PRODUCTION OF MANGANESE PEROXIDASE BY FREE PELLETS OF PHANEROCHAETE-CHRYSOSPORIUM IN AN EXPANDED-BED BIOREACTOR

Continuous production of Manganese Peroxidase by free pellets of Phane rochaete chrysosporium in an Expanded-Bed Bioreactor was successfully achieved for more than 30 days of operation. The stability in continuo us production was attained because of two modifications in the operati onal policy: an adequate feed control and the supply of oxygen in a pu lsing mode. Feed control allowed to stablish an equilibrium between pr imary and secondary metabolism, thus avoiding metabolic stress. The us e of pulsation had two beneficial effects: 1) Increase of stability by avoiding bed compactation during operation performance; 2) Control of mycelial pellet size. The bioreactor operated without oxygen pulsatio n did not maintain enzyme production longer than 14 days.