TY  - JOUR
AU  - Pajić-Lijaković, Ivana
AU  - Plavsić, Milenko
AU  - Bugarski, Branko
AU  - Nedović, Viktor
PY  - 2007
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/1494
AB  - A mathematical model was formulated to describe yeast cell growth within the Ca-alginate microbead during air-lift bioreactor cultivation. Model development was based on experimentally obtained data for the intra-bead cell concentration profile, after reached the equilibrium state, as well as, total yeast cell concentration per microbed and microbead volume as function of time. Relatively uniform cell concentration in the carrier matrix indicated that no internal nutrient diffusion limitations, but microenvironmental restriction, affected dominantly the dynamics of cell growth. Also interesting phenomenon of very different rates of cell number growth during cultivation is observed. After some critical time, the growth rate of cell colonies decreased drastically, but than suddenly increased again under all other experimental condition been the same. It is interpreted as disintegration of gel network and opening new free space for growth of cell clusters. These complex phenomena are modeled using the thermodynamical, free energy formalism. The particular form of free energy functional is proposed to describe various kinds of interactions, which affected the dynamics of cell growth and cause pseudo-phase transition of hydrogel. The good agreement of experimentally obtained data and model predictions are obtained. In that way the model provides both, the quantitative tools for further technological optimization of the process and deeper insight into dynamics of cell growth mechanism.
PB  - Elsevier, Amsterdam
T2  - Journal of Biotechnology
T1  - Ca-alginate hydrogel mechanical transformations - The influence on yeast cell growth dynamics
EP  - 452
IS  - 3
SP  - 446
VL  - 129
DO  - 10.1016/j.jbiotec.2007.01.017
ER  - 

@article{
author = "Pajić-Lijaković, Ivana and Plavsić, Milenko and Bugarski, Branko and Nedović, Viktor",
year = "2007",
abstract = "A mathematical model was formulated to describe yeast cell growth within the Ca-alginate microbead during air-lift bioreactor cultivation. Model development was based on experimentally obtained data for the intra-bead cell concentration profile, after reached the equilibrium state, as well as, total yeast cell concentration per microbed and microbead volume as function of time. Relatively uniform cell concentration in the carrier matrix indicated that no internal nutrient diffusion limitations, but microenvironmental restriction, affected dominantly the dynamics of cell growth. Also interesting phenomenon of very different rates of cell number growth during cultivation is observed. After some critical time, the growth rate of cell colonies decreased drastically, but than suddenly increased again under all other experimental condition been the same. It is interpreted as disintegration of gel network and opening new free space for growth of cell clusters. These complex phenomena are modeled using the thermodynamical, free energy formalism. The particular form of free energy functional is proposed to describe various kinds of interactions, which affected the dynamics of cell growth and cause pseudo-phase transition of hydrogel. The good agreement of experimentally obtained data and model predictions are obtained. In that way the model provides both, the quantitative tools for further technological optimization of the process and deeper insight into dynamics of cell growth mechanism.",
publisher = "Elsevier, Amsterdam",
journal = "Journal of Biotechnology",
title = "Ca-alginate hydrogel mechanical transformations - The influence on yeast cell growth dynamics",
pages = "452-446",
number = "3",
volume = "129",
doi = "10.1016/j.jbiotec.2007.01.017"
}

Pajić-Lijaković, I., Plavsić, M., Bugarski, B.,& Nedović, V.. (2007). Ca-alginate hydrogel mechanical transformations - The influence on yeast cell growth dynamics. in Journal of Biotechnology
Elsevier, Amsterdam., 129(3), 446-452.
https://doi.org/10.1016/j.jbiotec.2007.01.017

Pajić-Lijaković I, Plavsić M, Bugarski B, Nedović V. Ca-alginate hydrogel mechanical transformations - The influence on yeast cell growth dynamics. in Journal of Biotechnology. 2007;129(3):446-452.
doi:10.1016/j.jbiotec.2007.01.017 .

Pajić-Lijaković, Ivana, Plavsić, Milenko, Bugarski, Branko, Nedović, Viktor, "Ca-alginate hydrogel mechanical transformations - The influence on yeast cell growth dynamics" in Journal of Biotechnology, 129, no. 3 (2007):446-452,
https://doi.org/10.1016/j.jbiotec.2007.01.017 . .

