| Abstract: | A fermentation system was designed and constructed to study the growth characteristics of microorganisms at low and high cell concentrations. The technique used to develop high cell densities utilized a rotating microfiltration unit to permit the removal of cell-free product from the fermenter. The fermenter volume and the filter were contained in a single unit composed of a series of concentric cylinders. Annuli contained the fermenter volume while the second outermost cylinder supported a microfiltration membrane. Feed to the system was pumped at constant rates, and the internal pressure built up to a value, which would effect the required filtration rate. The system was operated batchwise and continuously with and without filtration. The anaerobie growth characteristics of Streptococcus faccalus were determined at 37°C and pH 7.0 for batch, continuous, and continuous with filtration modes of operation. The growth characteristics were unchanged when the cell density was increased. Changes in cell yield peer model of glucose consumed were clearly illustrated during thee course of single run by operating the fermenter in the unsteady state with filtration. No consumption of glucose for developed was 40% packed cell volume, a value 45 times larger than could be grown in simple batch culture. |
