zygomycete

Zygomycete is a term traditionally used for fungi that were placed in the former phylum Zygomycota. Members are mostly fast-growing molds associated with decaying organic matter in soil, on food, and in other ecological niches. Because molecular studies reorganized fungal classification, Zygomycota as a formal phylum has been dismantled, and many former zygomycetes are placed in other lineages such as Mucoromycotina (within Mucoromycota) or Zoopagomycota. The term is still used as a practical grouping for these fungi, especially the molds encountered in everyday life and in agriculture.

Zygomycetes are characterized by coenocytic (aseptate) hyphae and a life cycle that includes both asexual and sexual stages. Asexually, they produce sporangia on sporangiophores that release numerous sporangiospores. In sexual reproduction, compatible hyphae fuse (plasmogamy and subsequent karyogamy) to form a thick-walled zygospore within a zygosporangium. Zygospores serve as resistant survival structures in adverse conditions. Some genera also form rhizoids and stolons, particularly among the common Mucorales.

Ecologically, zygomycetes are widespread saprotrophs and can be plant pathogens or opportunistic pathogens of animals and humans (notably mucoralean species). They play a role in the decomposition of organic matter and nutrient cycling. Some species are used in food production and fermentation, such as certain Rhizopus species involved in tempeh and other processes. Overall, zygomycetes represent a diverse, ecologically important, but taxonomically revised group of fungi with both beneficial and harmful interactions.