NUTRIENT REGULATION OF EXTRACELLULAR PEROXIDASES IN THE WHITE-ROT FUNGUS, BJERKANDERA SP STRAIN BOS55

Previous research indicated that the production of peroxidases in Bjer kandera sp. strain BOS55 increased under N-sufficient conditions. In t his study different organic N sources (amino acids, peptides, proteins ) were tested as N supplements. Most N sources significantly enhanced the titres of peroxidases, which increased in parallel with growth. Wh ile peroxidase production by Bjerkandera sp. strain BOS55 was not repr essed by the addition of sufficient or excess nitrogen, the occurrence of ligninolytic activity was a secondary metabolic event triggered by the cessation of growth. Among the factors studied (O-2, macronutrien ts, micronutrients, and vitamins), only those supplements with additio nal carbon or carbon and nitrogen increased the growth, indicating tha t the secondary metabolism was triggered by carbon limitation.