Influence of Several Activators on the Extracellular Laccase Activity andIn vivo Decolourization of Poly R-478 by Semi-Solid-State Cultures ofTrametes versicolor

Abstract

The effect of several laccase activity activators,such as ethanol (novel activator), veratryl alcohol, melanin production and aeration level, on the laccase production by Trametes versicolor (CBS100.29) was investigated. The microorganism was cultivated on nylon sponge, functioning as a physical support on which the mycelium was bound. The cultures with veratryl alcohol showed maximum laccase and manganese-dependent peroxidase (MnP) activities of 238 U/l and 125 U/l, respectively. The laccase activity found is about two times higher than that attained in the control cultures. On the contrary, MnP activity did not appear to be influenced by the addition of this alcohol. Ethanol-supplemented cultures led to maximum laccase and MnP activity levels of about 102 U/l and 101 U/l, respectively. These activities were approx. 40% lower than those achieved in the reference cultures. The decolourization of the polymeric dye Poly R-478 by the above-mentioned cultures was also investigated. A percentage of biological decolourization of around 90% was achieved with control and veratryl alcohol-supplemented cultures, whereas with ethanol-supplemented cultures a slightly lower percentage of around 85% was reached after seven days of dye incubation.