Use of Phanerochaete chrysosporium Immobilized on Kissiris for Synthetic Dye Decolourization: Involvement of Manganese Peroxidase

The mineral Kissiris, which is formed from the thickened foam of volcanic lava, was tested to approximate its mineral composition using energy-dispersive X-ray (EDX) analysis. The solid mineral contains silicon dioxide at about 16 (w/w). The considerable surface roughness of Kissiris along with its extensive porosity made this natural solid cell support an attractive candidate for manganese peroxidase (MnP) production for synthetic dye decolourization, at low cost. The white rot fungus Phanerochaete chrysosporium immobilized on the mineral Kissiris was grown in both stationary and agitated cultures (rotary shaker, 100 rev/min) using either carbon- or nitrogen-limited growth medium to study the ability of the fungus to degrade the synthetic dye methylene blue (MB). The value of residual dye for MB used at 60 ppm was 6% within 8 days of the incubation of the nitrogen-limited culture under the shaken conditions. Production of (MnP) occurred simultaneously in nitrogen-limited culture medium with the added MnSO₄ at 100 ppm. The MnP activity was at relatively high level (170 U/l).