Extracellular phenoloxidase and peroxidase enzyme production during interspecific fungal interactions

Extracellular phenoloxidase enzymes have been implicated in the offensive/defensive strategies employed by fungi during interactions. To determine whether these enzymes are involved during Basidiomycete confrontations, a number of pairings between two brown-rot Basidiomycetes (Serpula lacrymans and Coniophora puteana) and several Deuteromycetes (Trichoderma spp. and Scytalidium FY) were performed. Laccase production was observed in pure cultures of C. puteana and Scytalidium FY, and in the interactions involving these two species. Laccase was also detected in the interactions involving S. lacrymans and all three Trichoderma isolates, although not in the respective pure cultures. Tyrosinase release was observed most frequently in interactions involving T. harzianum SIWT 25, although all other species also released tyrosinase under certain conditions, and peroxidase release was detected during all interspecific interactions. One exception involved T. viride SIWT 110 as this fungus did not produce tyrosinase under the experimental parameters utilized, and peroxidase release was inhibited during self-pairings and pairings involving the two other Trichoderma isolates. Extracellular laccase and tyrosinase production was much less on a low nutrient medium, although peroxidase production was not affected as strongly.