Mucoromycota

The Mucoromycota is a small phylum with about 1,000 species of simple fungi. These fungi were formally classified in the phylum Zygomycota; however, molecular analyses indicated that the Zygomycota should be split into two phyla; one of these, the Mucoromycota, contains some fungi that have airborne spores. Although the phylum Zygomycota is no longer a valid phylum name, the fungi in the Mucoromycota are still commonly called zygomycetes. The sexual stage of these fungi is known as a zygospore (zygosporangium), which is a dormant structure that remains in the substrate until environmental conditions are suitable for germination.

The asexual spores of fungi in the Mucoromycota are produced within a sporangium. In many members of this group, the wall of the sporangium breaks down when the spores are mature, and the spores are passively released into the atmosphere. The spores of two genera, Rhizopus and Mucor, are considered allergenic. When culture-based air sampling is used to analyze airborne fungi, these two genera are commonly isolated.