EFFECT OF STIRRER SPEED, AERATION RATE AND CELL MASS CONCENTRATION ONVOLUMETRIC OXYGEN-TRANSFER COEFFICIENTS (KLA) IN THE CULTIVATION OF CURVULARIA-LUNATA IN A BATCH REACTOR

Curvularia lunata was grown in a stirred and aerated reactor for the p roduction of extracellular rifamycin oxidase. Volumetric oxygen transf er coefficients (K(L)a) were measured for various stirrer speeds, rate s of aeration and cell mass concentrations in the reactor. Stirrer spe ed and aeration rate were optimized and it was found that stirrer spee ds of 400-500 rpm and aeration rates of 0.75-1 vvm were optimum for th e maximum amount of enzyme production. It was noticed that the increas e in cell mass decreased the oxygen transfer coefficient. It was also noticed that the organism formed pellets rather than mycelia when grow n on glucose and with an increase in the concentration of glucose in t he reactor, there was heavy pellet formation.