Evaluation of anamorphic state, wood decay and production of lignin-modifying enzymes for diatrypaceous fungi from Argentina

PILDAIN MARÍA BELÉN; NOVAS MARÍA VICTORIA; CARMARAN CECILICA CRISTINA

Journal of Agricultural Technology

KMITL Press

Lugar: Ladkrabang, Bangkok; Año: 2005 vol. 1 p. 81 - 96

1686-9141

Morphological descriptions, wood decay and anatomical criteria, production of ligninolytic and cellulolytic enzymes and melanin production of diatrypaceous species (Eutypella andicola, E. comosa, E. leprosa and E. scoparia) from Argentina were investigated. The anamorphic state of Eutypella andicola is described for the first time. The morphological characteristic of the anamorphs were similar among all strains. Most isolates were capable of causing mass loss in Populus deltoides wood blocks during a 12-week period. Differences among strains were significant. The anatomical observations demonstrated that in a first state of wood colonisation this fungi produced soft rot decay and in later colonisation state the decay type is similar to white rot. Extracellular production of ligninolytic and cellulolytic enzymes were studied by mycelium growing on solid medium supplemented with different dyes (Malachite green, Azure B, Poly R-478, Congo red, tannic and galic acid, and guayacol). Seven of the eight strains analysed decolourised all the dyes except for the Malachite green. Only one strain of E. scoparia was able to decolourise Malachite green. Through simple assays we established the production of “extracellular melanins” and its association to growth areas of the fungus and discoloration zones.