SBIR Phase I: Novel Compact Cell Settler for Perfusion Cultures of Microbial Cells

The broader impact/commercial potential of this Small Business Innovative Research (SBIR) project is to reduce the manufacturing cost of therapeutic biologics using more efficient production technologies. This will be accomplished by developing novel cell retention technologies for increasing cell concentration and productivity in continuous perfusion bioreactor cultures of recombinant microbial and mammalian cells. Based on the inclined settler technology already proven in large scale mammalian cell cultures, compact and more efficiently scalable cell or particle settlers are being developed to expand its applications to other industrial areas, such as microbial yeast secretory production systems, heterogeneous catalysis, municipal water clarification, wastewater treatment, etc. Following thorough characterization of a novel compact cell settler device for recombinant microbial yeast cells during this Phase I grant, it will be launched commercially for large-scale manufacturing of biologics from recombinant microbial and mammalian cells. As biological manufacturing technology matures from early fed-batch cultures to continuous manufacturing due to increasing market size and more consistent product quality-by-design considerations, these novel compact settlers will enable more efficient production of many therapeutic biologics in large scale high cell density perfusion bioreactors and contribute to a significant reduction in cost of their manufacturing from recombinant mammalian and microbial cell cultures. This SBIR Phase I project proposes to develop a novel method of scaling up the proven inclined settler technology, which has been scaled up rectilinearly in the past as lamellar settlers. While the lamellar settlers have been used successfully to manufacture therapeutic biologics secreted by recombinant mammalian cells in high cell density perfusion bioreactors, they have not yet been adapted for microbial cell cultures. The research objectives of this proposal are to develop more compact and efficient settlers for recombinant yeast cells and characterize the capability of these settlers to remove dead cells selectively in the harvest and recycle the live and productive cells back to the bioreactors. Initial results from the first prototype demonstrate selective removal of the smaller yeast cells, while most of the larger cells are concentrated and recycled back to the bioreactor. Lower cell concentrations and smaller size distributions of the yeast cells leaving in the harvest stream from these compact settlers compared to the those in bioreactors will be measured in steady state continuous cultures and dramatically increasing cell density in the perfusion bioreactor due to the complete recycle of live and productive cells to bioreactor will be characterized for different perfusion harvest rates.