Susanna Pecchia

A comparative study of Neogymnomyces virgineus, a new keratinolytic species from dung, and its relationships with the Onygenales

Isolations of onygenalean fungi were made recently from different dung samples from Italy. A striking snow-white species with gymnothecial ascomata, developed in damp chamber on dormouse dung collected in a cave, was subjected to keratinolytic tests and morphological, cultural, and phylogenetic studies. The keratinolytic ability of this species, associated with a Chrysosporium anamorph and a sexual state of appendiculate reticuloperidia and oblate ascospores, allows it to be accomodated in Onygenaceae. White ascomata, blunt or subcapitate peridial appendages, pitted ascospores, and tuberculate conidia suggest it to be a new Neogymnomyces, and this was confirmed by parsimony analyses of LSU and ITS nrDNA sequences. Following recent phylogenetic analyses, the morphological and physiological features of order Onygenales and its families are re–examined and discussed. After the introduction of a new species, Neogymnomyces is reviewed and compared with all other genera in Onygenaceae. The Chrysosporium imperfect state of Neogymnomyces virgineus is described and compared to the anamorph of N. demonbreunii. It is also compared to the atypical Chrysosporium merdarium and to several other Chrysosporium species with echinulate to verrucose–tuberculate conidia, isolated from guano, dung, and nitrogen–rich soils in caves. The onygenalean fungi isolated from any kind of dung are discussed and their facultative coprophily ascribed to variable faecal contents of keratin or other degradable substances. A key to the families and genera of the Onygenales is provided.

Rodentomyces, a new hypocrealean genus from Italy

An ascomycete with non stromatic, narrowly ovoidal or subpyriform, pale yellow to luteous perithecia, a Nectria-like centrum, yellowish-brown reticulate ascospores, and a Trichothecium-like anamorph has been isolated from small rodent dung in Italy. Based on morphological, cultural and molecular (nrLSU and ITS sequences) data, a new genus, Rodentomyces, and a new species, R. reticulatus, are therefore introduced to accommodate this fungus. Rodentomyces represents a hypocrealean genus in the Nectriaceae. Within this family, and based on molecular data, R. reticulatus is placed in the group including Calonectria, Leuconectria, Nectricladiella, Neonectria and Nectria mariannaeae. Several coprophilous genera are recorded in Hypocreales almost evenly distributed among the main families of this order.