Zygomycota (paraphyletic)

Conjugated Fungi

Estimated Species 1,000-1,500 in traditional grouping, taxonomy under revision

Taxonomic Classification

Kingdom: Fungi
Phylum: Zygomycota

Overview

Zygomycota (now recognized as paraphyletic and divided into Mucoromycota and Zoopagomycota) represents an ancient lineage of fungi, primarily known as bread molds and soil fungi. These organisms are characterized by their coenocytic hyphae (lacking septa) and formation of zygospores during sexual reproduction. Most are fast-growing saprotrophs, though some form beneficial associations with plants or are parasites.

Key Characteristics

  • Coenocytic (non-septate) hyphae in most species
  • Sexual reproduction produces thick-walled zygospores
  • Asexual reproduction via sporangia producing sporangiospores
  • Mostly terrestrial, some aquatic species
  • Often fast-growing and opportunistic
  • Generally lack flagellated cells

Ecological Role

Primarily decomposers of organic matter, particularly in soil environments. Some species form endomycorrhizal associations with plant roots. Others are parasites of small soil animals, insects, or other fungi. Important in nutrient cycling and soil ecosystem functioning.

Diversity

Approximately 1,000-1,500 described species in former Zygomycota grouping

Reproduction

Sexual reproduction involves fusion of specialized hyphae to form a zygosporangium containing a zygospore. Asexual reproduction is more common, producing sporangiospores in sporangia on aerial hyphae.

Distribution

Worldwide in soil, organic debris, and as decomposers; some species in aquatic environments

Notable Features

  • Include common bread molds (Rhizopus species)
  • Fast colonizers of nutrient-rich substrates
  • Some species produce fermented foods (tempeh)
  • Include both beneficial and pathogenic species
  • Some are important in traditional Asian fermented foods
  • Certain species cause mucormycosis in immunocompromised individuals

Economic Importance

  • Food fermentation (tempeh production)
  • Organic waste decomposition
  • Some species cause food spoilage
  • Emerging opportunistic human pathogens
  • Plant growth promotion in agriculture