ABSTRACT
Lipids, as a subject for chemical studies, are often overlooked in fungi, whereas other compounds such as nucleic acids, polysaccharides, proteins, enzymes, and secondary metabolites have been given more attention. The current state of the field is hindered by a lack of studies which take a standardized approach and/or are based on inappropriate methods. Ubiquinones are a chemical class of terpenoid lipids which are used in microbial chemotaxonomy because of the structural variation observed between some taxa. Theoretically, fungal ubiquinones can provide greater discriminating power than bacterial ones, as both partially saturated and saturated structures are found, whereas only the latter have been detected from bacteria. The ambiguities inherent in employing different methods for ubiquinone analysis in fungal taxonomy have been alluded to, and concerns about the validity of some previous approaches are relevant to this issue. Steroids have not been studied adequately as taxonomic characters.
