Influence of light on lignin-degrading activities of fungal genus Polyporus s. str.

Six strains belonging to five species of Polyporus (P. arcularius, P. arcularioides, P. tricholoma, P. cfr. tricholoma, and P. varius), collected from an Atlantic Forest area in Misiones (Argentina), where species usually grow exposed to high temperatures and humidity, were identified by morphological and molecular analyses. P. tricholoma (BAFC 4536) and P. arcularioides (BAFC 4534) were selected by their lignin degrading enzyme production, their ability to produce primordial of basidiomes under submerged fermentation, and the decrease in lignin content caused in Poplarwood (up to 29% after 45 days). Among several variables evaluated with a Plackett?Burman design (glucose, copper, vanillic acid and manganese concentration, incubation period, and light incidence), the most important factor affecting laccase and Mn peroxidase (MnP) production by both strains, was light incidence. Light induced fruit body development but diminished laccase and MnP production.Moreover, a modified isoenzymatic laccase pattern was observed, showing additional isoenzymes when fungi were cultivated under darkness and differences in optimal temperature. Although the studied strains did not produce high laccase and MnP titers (uppermost detected4230 and 90 U L−1, respectively), their laccases showed thermal stability and optimal temperature above 70 °C, representing an interesting source in the search of thermotolerant enzymes for biotechnological applications.

Fil: Grassi, Emanuel Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina. Instituto Misionero de Biodiversidad; Argentina

Fil: Robledo, Gerardo Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Fil: Levin, Laura Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina