Some species of Perenniporia Murrill (Poriales, Basidiomycotina) from Southern Brazil

Perenniporia contraria, P. martius, P. medulla-panis, P. ohiensis, P. piperis, P. stipitata and P. tephropora are described in this paper. A key to these species is presented. Five species studied in culture are included, through the respective species code. P. tephropora is a new record from Southern Brazil. A check-list of names Perenniporia species known throughout the world is given.

Lignocellulosic polysaccharides and lignin degradation by wood decay fungi: the relevance of nonenzymatic Fenton-based reactions

The brown rot fungus Wolfiporia cocos and the selective white rot fungus Perenniporia medulla-panis produce peptides and phenolate-derivative compounds as low molecular weight Fe(3+)-reductants. Phenolates were the major compounds with Fe(3+)-reducing activity in both fungi and displayed Fe(3+)-reducing activity at pH 2.0 and 4.5 in the absence and presence of oxalic acid. The chemical structures of these compounds were identified. Together with Fe(3+) and H(2)O(2) (mediated Fenton reaction) they produced oxygen radicals that oxidized lignocellulosic polysaccharides and lignin extensively in vitro under conditions similar to those found in vivo. These results indicate that, in addition to the extensively studied Gloeophyllum trabeum-a model brown rot fungus-other brown rot fungi as well as selective white rot fungi, possess the means to promote Fenton chemistry to degrade cellulose and hemicellulose, and to modify lignin. Moreover, new information is provided, particularly regarding how lignin is attacked, and either repolymerized or solubilized depending on the type of fungal attack, and suggests a new pathway for selective white rot degradation of wood. The importance of Fenton reactions mediated by phenolates operating separately or synergistically with carbohydrate-degrading enzymes in brown rot fungi, and lignin-modifying enzymes in white rot fungi is discussed. This research improves our understanding of natural processes in carbon cycling in the environment, which may enable the exploration of novel methods for bioconversion of lignocellulose in the production of biofuels or polymers, in addition to the development of new and better ways to protect wood from degradation by microorganisms.

Aportacion al conocimiento de los hongos del SE de EspaÑa. VIII. Afiloforales (Basidiomicetes)

Se da cuenta de 131 especies de Afiloforales para el S.E. español, se estudian 92 de ellas, indicando las localidades donde han sido registradas. 50 de estas especies son citas nuevas para la zona y de entre ellas: Antrodia ramentacea, A. sinuosa, Crustoderma dryinum, Ciphellopsis confusa, Heningsomyces púber, Hydnellum concrescens, Lachnella alboviolascens, Oxypoporus latemarginatus, Steccherinum ciliolatum y Stereum raméale son posiblemente nuevas para el catálogo español. Se describen además de éstas, las siguientes especies: Hyphodontia arguta, H. pruni, H. stipata, Perenniporia rosmaxini y Tyromices inocybe. Se incluye catálogo por orden alfabético de las 131 especies y se las relaciona con las 33 especies vasculares que actúan como substrato para ellas.