TY  - JOUR
AU  - Pajić-Lijaković, Ivana
AU  - Plavsić, Milenko
AU  - Nedović, Viktor
AU  - Bugarski, Branko
PY  - 2007
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/1489
AB  - The rheological model is developed to elucidate the mechanism of Ca-alginate microbead deformation in the course of cell growth within. It is a complex process influenced by relaxation of the expanded polymer network inside a bead, and forces generated by cell growth inside the bead and interactions between solvent, network parts and cells as well. The resulting effects are measured experimentally by estimating isotropic volumetric deformations of beads with yeast cells as function of time and cell concentration per bead. The mathematical model of the process is developed based on a modified general Zener model with fractional derivatives. It is particularly suitable for incorporating effects of different nature also during different stages of such complex process development. The results of theoretical analyses using the model developed and comparison with experimental values obtained, indicate a high impact of partial decomposition, i.e. plastic response of polymer network inside a bead due to cell growth, on bead deformation. For comparison, corresponding deformation measurements and modelling were performed on the same network system exposed to swelling in the solvent, but without the cells. In this case elastic forces are dominant, indicating different mechanism of relaxation without the influence of cells, in agreement with previous conclusions.
PB  - Taylor & Francis Ltd, Abingdon
T2  - Journal of Microencapsulation
T1  - Investigation of Ca-alginate hydrogel rheological behaviour in conjunction with immobilized yeast cell growth dynamics
EP  - 429
IS  - 5
SP  - 420
VL  - 24
DO  - 10.1080/02652040701362843
ER  - 

@article{
author = "Pajić-Lijaković, Ivana and Plavsić, Milenko and Nedović, Viktor and Bugarski, Branko",
year = "2007",
abstract = "The rheological model is developed to elucidate the mechanism of Ca-alginate microbead deformation in the course of cell growth within. It is a complex process influenced by relaxation of the expanded polymer network inside a bead, and forces generated by cell growth inside the bead and interactions between solvent, network parts and cells as well. The resulting effects are measured experimentally by estimating isotropic volumetric deformations of beads with yeast cells as function of time and cell concentration per bead. The mathematical model of the process is developed based on a modified general Zener model with fractional derivatives. It is particularly suitable for incorporating effects of different nature also during different stages of such complex process development. The results of theoretical analyses using the model developed and comparison with experimental values obtained, indicate a high impact of partial decomposition, i.e. plastic response of polymer network inside a bead due to cell growth, on bead deformation. For comparison, corresponding deformation measurements and modelling were performed on the same network system exposed to swelling in the solvent, but without the cells. In this case elastic forces are dominant, indicating different mechanism of relaxation without the influence of cells, in agreement with previous conclusions.",
publisher = "Taylor & Francis Ltd, Abingdon",
journal = "Journal of Microencapsulation",
title = "Investigation of Ca-alginate hydrogel rheological behaviour in conjunction with immobilized yeast cell growth dynamics",
pages = "429-420",
number = "5",
volume = "24",
doi = "10.1080/02652040701362843"
}

Pajić-Lijaković, I., Plavsić, M., Nedović, V.,& Bugarski, B.. (2007). Investigation of Ca-alginate hydrogel rheological behaviour in conjunction with immobilized yeast cell growth dynamics. in Journal of Microencapsulation
Taylor & Francis Ltd, Abingdon., 24(5), 420-429.
https://doi.org/10.1080/02652040701362843

Pajić-Lijaković I, Plavsić M, Nedović V, Bugarski B. Investigation of Ca-alginate hydrogel rheological behaviour in conjunction with immobilized yeast cell growth dynamics. in Journal of Microencapsulation. 2007;24(5):420-429.
doi:10.1080/02652040701362843 .

Pajić-Lijaković, Ivana, Plavsić, Milenko, Nedović, Viktor, Bugarski, Branko, "Investigation of Ca-alginate hydrogel rheological behaviour in conjunction with immobilized yeast cell growth dynamics" in Journal of Microencapsulation, 24, no. 5 (2007):420-429,
https://doi.org/10.1080/02652040701362843 . .