This presentation will be helpful for the students of UG and PG botany.

1. Cunninghamella
Zygomycotina
Dr. Shriram Kunjam
Assistant Professor
Department of Botany
Govt. V.Y.T. PG Autonomous College, Durg (Chhattisgarh)

2. ZYGOMYCOTINA
Systematic position
Subkingdom: Mycota
Division: Eumycota
Sub-division: Zygomycotina
Class: Zygomycetes
These are the second kingdom of fungi known as the conjugated fungi.
They majorly include the bread mold, Rhizopus stolonifer.
Approximately 1060 species are known.

3. General Characteristics
•The division Zygomycota contains the fungi called Zygomycetes.
•These are lower fungi that have non-septate Hyphae and produce endogenous asexual spores,
called Sporangiospores, contained within swollen sac-like structures called Sporangia.
•The Hyphae of Zygomycetes known as Coenocytic, with many haploid nucleoids.
•Zygomycetes also produce sexual spores known as oospores in some fungi and Zygospores in
others.
•Zygospores are tough thick walled zygotes called Zygospores that can remain dormant when the
environment is too harsh for the growth of the fungus.

4. Hyphae
There are 3 types of hyphae present in this fungi-
1.Stolon- This grow horizontally
2.Rhizoids- These are root-like structures present
in tufts. They help in attaching mycelium to the
substratum.
3.Sporangiospores- These are present on the
specialized hyphae. These are majorly erect, Arial
and unbranched hyphae which also grow as tufts.
These are reproductive in nature as they bear
sporangium.

5. Taxonomic Classification
Kingdom: Fungi
Phylum: Zygomycota
Order: Mucorales
Family: Cunninghamellaceae
Genus: Cunninghamella

6. Description and Natural Habitats
Cunninghamella is a filamentous fungus found in soil and
plant material, particularly at Mediterranean and subtropical
zones.
It has also been recovered from animal material, cheese, and
Brazil nuts. In addition to being a common contaminant,

7. Species
The genus Cunninghamella currently contains seven species.
Cunninghamella bertholletiae,
Cunninghamella elegans, and
Cunninghamella echinulata are the most common species,
Cunninghamella bertholletiae is the only known human and animal
pathogen.

8. Cunninghamella
Synonymy:
Cunninghamella elegans, Cunninghamella echinulata var. elegans.
Cunninghamella, a zygomycete in the order Mucorales, is an extremely
rare cause of human infection.
The genus Cunninghamella is characterized by white to grey, rapidly
growing colonies, producing erect, straight, branching sporangiophores.

9. Macroscopic Features
Cunninghamella colonies are rapidly growing (mature in 4 days),
cottony, and white to tannish-gray in color.
The reverse is pale. Cunninghamella elegans produces purely gray
colonies.
 While Cunninghamella bertholletiae may grow at temperatures as
high as 45°C, Cunninghamella elegans fails to grow at this temperature

11. Microscopic Features
Nonseptate or sparsely septate broad hyphae, sporangiophores, terminal vesicles,
sporangioles (sporangiola; sing. sporangiolum), and sporangiospores are visualized.
Sporangiophores are erect and form short lateral branches each of which terminates in a
swollen vesicle.
The vesicle (30-65 µm in diameter) has spine-like denticles on its surface.
Sporangioles (5-8 x 6-14 µm) are round to oval in shape, one-spored, and are formed on these
denticles. Sporangiospores are one-celled, solitary, and globose to ovoid in shape. The walls of
the spores often have needle-like crystals.

13. Reproduction

14. Asexual reproduction
Asexual reproduction begins with the production of aerial hyphae.
The tip of an aerial hypha, now called a sporangiophore is separated from the vegetative
hyphae by a complete septum called a columella.
The cytoplasmic contents of the tip differentiate into a sporangium containing many
asexual spores.
The spores contain haploid nuclei derived from repeated mitotic divisions of a nucleus
from the vegetative mycelium. Dispersal of the spores is by wind or water.

15. Cunninghamella sp. Is characterized by branched sporangiophores that terminate in a spherical
vesicle from which secondary spherical sporangiolas (tiny sporangia without columella) are derived
from the surface, each attached to the vesicle by a delicate denticle.
Species within this genus are characterized by the asexual production of pedicellate,
unispored sporangia that typically cover the surface of a terminal fertile vesicle (Fig. 1).
The sporangiola are covered with elongate spines at maturity (Fig. 2). During the sexual
phase of its heterothallic (or self-sterile) life cycle, C. echinulata produces ornamented,
reddish-brown zygospores between opposed suspensors (Fig. 3).

16. Fig 1) Pedicellate, unispored sporangia of C. echinulata that typically cover the surface of a terminal
fertile vesicle.
Fig 2) Sporangiola are covered with elongate spines at maturity.
Fig 3) Reddish-brown zygospores between opposed suspensors. Images by Kerry O'Donnell.

20. Reproduction
Sexual Reproduction
Sexual reproduction occurs when opposite mating strains, designated as "+" and "-",
grow towards one another.
As the opposite mating strains near one another a hormone, trisporic acid, induces
formation of progametangia which meet to initiate sexual development.
Nuclei migrate into the apex of the progametangia where septa will form.
The terminal cells are the isogametangia and the remainder of what was the
progametangia are the suspensors.
Fusion of gametangia will take place, followed by plasmogamy and karyogamy, and
zygote formation. A dark, thick cell wall then forms around the zygote which may
now be referred to as a zygospore

21. As a member of the Zygomycota, sexual reproduction in C. bertholletiae is through the formation of zygospores.
Specifically, in the case of C. bertholletiae, heterothallic mating occurs when hyphae of opposite mating types
are stimulated by mutually-secreted pheromones to grow toward each other and differentiate into gametangia.
When they meet, these gametangia fuse (plasmogamy) and form a multinucleate, dikaryotic zygosporangium
flanked by suspensor cells derived from the contributing hyphae.
Each zygosporangium produces one zygospore, which, after a dormant period of weeks to months, undergoes
nuclear fusion (karyogamy) to produce a diploid nucleus.
The diploid nucleus then undergoes meiosis and chromosomes recombine to produce recombinant progeny
genomes.
A germosporangium forms, containing haploid spores, which are released into the environment to initiate the
growth of a new mycelium.

22. Figure 1: Pair of progametangia of different mating strains: "+" and "-" grow
towards each other. Migration of nuclei will occur in the tips of both
progametangia where gametangia will form.
Figure 2: Septa are laid down at the apex of the progametangia
to form isogametangia. The outside, larger cells are
the suspensors that support the gametangia.
Figure 3: Plasmogamy occurs following fusion of the gametangia.
Karyogamyimmediately follows to form a multinucleate zygote.
Figure 4: The zygote will form a thick, pitted wall around itself to form
the zygospore. Further development will not develop until after it has gone
through a period of dormancy.