Decolouration of industrial metal-complex dyes in successive batches by active cultures of Trametes pubescens

The decolouration of the metal-complex dyes Bemaplex Navy M-T (150 mg/L) and Bezaktiv Blue BA (150 mg/L) in nine successive batches by immobilised cultures of the white-rot fungus Trametes pubescens was studied. Two different types of immobilisation supports were used: the commercial carriers Kaldnes™ K1 (synthetic supports) and sunflower-seed shells (SS) (natural supports). Bemaplex showed more resistance to degradation by T. pubescens cultures than Bezaktiv, especially in the K1 cultures. Thus, SS cultures led to decolouration percentages higher than 59% for Bemaplex in all the batches save for the last two and higher than 50% for Bezaktiv in all the batches except for the 2nd and 9th ones. K1 cultures showed decolouration percentages for Bemaplex higher than 42% in batches 1, 3, 4, 5 and 7 and for Bezaktiv higher than 70% in all the batches save for the last one. Dye decolouration was mainly due to enzyme action (biodegradation).