Plant cell cultures can be used to alleviate the demands placed on harvest for the supply of important plant-derived products. Due to economic constraints, few plant cell culture processes are used commercially for the manufacture of such products. Limitations due to low volumetric productivity and variability in productivity can be overcome through a better understanding of cell culture heterogeneity. The objective of this project is to study the effects of plant cell heterogeneity on the production of valuable secondary metabolites. The research is focused on the anticancer agent paclitaxel, which can be produced from Taxus suspension cell cultures that are highly heterogeneous in terms of both metabolic and subpopulation variability. Baseline Taxus population information is being collected using multiparameter flow cytometry to characterize metabolic heterogeneity and to develop population balance equation models to correlate metabolic data with process scale information. Subpopulations based on paclitaxel accumulation (i.e., high, medium and low) will be collected using novel Fluorescence Activated Cell Sorting (FACS) techniques, and metabolic heterogeneity in the subpopulations will be characterized. The long-term stability of the sorted population will be analyzed in terms of growth and paclitaxel accumulation, and population balance equation models will be developed to predict population behavior. The results from this research will provide a detailed characterization of Taxus heterogeneity, which can then be used to design effective strategies to stabilize and optimize paclitaxel accumulation.
Funding: NSF (#073079)
Student: Martin Kolewe (3rd year Ph.D.)
Collaborator: Prof. Susan Roberts (UMass, primary advisor)
Publications: none