Laccase activity of Pycnoporus cinnabarinus grown in different culture systems

Abstract

Activity and zymogram patterns of laccases produced by Pycnoporus cinnabarinus (HEMIM-79) grown in three systems of submerged fermentation (airlift reactor, stirred tank reactor and Erlenmeyer flasks) and in solid-state fermentation using polyurethane foam as inert support, were studied. A culture medium based in glucose, yeast extract and mineral salts including copper sulfate as laccases inductor, was used in all grown systems. Very different activity levels were observed depending on the growth system and in all cases the zymogram patterns were similar. So, in this strain, the number of isoenzymes was independent of culture conditions but their amount changed, showing the highest values in the culture in shake flasks followed by the solid-state fermentation, followed by stirred tank reactor and the lowest activity was observed in airlift reactor. It is suggested that the difference in laccase activity could be due to the type of growth given in each system, the pellets by their small size are the metabolically more active compared to the big mass produced in the airlift reactor; although the stirred tank showed small pieces of mycelium, not showed an adequate growth by mechanical damage to cells. In the case of solid culture, the fungus growth was in mycelium form which is similar to its natural habitat.