AbstractEnzyme production by immobilized Phanerochaete chrysosporium was evaluated in airlift bioreactor and agitated cultures. Free mycelium and immobilized mycelium on alginate beads were tested in the decolourization of 50 and 500 mg/L of Remazol Brilliant Blue R. Dye concentration did not inhibit the fungi development in all tests. In addition, high decolourization percentage of dye was found with free mycelium (99%) in agitated flasks and with immobilized mycelium in airlift (98%). However, decolourization period by immobilized mycelium (120 h) was greater than that by the free mycelium (14 h). Important manganese peroxidase, lignine peroxidase and laccase activities were identified in decolourization process. Manganese peroxidase appeared to be promoted by high dye concentrations during the treatment with immobilized mycelium, but this enzyme was not detected with free mycelium in airlift. Bioreactor prompted also laccase and lignine peroxidase actions in both tests; free mycelium registered a maximum laccase action of 31.569 × 103 U/L in 70 h, whereas immobilized mycelium registered 1.680 × 103 U/L in 170 h, while lignine peroxidase secretion by free P. chrysosporium was higher (1.300 × 103 U/L) than immobilized mycelium (1.250 × 103 U/L). Maximum laccase activity coincided with the maximum percentage of decolourization, however, high peroxidase activity was identified from the start of dye treatment.
Treatment of Recirculating Aquacultural Water by an Airlift Bioreactor Containing Immobilized Microorganisms
