# Mucor
**Mucor** is a genus of fast-growing molds in the fungal family Mucoraceae, order [Mucorales](https://www.edgepedia.org/mucorales), phylum Mucoromycota, characterized by rapidly growing coenocytic (non-septate) hyphae and globose sporangia borne on simple or branched sporangiophores.[1](https://pubchem.ncbi.nlm.nih.gov/taxonomy/Mucor) • [2](https://doi.org/10.1128/cmr.13.2.236) Species are ubiquitous in nature, colonizing wet organic materials as saprobes, and the genus is generally not considered pathogenic, although some species cause opportunistic human infections.[1](https://pubchem.ncbi.nlm.nih.gov/taxonomy/Mucor) • [3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/)
| Key fact | Detail |
|---|---|
| Classification | Family Mucoraceae, order Mucorales, subphylum Mucoromycotina, phylum Mucoromycota[1](https://pubchem.ncbi.nlm.nih.gov/taxonomy/Mucor) • [4](https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=4827&lin=f&lvl=2&mode=Info) |
| Growth form | Rapid-growing, coenocytic hyphae; globose sporangia on solitary or branched sporangiophores[2](https://doi.org/10.1128/cmr.13.2.236) |
| Sexual reproduction | Zygospores, thick-walled pigmented zygotes formed by fusion of two hyphal ends[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/) |
| Rhizoids | Absent in typical Mucor species; Mucor irregularis is an exception among Mucor species in having rhizoids[5](https://academic.oup.com/ofid/article/10/1/ofac559/6974385) |
| Identification | ITS (internal transcribed spacer) sequencing is the method of choice for species identification in Mucorales[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/) |
| Best-studied species | Mucor circinelloides, a dimorphic fungus producing hydrolytic enzymes, lipids, carotenoids, and ethanol[6](https://www.tandfonline.com/doi/full/10.1080/07388551.2019.1592104) |
| Medical relevance | Mucor is among the opportunistic genera causing mucormycosis, predominantly in patients with impaired immunity[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/) |
## Taxonomic position
Mucor belongs to the order Mucorales, which the NCBI taxonomy places in the class Mucoromycetes within the phylum Mucoromycota; the order carries the common name "pin molds".[4](https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=4827&lin=f&lvl=2&mode=Info) The Mucorales are among the early-diverging, ancient lineages of fungi, mostly saprotrophic organisms.[7](https://pmc.ncbi.nlm.nih.gov/articles/PMC3734967/)
The higher-level classification changed substantially with molecular phylogenetics. Fungi that reproduce by zygospores were formerly classified in the phylum [Zygomycota](https://www.edgepedia.org/zygomycota), but that phylum was abandoned because multilocus phylogenies did not support it. Genome-scale analyses of 46 taxa by Spatafora and colleagues circumscribed two new phyla, Mucoromycota and Zoopagomycota, with the Mucorales assigned to the Mucoromycota.[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/) As a consequence, the disease term "zygomycosis" was replaced by "mucormycosis" for infections caused by Mucorales.[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/)
## Morphology and identification
Mucor species grow as wide, predominantly aseptate hyaline hyphae with many nuclei per cell; septa form mainly to delimit reproductive structures.[2](https://doi.org/10.1128/cmr.13.2.236) • [3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/) [Asexual reproduction](https://www.edgepedia.org/asexual-reproduction) produces sporangiospores inside globose sporangia, each containing a sterile central vesicle called a columella, on sporangiophores that are either solitary or branched.[2](https://doi.org/10.1128/cmr.13.2.236) • [3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/) When sexual reproduction occurs, it produces zygospores, thick-walled, pigmented, often ornamented zygotes formed by the fusion of two differentiated hyphal ends.[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/)
In laboratory identification, Mucor is distinguished from related genera such as Rhizopus and Lichtheimia by microscopic features including the presence or absence of rhizoids (root-like hyphal extensions) and their position relative to the sporangiophores.[8](https://labtestacademy.com/wp-content/uploads/2025/07/Bailey_and_Scotts_Diagnostic_Microbiology_15e_By_Patricia_Tille.pdf) Most Mucor species lack rhizoids, which separates them from Rhizopus; the exception is Mucor irregularis, formerly [Rhizomucor](https://www.edgepedia.org/rhizomucor) variabilis, which was transferred to Mucor on the basis of rDNA phylogeny and is somewhat unique among Mucor species in having rhizoids.[5](https://academic.oup.com/ofid/article/10/1/ofac559/6974385)
Molecular identification relies on sequencing the internal transcribed spacer (ITS) region, which has been shown to reliably distinguish species in Mucorales, including all species in Mucor.[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/) • [9](https://pmc.ncbi.nlm.nih.gov/articles/PMC3734965/) Conventional multilocus phylogenetics is complicated in Mucor because several traditionally used markers are not single-copy genes: the genes for actin, translation elongation factor-1 alpha (tef), beta-tubulin, and calmodulin all possess paralogs in Mucor.[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/) For the clinically relevant Mucor circinelloides complex, a revised species concept added new markers including mcm7, rpb1, tsr1, and a cyclopropane-fatty-acyl-phospholipid-synthase gene (cfs), together with a comparative study of zygospore quantity and quality.[10](https://pmc.ncbi.nlm.nih.gov/articles/PMC7567969/)
