Mycolaceae

Mycolaceae is a term used in historical bacterial taxonomy for a family of Gram-positive, aerobic, non-spore-forming, rod-shaped bacteria characterized by a thick, lipid-rich cell wall containing mycolic acids. These features result in acid-fast staining and a slow growth rate on routine media. In older classifications, members of this group were placed in the order Mycobacteriales within the phylum Actinobacteria.

Modern bacterial systematics reorganized these lineages, and in contemporary taxonomic frameworks most genera once included in Mycolaceae are placed in the family Mycobacteriaceae or in other families within the order Corynebacteriales. Consequently, Mycolaceae is largely considered obsolete or synonymous with older literature, and is not widely recognized as a valid family in current databases.

Physiology and ecology: The organisms associated with the historical Mycolaceae are typically aerobic and may be environmental saprophytes or pathogens. The best-known clinically relevant taxa in this broad group are the mycobacteria, which include pathogens causing tuberculosis and leprosy; in current taxonomy such taxa reside in Mycobacteriaceae. Beyond pathogens, many non-tuberculous mycobacteria inhabit soil and water and can have environmental roles or occasional opportunistic infections.