Population balance approach to modeling hairy root growth.

Though numerous models have been developed to describe the growth of microbial cell cultures, far fewer models are available to describe the growth of hairy root cultures. Here a population balance model is proposed to simulate the growth of hairy roots. The model accounts for the increase in biomass due to elongation of a branch by cell division as well as the formation of new branches. The model incorporates the fact that although the likelihood of the formation of a new lateral branch is a maximum at a specific age of the parent branch, lateral branches can form over a distribution of ages of the parent branch. Model parameters are estimated using the genetic algorithm based on experimental data for batch and continuous bioreactors. The model proposed here may provide a better understanding of the increase in biomass of hairy root cultures.