9522033 Curtis This proposal is on research to develop reactor design and operational principles for large-scale cultivation of root cultures for the production of biologically active chemicals such as pharmaceuticals, pesticides, and flavors. Preliminary studies have indicated that oxygen delivery is the fundamental design constraint for reactor scale-up.Therefore, the primary measures of reactor performance will be tissue respiration and biomass accumulation which are assessed by off-gas analysis and nutrient depletion correlations, respectively. Experiments will elucidate the role of gas dispersion, liquid mixing and diffusion of oxygen within the root tissue on reactor performance. Gas dispersion will be measured by argon tracer analysis/mass spectrometry, while liquid mixing will be assessed by dye tracers for both submerged and trickle-bed reactor operations. Also, oxygen diffusion within the root axis has been shown to limit respiration; therefore a study of root growth and respiration for a range of root species will be performed to experimentally validate a diffusionally controlled model for root biological oxygen demand. ***
