ABSTRACT
Several thermophilic fungi have been isolated and identified during the last five decades, but their identification remains obscure or has not been done authentically. These fungi mostly belong to Zygomycetes, Ascomycetes, and Deuteromycetes (Anamorphic Fungi). No Myxomycetes or Basidiomycetes have been reported as true thermophiles. Of the current less than 50 truly thermophilic fungi, more than 50% belong to Ascomycetes. The most current classification of fungi utilizes recent molecular, multigene phylogenetic studies and characteristics of their sexual and asexual reproductive structures, as well as spores to separate or delimit the groups. Fungal taxonomy is in a state of chaos, particularly the thermophilic species frequently used in applied research. A critical reappraisal of taxonomic descriptions and the status of known thermophilic fungi indicating their natural occurrence and geographic distribution was undertaken in this chapter. Most of the taxonomic descriptions are accompanied by relevant photomicrographs or drawings of their reproductive structures and cultural characteristics. A key to the identification of thermophilic fungi helps the reader to easily identify the thermophilic isolates. Further nomenclatural disagreement and synonymies of important thermophilic fungi are presented and discussed.
