Effect of oxygenation conditions on submerged cultures of Phanerochaete chrysosporium

Summary The effect of the oxygen supply pattern on the onset and development of the lignolytic enzyme system of Phanerochaete chrysosporium was studied in submerged culture employing the serum bottle approach. Periodic or continuous flushing through the head phase, and continuous bubbling through the liquid phase with either oxygen (O₂) or air were applied. The nature of the O₂ supply had a crucial regulatory effect not only on the formation of lignin-degrading peroxidases but also on their decay and on the production of extracellular protease activity and polysaccharides. Continuous oxygenation or aeration increased the glucose consumption rate, extracellular protease activity and polysaccharides. Gassing with air, whether continuous or periodic, sustained Mn-peroxidase activity while ligninase was undetectable. Continuous O₂ supply speeded up ligninase decay, displaying a sharper maximum, while a broader maximum and slower decay of ligninase activity were observed when supplying periodic O₂. Cultures initially grown with free exposure to air displayed a higher but sharper ligninase activity maximum when shifted to continuous rather than periodic O₂ supply. In general, the higher levels of either polysaccharides or protease activity corresponded to the lower levels and faster decay of ligninase and Mn-peroxidase activities.Offprint requests to: H. E. Grethlein