Actinomycota (Actinomycetes)a group of PROKARYOTIC organisms in the form of Gram-positive bacteria (see GRAM'S STAIN which develop branching HYPHAE (0.5–1.0 μm in diameter). The hyphae in turn form a MYCELIUM. Reproduction is either by total FRAGMENTATION of the hyphae and/or by production of SPORES in specialized areas of the mycelium. Most species are SAPROPHYTES, AEROBES, MESOPHILIC, and grow optimally at neutral pH.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005