universidad Católica de Cuyo, Av. Ignacio de la Roza 1516 Oeste, CP 5400, Rivadavia, San Juan, Argentina.
Abstract
OBJECTIVES: To obtain a mathematical model that adequately describes the time lag between biomass generation and lactic acid production of lactic fermentations. METHODS: Seven experimental kinetics from other research works were studied to validate our proposal: four studies of Fungal Submerged Fermentation and three cases of Bacterial Submerged Fermentation, including the data recollected by Luedeking and Piret. RESULTS: We introduce a modification to the Luedeking and Piret model that consist in the introduction of a time delay parameter in the model, this parameter would account for the lag time that exists between the production of biomass and lactic acid. It is possible to determine this time delay in a simple way by approximating the biomass and product formation considering that they behave as a first order plus dead time system. The duration of this phenomenon, which is not described with the classical Luedeking and Piret model, is a function of microorganism physiology (ease of biomass growth), environment (nutrients) and type of inoculum. CONCLUSION: The Luedeking and Piret with delay model applications reveal an increase of the R2 in all cases, evidencing the quality of fit and the simplicity of the method proposed. These model would improve the accuracy of bioprocess scaling up.
OBJECTIVES: To obtain a mathematical model that adequately describes the time lag between biomass generation and lactic acid production of lactic fermentations. METHODS: Seven experimental kinetics from other research works were studied to validate our proposal: four studies of Fungal Submerged Fermentation and three cases of Bacterial Submerged Fermentation, including the data recollected by Luedeking and Piret. RESULTS: We introduce a modification to the Luedeking and Piret model that consist in the introduction of a time delay parameter in the model, this parameter would account for the lag time that exists between the production of biomass and lactic acid. It is possible to determine this time delay in a simple way by approximating the biomass and product formation considering that they behave as a first order plus dead time system. The duration of this phenomenon, which is not described with the classical Luedeking and Piret model, is a function of microorganism physiology (ease of biomass growth), environment (nutrients) and type of inoculum. CONCLUSION: The Luedeking and Piret with delay model applications reveal an increase of the R2 in all cases, evidencing the quality of fit and the simplicity of the method proposed. These model would improve the accuracy of bioprocess scaling up.
Authors: Muhammad Naziz Saat; Mohamad Suffian Mohamad Annuar; Zazali Alias; Ling Tau Chuan; Yusuf Chisti Journal: Bioprocess Biosyst Eng Date: 2013-09-05 Impact factor: 3.210