Fungalpedia – Note 3307, Basidiobolomycetes
Basidiobolomycetes Doweld, Prosyllabus Tracheophytorum, Tentamen Systematis Plantarum Vascularium (Tracheophyta) (Moscow): LXXVII (2001).
Citation when using this data: Wijayawardene NN et al. 2024 – Fungalpedia.
Index Fungorum, Faceoffungi, MycoBank, GenBank, Fig 1.
Classification: Basidiobolomycotina, Basidiobolomycota, Basidiobolomyceta, Fungi.
Cells in their vegetative state possess a single nucleus and can manifest either as a septate mycelium or as yeast-like cells that originate from the insides of preceding cells, exemplified by the ‘Darmform’ growth pattern. During mitosis, the nuclear membrane starts by breaking into pieces. These fragments, alongside other membranes, accumulate around a specific nuclear area. The chromosomes, which are numerous and minuscule, get compacted and position themselves on a central metaphase plate. This plate typically embeds within the nucleolus, working in conjunction with a barrel-shaped spindle. During the interphase, these chromosomes relax and expand. The cell responsible for producing conidia, known as the conidiophore, is straightforward but showcases a distinct bulbous enlargement at its tip, directly below the emerging conidium. Conidia are spherical, with a single nucleus, and have a tiny conical outgrowth at their base. This outgrowth juts into the spore body but flips out during release. The wall layers of the conidia are indistinguishable. The release of these conidia is quite forceful, resembling a rocket’s propulsion, which is triggered by a rupture in the central frail region of the sub-conidial enlargement. The upper part of this enlargement is released with the conidium and can occasionally separate during its movement. If secondary conidia are produced, they are typically elongated, sometimes bent, and may have a mucous drop at their tip. These are formed at the top of a slender, long conidiophore and are dispersed passively. Resting spores, generally zygospores, are developed within the axis of preceding cells. The nuclei of the gametangial cells divide before merging, but only a single nucleus from each cell becomes part of the zygospore. Once matured, zygospores exhibit robust, double-layered walls. Their germination directly results in a germ conidium, typically resembling the secondary type, which is elongated and passively released from a thin conidiophore (modified description from Humber 2012).
Life modes and distribution: Although Basidiobolomycetes are mostly known for their saprophytic lifestyle, there are a few species that can cause rare infections in humans and animals. Basidiobolus ranarum is the most well-known species responsible for infections, which are known as basidiobolomycosis. These infections often affect the subcutaneous tissue, gastrointestinal tract, or rhinofacial regions (Eidam 1886; Benjamin 1979).
Notes: Similar to notes in the phylum.
Type order: Basidiobolales Jacz. & P.A. Jacz. (1931), Opredelitel’ Gribov, I Ficomiţeti (Leningrad): 8 (1931).
Type family: Basidiobolaceae Engler & Gilg (1924), Syllabus, Edn 9 & 10 (Berlin): 45 (1924).
Type genus: Basidiobolus Eidam 1886 [Amphoromorpha Thaxter 1914], Krypt.-Fl. Schlesien (Breslau) 3.1(9–16): 224 (1886) [1889].
Type species: Basidiobolus ranarum, Krypt.-Fl. Schlesien (Breslau) 3.1(9–16): 225 (1886) [1889].
Other accepted species: Species Fungorum – search Basidiobolomycetes.
Figure 1 – Culture and micromorphological characteristics of Basidiobolus omanensis (CBS 146282). a, b Colony after 7 days of incubation at 28°C. a MEA front. b PDA front. c Primary conidia. d Primary conidia arising from mycelia. e Young zygospore. f Zygospores. g Mature conidia. h Capilloconidium. i Conidia with sharp-pointed papillae projection with beak. j Smooth mature sexual zygospore. k Numerous primary conidia. Scale bars c-k = 10 µm.
References
Benjamin RK. 1979 – Zygomycetes and their spores. Whole Fungus 2:573–262.
Entry by
Nalin N. Wijayawardene, Center for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing, Yunnan 655011, P.R. China, Tropical Microbiology Research Foundation, 96/N/10, Meemanagoda Road, 10230 Pannipitiya, Sri Lanka, Department of Bioprocess Technology, Faculty of Technology, Rajarata University, Sri Lanka
Published online 29 September 2026