zygomycetes

Zygomycetes are a traditional grouping of fungi, historically recognized as the phylum Zygomycota. They are characterized by coenocytic (aseptate) hyphae, rapid growth, and a life cycle that includes both asexual and sexual reproduction. They are commonly saprotrophs on decaying organic matter and can be plant parasites; some species are opportunistic pathogens of animals, including humans.

Asexual reproduction in zygomycetes occurs through sporangia that produce sporangiospores on specialized hyphae called sporangiophores. Sexual reproduction involves the fusion of compatible hyphae (plasmogamy) and subsequent fusion of nuclei (karyogamy) to form a thick-walled zygospore inside a structure called a zygosporangium. When conditions are favorable, the zygospore germinates to produce new hyphae, which can then form sporangia and continue the cycle.

Zygomycetes include species with economic and health significance. Some are used in food production and fermentation, such as Rhizopus species involved in tempeh and bread molding. Others contribute to food spoilage. In medicine, some Rhizopus and Mucor species can cause mucormycosis, a serious opportunistic infection in susceptible individuals. Modern fungal taxonomy places many former zygomycetes in other subgroups (such as Mucoromycotina, Zoopagomycotina, and Entomophthoromycotina), reflecting changes in classification, though the term remains in use in historical literature and general descriptions.