Manganese peroxidase production by Bjerkandera sp BOS55 1. Regulation of enzymatic production

The white-rot fungus Bjerkandera sp. BOS55 has been suggested as a good alt ernative for the production of ligninolytic enzymes, specially Manganese pe roxidase (MnP), by its potential ability to degrade complex compounds. Howe ver, the application of this fungus requires the complete knowledge of the fermentation pattern in submerged cultures, conditions similar to those exi sting in industrial size reactors. For this purpose, the nutritional and en vironmental factors enabling high ligninolytic activity were studied. Accor ding to the results, under limitation and sufficiency of nitrogen, there is a threshold concentration for nitrogen from which MnP is produced. However , under nitrogen excess, the ligninolytic stage of the fungus was coinciden t with growth, with no apparent substrate limitation according to existing levels of carbon and nitrogen. Concerning carbon concentration, MnP synthes is took place independently of glucose concentration, this indicating that carbon limitation does not seem to be the triggering factor for MnP secreti on. Other two environmental factors were studied: oxygenation and agitation , but no significant effect on MnP production was observed, a quite differe nt aspect from the behaviour of other known fungi like Phanerochaete chryso sporium.