ACA微囊化微生物细胞生长过程的数学模拟

Cell microencapsulation is one of the promising biotechnological processes for immobilized cell culture. In this work, E. coli and S. cerevisiae cells were immobilized and cultured in alginate-chitosan-alginate (ACA) microcapsule. The behavior of immobilized and free E. coli and S. cerevisiae cells in culture were studied and simulated by mathematical modeling. The Gompertz function and Richards function were modified and compared to describe the growth and metabolic process of immobilized and free microbial cells in culture for a better understanding of the growth process and its optimization. Both of the modified Gompertz and Richards model could be used to describe the growth and metabolic process in ACA encapsulated culture as well as in non-encapsulated free culture. Particularly, the modified Richards model was more suitable in describing the consumption of the controlling substrate due to the additional parameter, m. The experimental date and the models highlighted that ACA microcapsule immobilized culture could reach a higher maximum biomass concentration and a higher maximum biomass growth rate than in free microbial culture. It is indicated that the ACA microcapsule could be used in immobilized microorganism culture, which offered favorable microenvironment for cell growth. The effects of different status of ACA microcapsule cores on the cell growth and metabolism were further investigated. There was no significant difference in the growth and metabolism of microencapsulated cells whether the cores of the microcapsules were solid or liquefied respectively