Influence of several activators on the extracellular laccase activity and in vivo decolourization of poly R-478 by semi-solid-state cultures of Trametes versicolor

The effect of several laccase activity activators, such as ethanol (novel a ctivator), veratryl alcohol, melanin production and aeration level, on the laccase production by Trametes versicolor (CBS 100.29) was investigated. Th e microorganism was cultivated on nylon sponge, functioning as a physical s upport on which the mycelium was bound. The cultures with veratryl alcohol showed maximum laccase and manganese-dep endent peroxidase (MnP) activities of 238 U/l and 125 U/l, respectively. Th e laccase activity found is about two times higher than that attained in th e control cultures. On the contrary, MnP activity did not appear to be infl uenced by the addition of this alcohol. Ethanol-supplemented cultures led to maximum laccase and MnP activity level s 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 c ultures, whereas with ethanol-supplemented cultures a slightly lower percen tage of around 85% was reached after seven days of dye incubation.