Effect of Permeate Flux Rate on Alkaloid Production in a Novel Plant Cell Membrane Reactor Using Coffea arabica Cells

A novel membrane reactor was developed for phytochemical production using plant cells. The membrane reactor was a flat plate construction. An autoclavable, polypropylene membrane sheet with pore size 0.075 μm. was used. The membrane was surfactant treated by the manufacturer. Medium was recirculated through medium channels under the membrane. Cells were supplied with nutrients by permeated medium and obtained oxygen from the surrounding gas phase. In this work, the effect of permeate flux rate on cell growth, glucose uptake, and alkaloid production was examined. An arbitrary pressure index scale was developed to regulate the amount of medium that permeated the membrane. It was based on differential pressures between the cell chamber and the medium recirculation loop. These pressures were measured at the medium inflow and outflow points to the membrane reactor. Three 21‐day batch runs were carried out with the membrane reactor at pressure indices 38, 53, and 68 and compared to parallel shake‐flask runs. The pressure index 53 run was determined to be optimum for cell growth and purine alkaloid formation. Cell mass increase in the membrane reactor was 3.2‐fold and in parallel suspension cultures was 3.3‐fold, approximately 1.5 times that of the other two reactor runs. Glucose decreased linearly in the pressure index 53 membrane reactor run to 7.7 g/L, while glucose was completely consumed in the suspension cultures after 12 days. Final alkaloid concentration was 46.1 mg/L for the pressure index 53 membrane reactor run, approximately 2 times that of the other two membrane reactor runs and the suspension cultures.