## Ecology and economic uses
Mucorales colonize all kinds of wet organic materials and are a permanent part of the human environment, acting as pioneers, agents of rot and spoilage, and ingredients of cheese and soy products.[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/) Mucorales have been used for centuries to ferment traditional Asian and African foods, are used for several European cheese varieties, and serve in biotechnology as producers of a broad spectrum of enzymes and for biotransformation of medically important compounds such as steroids and terpenoids.[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/)
The best-studied species, Mucor circinelloides, is a dimorphic fungus able to produce a wide variety of hydrolytic enzymes, lipids suitable for biodiesel production, carotenoids, ethanol, and biomass with significant nutritional value, which has made it a candidate for biorefinery applications.[6](https://www.tandfonline.com/doi/full/10.1080/07388551.2019.1592104)
## Medical importance
Although Mucor species are generally not considered pathogenic,[1](https://pubchem.ncbi.nlm.nih.gov/taxonomy/Mucor) the genus is listed among the opportunistic genera of the Mucorales that cause mucormycosis, a life-threatening infection occurring predominantly in patients with impaired immunity.[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/) Of the 261 species accepted in the order Mucorales, 38 have been reported to cause human infections.[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/) Mucormycoses are generally angioinvasive, have an acute course, and in tissue show broad, belt-like, non- or rarely-septated hyphae.[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/)
## Taxonomic challenges and ongoing change
Mucor is a species-rich, polyphyletic genus that lacks a state-of-the-art taxonomy; recent taxonomic studies have been limited to species from particular habitats, such as clinical samples or cheese, and do not cover the complete diversity of the genus.[11](https://hdl.handle.net/2066/221477) New species continue to be described: Mucor soli was described in 2024 from a holotype in Brazil,[12](https://ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?command=show&id=3421023&lvl=&mode=node) Mucor cerradoensis in 2025,[13](https://ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?command=show&id=3450351&lvl=3&mode=node) and a 2025 study from China described six new Mucor species, noting that missing or incomplete sequences of key markers such as RPB1, ITS, and LSU in some strains hinder species delimitation.[14](https://www.mdpi.com/2309-608X/12/2/98)
## References
1. [Mucor – Taxonomy, PubChem](https://pubchem.ncbi.nlm.nih.gov/taxonomy/Mucor)
2. [Zygomycetes in Human Disease, Clinical Microbiology Reviews](https://doi.org/10.1128/cmr.13.2.236)
3. [Walther G, Wagner L, Kurzai O (2019). Updates on the Taxonomy of Mucorales with an Emphasis on Clinically Important Taxa. Journal of Fungi](https://pmc.ncbi.nlm.nih.gov/articles/PMC6958464/)
4. [NCBI Taxonomy Browser: Mucorales](https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=4827&lin=f&lvl=2&mode=Info)
5. [Kidd SE, Abdolrasouli A, Hagen F (2023). Fungal Nomenclature: Managing Change is the Name of the Game. Open Forum Infectious Diseases](https://academic.oup.com/ofid/article/10/1/ofac559/6974385)
6. [Critical applications of Mucor circinelloides within a biorefinery context. Critical Reviews in Biotechnology (2019)](https://www.tandfonline.com/doi/full/10.1080/07388551.2019.1592104)
7. [Hoffmann K et al. (2013). The family structure of the Mucorales: a synoptic revision based on comprehensive multigene-genealogies](https://pmc.ncbi.nlm.nih.gov/articles/PMC3734967/)
8. [Hyaline Molds, Mucorales, Basidiobolales, Entomophthorales, Dermatophytes (Bailey & Scott's Diagnostic Microbiology, 15th ed.)](https://labtestacademy.com/wp-content/uploads/2025/07/Bailey_and_Scotts_Diagnostic_Microbiology_15e_By_Patricia_Tille.pdf)
9. [DNA barcoding in Mucorales: an inventory of biodiversity](https://pmc.ncbi.nlm.nih.gov/articles/PMC3734965/)
10. [Wagner L et al. (2020). A new species concept for the clinically relevant Mucor circinelloides complex](https://pmc.ncbi.nlm.nih.gov/articles/PMC7567969/)
11. [Taxonomy of the Mucor circinelloides complex (Wagner et al.)](https://hdl.handle.net/2066/221477)
12. [NCBI Taxonomy Browser: Mucor soli](https://ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?command=show&id=3421023&lvl=&mode=node)
13. [NCBI Taxonomy Browser: Mucor cerradoensis](https://ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?command=show&id=3450351&lvl=3&mode=node)
14. [Unveiling Species Diversity Within Early-Diverging Fungi from China XII: Six New Species of Mucor. Journal of Fungi (2025)](https://www.mdpi.com/2309-608X/12/2/98)
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*Topic: Encyclopedia › Life and health › Microorganisms and fungi › Fungi and mycology › Other fungal taxa › Mucoromycota and zygomycete lineages › Mucor*
*Initially written Sep 17, 2026 · Reviewed: Oct 21, 2026 · Edited: Oct 15, 2026; Oct 21, 2026 · Last review: Oct 21, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license