Ascomycetes

(redirected from ascomycete)
Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
Related to ascomycete: deuteromycete, basidiomycete

Ascomycetes

[‚as·kō‚mī′sēd·ēz]
(mycology)
A class of fungi in the subdivision Eumycetes, distinguished by the ascus.

Ascomycetes

 

a class of higher fungi with about 2,000 genera, embracing 15,000 species. Ascomycetes are characterized by a multicellular mycelium and special spore-bearing organs, or asci, in which ascospores develop. Usually eight spores develop in each ascus. The asci appear as a result of the sexual process, which varies in different ascomycetes. In most species the asci develop internally or on the surface of the fruiting bodies; in Endo-mycetales they develop directly on the mycelium or on the budding cells, without formation of a fruiting body. The classification of ascomycetes is based on the structure of the fruiting bodies and the asci.

Many ascomycetes, including Plectascales, Perisporiales, and Pyrenomycetes, also reproduce asexually by means of conidia; this form of reproduction precedes the formation of asci at the end of the developmental cycle. In many fungi asci seldom develop; these fungi reproduce almost exclusively by means of conidia. A fungus of which only the conidial stage is known is often described as an independent, or imperfect, fungus. An ascomycete that produces conidia under one set of conditions often may not produce them under another.

Most ascomycetes live as saprophytes in soil, on dead plant tissues, on substrates of organic origin (manure, skin, hair), in food products, and in fermenting liquids. Ascomycetes include parasites of higher plants and the causative agents of mycoses in animals and humans. The vegetative period of some species is spent in the conidial stage as parasites on living plants; after the death of the plants the fungi transfer to saprophytic nutrition, forming spore-bearing asci by spring. Almost all fungi that participate in the formation of lichens are ascomycetes.

Many ascomycetes are the causative agents of diseases of cultivated and beneficial wild plants. They cause powdery mildew, canker, spot, scab, snow mold, and root rot. The conidial stages of many species cause spoilage of food products and feeds. Certain types of mold fungi (the genus Penicillium) are used in the production of cheese, bread, and antibiotics. Some ascomycetes are edible, for example, morels and truffles.

V. A. MEL’NIK

References in periodicals archive ?
There have been quite a number of researches on heterologous expression of laccase gene from basidiomycetes in ascomycetes (which serve as the host), however none has shown the production of laccase enzyme from the yeast strains.
A revision of the classification of the Ascomycetes with special emphasis on the Pyrenomycetes.
Although we did not examine the osmotolerance of the yeast species isolated in this study, several of the ascomycete yeasts isolated are known to be osmotolerant (see Pozo et al.
Faccal pellets of lichcnivorous mites contain viable cells of the lichen-forming ascomycete Xanthoria parietina and its green algal photobiont, Trebouxia arboricola.
Informal conversations led to a cooperative research and development agreement (CRADA) to tap a virtual treasure of some 500 ascomycete species.
The book closes with a consideration of the fundamental role of genetic control in the ageing process of the Ascomycete Podospora anserina (H.
Nearly 1500 species of ascomycete and basidiomycete yeasts are included, each description offering not only standard morphological and physiological characters, but also information on systematics, habitat, ecology, agricultural and biotechnological applications and clinical importance.
White-nose syndrome (WNS) is an often lethal parasitic infection of bats that is caused by Pseudogymnoascus destructans, formerly Geomyces destructans (Minnis and Linder, 2013), a psychrophilic and keratinophylic ascomycete fungus (Blehert et al.
A common fungus associated with these plants is an Ascomycete that forms a subterranean structure commonly called a deer truffle.
lophii, though most similar to a sequence from the ascomycete Emericella nidulans, is nevertheless substantially divergent from fungal chitin synthase sequences.