Rhizopus stolonifer is more commonly known as black bread mold. Rhizopus specifically means any rot causing fungi. This type of mold also has a synonym name of Rhizopus nigricans.


The Breakdown!


Domain: Eukarya

Rhizopus stolonifer is classified as a member of the Eukarya because it has cells that are organized into complex structures that are enclosed within membranes, along with membrane bound nuclei and other organelles in those cells.


Kingdom: Fungi

The kingdom Fungi consists of organisms that are heterotrophic. Rhizopus stolonifer is a mold that lacks chlorophyll, is non-motile, filamentous, and a decomposer of organic material.


Phylum: Zygomycota

Rhizopus stolonifer belongs to the phylum Zygomycota because it sexually produces zygospores and is considered saprophytic and parasitic.


Class: Zygomycetes

The Zygomycetes all have chitenous cell walls in a coenocytic mycelium and they lack motile spores.


Order: Mucorales

Rhizopus stolonifer is a member of the Mucorales because it is fast growing, with wide hyphae, that lack septa or is coenocytic, and grow within a substrate. Rhizopus stolonifer is also considered a member of the Mucorales because it is a major saprophyte, or grows and acquires nutrients from dead and decaying matter.


Family: Mucoraceae

Rhizopus stolonifer is a part of the family Mucoraceae due to the key feature of a swollen extension of the sporangiophore, called the columella. It looks like a balloon within the sporangium and it often persists after the spores have been released.


Genus: Rhizopus

Rhizopus stolonifer is a member of the Rhizopus species because it is a rot causing fungus that has columnar hemispherical aerial sporangia anchored to the substrate by rhizoids.


Species: Rhizopus stolonifer

There are multiple species of Rhizopus, but Rhizopus stolonifer earned this species name because it is a black mold that grows on bread and its spores float around in the air. Rhizopus stolonifer also uses rhizoids as a way to anchor itself to the vast array of substrates it can come in contact with.


Identification Tips:


To identify Rhizopus stolonifer look for either a grayish fluffy mass or a blue or yellow colored coating on the substrate. Black spores are also visible to the eye on the surface of the substrate, which may look like black specs. The interesting looking fungi can appear on stale bread, damp leathers, and decaying fruits of which are kept at favorable temperatures.


To explore more about the kingdom of Fungi, the other classifications specifically of Rhizopus stolonifer, and to find out more about other similar interesting information please click here.


Phylogenetic Trees:


I created the phylogenetic tree below and it is modified from an article in the journal Bioscience, Biotechnology, and Biochemistry. In order to create this phylogenetic tree composed on the genus Rhizopus, molecules of the rDNA of the species of the genus were sequenced. Three large clusters composed of the different species are indicated by the letters A, B, and C. The phylogenetic tree represents that the molecular phylogeny is very similar to the current morphological grouping of the Rhizopus species. Molecular techniques are currently being used in order to consider reclassification among many species of the fungi, which is not the case when looking at the results of the Rhizopus species. Rhizopus stolonifer is located within the C cluster.



The phylogenetic tree below was also created by me; it is modified from an article in the journal Cells Stress and Chaperones. It was composed by neighbor-joining different types of fungi by the location of fungal heat shock protein 70 (Hps70s) in their cells. Steroid hormones, such as progesterone, stimulate the abundance of Hps70s in the different types of fungi. The intracellular localization on Hps70s is indicated by the capitalized letters. The Hps70s in Rhizopus stolonifer is located in the cytosol, indicated by being grouped within the letter C; M stands for mitochondria, R stands for ribosome, and ER for endoplasmic reticulum. The ability of Rhizopus stolonifer to produce these steroids, such as progesterone, is the main reason it is able to be used in common birth control pills.



Please move forward to view the habitat of which this mold prefers to uphold.


You can learn about the Shiitake Mushroom, which is another type of fungi, an edible mushroom, in the phylum Basidiomycota.