Physisporinus, a genus in Polyporales, Basidiomycota, is a versatile fungus that lives as a wood decomposer, a potential pathogen of standing trees, and an orchid mycobiont. We previously reported that some Physisporinus species inhabiting wet wood in aquatic environments such as streams and waterfalls form synnema-like structures (SSs) bearing acanthophyses at their apices, and that they produce acanthophyses on vegetative hyphae when cultured on agar media. In this study, we investigated the acanthophysis-forming ability in Physisporinus and allied genera, and experimentally demonstrated the function of SSs. Phylogenetic analyses and observations of Meripilus, Physisporinus and Rigidoporus cultures showed that all of the strains forming acanthophyses belonged to Physisporinus, whereas strains of Meripilus and Rigidoporus did not produce acanthophyses. These findings suggest that SS/acanthophysis formation is a useful taxonomic character for members of Physisporinus. When Physisporinus strains were cultured under oxygen (O₂) concentrations of 5, 10, 20 and 40%, most of those cultured under 20% O₂ formed the most acanthophyses. According to these experimental data, the SSs/acanthophyses in Physisporinus were considered to have a respiratory function. Physisporinus probably acquired the SS/acanthophysis-forming ability to adapt to moist and/or aquatic habitats and to decay wet wood in which the O₂ concentration is often low.

A powdery mildew was found on Leontopodium leontopodioides (Asteraceae) in China. Phylogenetic analyses using a combination of internal transcribed spacer and 28S rDNA sequences showed that this species, which clusters as sister to Neoerysiphe joerstadii, is allied to N. galii, N. geranii, and N. nevoi. This species differs from the closely allied N. joerstadii in the number and size of asci (3-10 asci, 55-75 × 20-40 µm versus 16-32 asci, 40-60 × 20-30 µm). This species is morphologically very similar to N. gnaphalii, but clearly differs from this species in having larger chasmothecia and colorless appendages. Therefore, the powdery mildew on L. leontopodioides is described as N. leontopodii sp. nov.

Edible basidiomycetes are highly active in the oxidative decomposition and polymerisation of polyphenols, and soybeans contain large amounts of isoflavones, which are polyphenol glycosides. Isoflavone aglycones exhibit weak estrogenic activities. In this study, we investigated the isoflavone content, polyphenol production, antioxidant activity and ergothioneine (EGT) content of soybeans fermented by Pleurotus cornucopiae and Pleurotus ostreatus. Isoflavone glycosides, which were abundant in unfermented soybeans, decreased, and aglycones increased on day 10 of culture in both edible basidiomycete-fermented soybeans. The total maximum polyphenol content in soybeans fermented by both mushrooms were approximately 4 times higher on day 30 to 40 of culture, than that of unfermented soybeans. P. cornucopiae-fermented soybeans showed maximum antioxidant activity on day 20 of culture, and this was approximately 6.1 times higher than that of unfermented soybeans. EGT was not detected in unfermented soybeans, whereas both fermented soybeans showed a maximum EGT content on day 20 of culture, which was especially high in P. cornucopiae-fermented soybeans. The antioxidant activity and EGT of P. cornucopiae-fermented soybeans were higher than those of P. ostreatus, suggesting that EGT was responsible for the increase in the antioxidant activity of P. cornucopiae-fermented soybeans.