The effects of adding manganese, 2,5-xylidine, veratryl alcohol and Tween 80 in a culture medium used for the production of ligninolytic enzymes by polyurethane foam-immobilized Ceriporiopsis subvermispora were studied. While 11 ppm Mn2+ promoted the highest maximum activity of manganese peroxidase (108.0 ± 43.3 U/L, in the 6th day of cultivation), the medium without manganese led to the highest maximum activity of laccase (15.5 ± 2.1 U/L, in the 12th day of cultivation). By supplementing the medium containing 11 ppm Mn2+ with 1.0 mM 2,5-xylidine, it was possible to improve the maximum activity of laccase to 21.5 ± 4.9 U/L. The supplementation of the medium containing 11 ppm Mn2+ with 1.0 mM veratryl alcohol, in turn, led to an apparent second peak of MnP activity (110.0 ± 1.4 U/L, in the 24th day of cultivation; compared to 147.5 ± 60.1 U/L, in the 9th day of cultivation). When the medium containing 11 ppm Mn2+ and 1.0 mM 2,5-xylidine was supplemented with 0.05% (v/v) Tween 80, the maximum activities of Lac and MnP reached 53.3 ± 17.7 U/L (21st day of cultivation) and 174.8 ± 1.4 U/L (9th day of cultivation), respectively. During the cultivations, the exhaustion of glucose in the medium promoted nutritional stress, which, in turn, led to cell autolysis; reflected by an apparent reduction in the concentration of mycelium, and by an increase in the concentration of ammonium. The concentrations of extracellular proteins increased throughout the cultivations; such concentrations, however, did not generally exhibit good correlations with the measured enzyme activities.
Key words: Ceriporiopsis subvermispora, manganese, 2,5-xylidine, veratryl alcohol, Tween 80; manganese peroxidase, laccase.
Lac, Laccase; MnP, manganese peroxidase; DNS, 3,5-dinitrosalicylic acid.
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