Fungi can be divided into several groups based on characteristics. Yeasts are unicellular fungi that reproduce through budding or fission. Molds are filamentous and made of hyphae that grow at their tips. Hyphae can be septate or coenocytic. Fungi reproduce both sexually through spores and asexually through fragmentation or spore formation. Major fungal groups include zygomycetes, ascomycetes, basidiomycetes, and deuteromycetes. Zygomycetes reproduce sexually through conjugation of hyphae. Ascomycetes form ascospores within an ascus. Basidiomycetes form mushrooms

2. CHARACTERISTICS OF FUNGI
1.Yeasts
Unicellular fungi, nonfilamentous, typically oval or
spherical cells. Reproduce by mitosis:
Fission yeasts: Divide evenly to produce two new cells
(Schizosaccharomyces).
Budding yeasts: Divide unevenly by budding (Saccharomyces).
Budding yeasts can form pseudohypha, a short chain of
undetached cells.
Candida albicans invade tissues through pseudohyphae.
Yeasts are facultative anaerobes, which allows them to
grow in a variety of environments.
When oxygen is available, they carry out aerobic respiration.
When oxygen is not available, they ferment carbohydrates to produce
ethanol and carbon dioxide.

3. CHARACTERISTICS OF FUNGI (Continued)
2. Molds and Fleshy Fungi
Multicellular, filamentous fungi.
Identified by physical appearance, colony
characteristics, and reproductive spores.
Thallus: Body of a mold or fleshy fungus. Consists of many
hyphae.
Hyphae (Sing: Hypha): Long filaments of cells joined
together.
Septate hyphae: Cells are divided by cross-walls
(septa).
Coenocytic (Aseptate) hyphae: Long, continuous
cells that are not divided by septa.
Hyphae grow by elongating at the tips.
Each part of a hypha is capable of growth.
Vegetative Hypha: Portion that obtains nutrients.
Reproductive or Aerial Hypha: Portion connected
with reproduction.
Mycelium: Large, visible, filamentous mass made up of
many hyphae.

4. Characteristics of Fungal Hyphae:
Septate versus Coenocytic

6. LIFE CYCLE OF FUNGI
 Filamentous fungi can reproduce asexually by fragmentation
of their hyphae.
 Fungal spores are formed from aerial hyphae and are
used for both sexual and asexual reproduction.
1. Asexual spores: Formed by the aerial hyphae of one organism. New
organisms are identical to parent.
 Conidiospore: Unicellular or multicellular spore that is not
enclosed in a sac.
 Chlamydospore: Thick-walled spore formed within a hyphal
segment.
 Sporangiospore: Asexual spore formed within a sac
(sporangium).
2. Sexual spores: Formed by the fusion of nuclei from two opposite
mating strains of the same species. New organisms are different from
both parents.

8. Zygomycota (Conjugation Fungi)
 Also known as bread molds as most of the zygomycetes
are molds
 Saprophytic molds with coenocytic hyphae (lacking
septa).
 Their main source of reproduction is by asexual
reproduction sexual reproduction may occur by the
process of conjugation.
 It has the sporangiospore which is an asexual spore
enclosed within a sporangium

9.  Sexual Reproduction: Occurs through conjugation, the
joining of hypha of two different strains (plus and minus).
 Zygospores: Sexual spores which are enclosed in a thick,
resistant wall.
The zygomycetes are generally not pathogens though
Rhizopus nigricans: (Common black bread mold.) May cause opportunistic
infections in diabetes patients

10. Life Cycle of a Zygomycete: Black Bread Mold (Rhizopus)

11. Ascomycota (Sac Fungi)
Include common antibiotic producing fungi and yeasts,
and several human pathogens.
They are lichens, decomposers and pathogens and also
molds with septate hyphae
Characterised by an extensive heterokaryotic stage
during the formation of ascocarps which are the sexual
spores and also the fruiting body
Asexual Reproduction: Conidiospores not enclosed in
a sac. Become airborne easily. Form chains (broom-like
structures).
 Sexual Reproduction: Ascospores enclosed in a sac-
like structure (ascus).

12. Examples of ascomycetesPenicillium notatum (Produces penicillin)
Saccharomyces (Brewer’s yeast)
Trychophyton (Athlete’s foot)
Aspergillus (Carcinogenic aflatoxin in peanuts),
Blastomyces (Respiratory infections)
Histoplasma capsulatum (Respiratory and systemic
infections)

13. Life cycle

15. basidiomycota
• Mainly the mushrooms
• Club shaped reproductive structure
• Mainly food and also associated with plant diseases
• Life cycle includes a long lived diakaryotic mycelium
• Mycelium is septate, septa are performed, sometimes
with a dolipore which is doughnut shaped
• Mycelium passes through 2 phases; monokaryotic and
diakaryotic.

16. • Two hyphal ends of the monokaryotic
mycelium ( of different mating types) fuse and
form diakaryotic mycellium.
• The diakaryotic mycellium can divide at the
apical cell and form a form clamp connections.
Clamp
Formation of diakaryotic
mycellium

17. Life cycle of basidiomycota

18. deutromycota
• No longer exist
• Saprophytic, parasitic and predatory
• Many produce conidia
• Most classified as ascomycetes eg pennicilin
is now a ascomycete
• 2200 known species
• No known sexual stage
• Causes ringworm, atheletes, furasim wilt of
tomatoes

19. Reproduce asexually.
Catch-all category for unclassified fungi:
Pneumocystis carinii: Causes pneumonia in AIDS
patients. Leading cause of death in AIDS patients.
Originally classified as a protozoan.
Candida albicans: Causes yeast infections of vagina
in women. Opportunistic infections of mucous
membranes in AIDS patients