The document discusses the fungus Rhizopus, which belongs to the phylum Zygomycota. It describes the structure of Rhizopus including its mycelium, hyphae consisting of rhizoids, stolons, and sporangiophores. The document outlines the asexual reproduction of Rhizopus involving the formation of sporangiospores in sporangia. It also summarizes the sexual reproduction requiring fusion of compatible mating types to form zygospores. Finally, it provides brief descriptions of two Rhizopus species - R. stolonifer and R. oryzae.

1. Present By : Jinal Mehta
T.Y.BSC (microbiology)

3. 1. Basidiomycota 2. Ascomycota 3. glomeromycota
4. zygomycota 5. chitridiomycota 6. microsporidia

4.  Kingdom : Fungi
 Phylum:Zygomycota(“Pin”OR “Sugar”mold)
 Class : Zygomycetes(Phycomycetes)
 Order : Mucorales
 Family : Mucoraceae
 Genus : Rhizopus

5. ZYGOMYCOTA
 The name ZYGOMYCOAT refers to the
ZYGOSPORANGIA characteristic during
sexual reproduction .
 ZYGO = Joining ( It referring to the
FUSION of TWO HYPHAL STRANDS which
produces these SPORES. )
 MYCOTA = Suffix ( It referring to a division
of FUNGI. )

6.  WHY IT IS KNOWN AS “PINMOLD”
• Many Members of the ZYGOMYCOTA produce unbranched
sporangiophores with the sporangium for a ‘HEAD’ , A Structure that
superficially resembles a pin ; hence the common name of
ZYGOMYCOTA is “PIN MOLD” .
 WHY IT IS KNOWN AS “SUGARMOLD”
• Many Species commonly cause
economically destructive rotes of
fruits in storage.
• These fruits include STRAWBEERY ,
SWEETPOTATO are high in simple
sugars such as GLUCOSE .
• So It is also Known As “SUGAR -
MOLD” .

7. GENUS : RHIZOPUS
 The name Rhizopus was first named by “EHRENB” in 1820.
 There are around 8-10 known species of Rhizopus .
 They are Saprophytic OR Parasitic .
1. Saprophytic : Grow on Decaying Organic Matter .
2. Parasitic : cause disease on Living Organism .

8. STRUCTURE OF RHIZOPUS

9.  MYCELIUM :
It is Coenocytic , Tubular ,
Multinucleated , Vacuolated & Consist of
Cytoplasmic Materials Like Golgi Body ,
Mitochondrial ETC .
 The reserve food material is in the form
of Glycogen & oil droplets .
 A cell-wall of THULLUS is non-cellulose
& made of chitin .
 HYPHAE OF RHIZOPUS :
It differentiates into THREE distinctive parts .
 Namely “STOLON” , “RHIZOIDS” , “SPORANGIOPHORES” .
 For the growth of Rhizopus , the most important factor is
MOISTURE or WATER availability .

10. 1) RHIZOIDS :
It is NODAL REGION which forms when the stolon touches the surface
of the substratum.
 Rhizoid is the much-branched structure that forms
under the substratum.
 Its main function is to INVADE all the NUTRIENTS from the substratum.
2) STOLON :
It is the INTERMODAL REGION which also refers to runner.
 A stolon is the AERIAL HYPHAE which grow horizontally & is found
attached to the substratum.
 It is aseptate branched & lacks cross walls.
3) SPORANGIOPHORES :
It is REPRODUCTIVE hyphae.
 It grow VERTICALLY from the stolon.
 Sporangiophores are unbranched , elongated , columellate & give rise
to the reproductive structures refers to SPORANGIOSPORES.

11.  CELL-WALL :
The cell-wall of hyphae is
composed of CHITIN CHITOSAN ,
LIPID , PROTEINS etc.
 COLUMELLA :
It arises from the Sporangiophore
which is generally dome or Umbrella-
shape .
 Surface of Columella can be smooth or rough.
 Main function is absorption of the water.
 SPORANGIUM :
It connects with the columella & long sporangiophore.
 Shape of Sporangium is spherical or Globose.
 It carries the reproductive structure refers as Sporangiospore.

12. REPRODUCTION IN RHIZOPUS
 It Reproduces by Vegetative , Asexual &
Sexual methods.
VEGETATIVE REPRODUCTION
• Some time the thallus of the Rhizopus breaks
accidentally or some other factors into few
fragments where each fragment give rise to a new
thallus on favorable condition.

13. OVERVIEW ON RHIZOPUS REPRODUCTION

14. ASEXUAL REPRODUCTION

15. ASEXUAL REPRODUTION STEPS
1. The vegetative hypha grows
to form SPORANGIOPHORE
that is long & slender.
2. Then sporangiophore
develops & enlarge at the
apical region to form
COLUMELLA which is
variable shape & size.

16. 3. The columella give rise to the large , round SPORANGIUM
by pushing cytoplasmic material to the peripheral wall.
4. After that , differentiation of sporangium & columella ,
SPORE SAC is present which carries the
SPORANGIOSPORES. The structure of sporangiospores is
oval , unicellular , multicellular & non-motile.
5. These Sporangiospores multiply their number in the spore
sac & in extreme conditions , it ruptures the sporangial wall
& releases out of the wall.
6. In the environment , the sporangiospores remain in a
dormant state or in a resting state.
7. When favourable conditions return , these sporangiospores
form GERM TUBE & undergo GERMINATION to form a
VEGETATIVE HYPHAE.

17. SEXUAL REPRODUCTION

18.  Sexual Reproduction Requires Compatible Strain Of
Opposite Mating Types Like + & – . ( They are not
Morphologically distinguishable as Male OR Female. )
1) First + & - Thallus Conjugated with
Each Other , So Rhizopus is Also Known
As “Conjugated Fungi”.
2) Two Mating Strain Close each And
Produce a Different Harmon , Called a
PHEROMONE That Causes their Hyphae
That Known as PROGAMETANGIA .This
Mature into GAMETANGIA .
3) After Fusion of Gametangia the Nuclei of the Two
Gametes Fuse forming a ZYGOTE.

19. 4) The Zygote develops a THICK ,
ROUGH , BLACK COAT & become
a dormant ZYGOSPORE.
5) Meiosis Often Occurs at the time Of
germination.
6) The Zygospores Then Splits open &
Produces a Hyphae that bears an ASEXUAL
SPORANGIUM to begin the cycle Again.

20. 1) Rhizopus stolonifer :
• R. stolonifer first discovered by
Christian Gottfried in 1818 as
R. nigricans .
• The name change by J. P.
vuillemin in 1902 as R. stolonifer.
• R. stolonifer is a threadlike mold.
• Common name of R. stolonifer is
bread mold .
• It is depend on sugar OR starch
for its source of carbon substances
for food.
• It use food matter , generally breads or soft fruits , like
grapes or strawberry as a food source for growth , nutrition
& reproduction .

21. 2) Rhizopus oryzae :
• R. oryzae was discovered by Frist
went & Handrik geerligs in 1895.
• It found in various soils across the
world .
• In east asia it is common in
peanuts.
• It is present in maize , pistachios , wheat , barley ,
potatoes , & various tropical food
• It is also cause food poisone.