Adsorption and degradation of synthetic dyes on the mycelium of Trametes versicolor

Abstract

Adsorption and degradation of three synthetic dyes with representative chromophores (azo, anthraquinone and indigo) were investigated on living mycelium of white rot fungus, Trametes versicolor. The maximum adsorption capacity (Qmax) and adsorption affinity (K) of the dead and living fungal mycelia to the three dyes were measured and estimated by using the Langmuir model; Qmax has a range from 50 to 105 mg dye/g dry mycelium and K from 17 to 120 mg dye/L. The adsorbed dye molecules could be degraded by the extracellular and/or intracellular enzymes that were produced by a 10-day old fungal mycelium after the essential nitrogen nutrient (NH4+) had been consumed completely. Fungal mycelium was saturated by the dyes in one hour and its adsorption capacity was regenerated at different rates depending on dye structure and enzymes. Compared to the enzymatic regeneration of dye-saturated living mycelium (8-19 mg dye/g dry mycelium. h), physical desorption of adsorbed dye molecules was consistent ranging from 2-3 mg dye/g dry mycelium. h.