Production of catalase and glucose oxidase by Aspergillus niger using unconventional oxygenation of culture

A novel method for increasing dissolved oxygen concentration in culture med ia has been developed. It involves adding hydrogen peroxide (H2O2) to the m edium which is then decomposed to oxygen and water by catalase. Some factor s affecting oxygenation of culture were investigated. Maximal oxygen concen tration occurred in 50 ml of the medium containing 0.2 g wet myceliurn and 0.2% glucose at pH 5.0. A new apparatus for automated addition of H2O2 to t he bioreactor to keep the dissolved oxygen concentration constant over the range 1-100% +/- 2% was tested. A significant increase (over sixfold) of in tracellular catalase activity was obtained while the dissolved oxygen conce ntration remained stable (30% +/- 2%).