Classification of Fungi PowerPoint that is important to understand by the students

Classification of Fungi PowerPoint that is important to understand by the students

1. Fungi classification
and
Characterization

15. Classification of Fungi
Fungi are classified according to their
structure and method of reproduction.
The four main groups of fungi are:
Common molds (Zygomycota)
Sac fungi (Ascomycota)
Club fungi (Basidiomycota)
Imperfect fungi (Deuteromycota)

16. The Common Molds
Familiar molds that grow on meat,
cheese, and bread are members of the
phylum Zygomycota.
Zygomycetes have life cycles that
include a zygospore.
A zygospore is a resting spore that
contains zygotes formed during the
sexual phase of the mold's life cycle.

17. Structure and Function of Bread Mold
 
Black bread mold, Rhizopus stolonifer,
is a zygomycete.
Black bread mold has two types of
hyphae:
Rhizoids are rootlike hyphae that
penetrate the bread's surface.
Stolons are stemlike hyphae that run
along the surface of the bread.

18. Life Cycle of a Black Bread Mold
Asexual
Reproduction
Sexual
Reproduction
MEIOSIS
FERTILIZATION

19. Life Cycle of a Black Bread Mold
Hyphae from different mating types fuse and
produce gamete-forming structures called
gametangia.
- Mating type (N)
+ Mating type (N)
Stolon
Rhizoids
Gametangia

20. Life Cycle of a Black Bread Mold
Haploid (N) gametes
produced in the
gametangia fuse with
gametes of the opposite
mating type to form
diploid (2N) zygotes.
Zygotes develop into thick-
walled zygospores.

21. Life Cycle of a Black Bread Mold
In favorable conditions,
the zygospore
germinates, undergoes
meiosis, and releases
new haploid spores.
Spores (N)
Sporangium
Zygospore (2N)
Zygospore (2N)
Sexual
Reproduction
MEIOSIS

22. Life Cycle of a Black Bread Mold
Spores (N)
Sporangiophore
Rhizoids
Sporangium
Asexual
Reproduction

23. The Sac Fungi
The phylum Ascomycota is named for
the ascus, a reproductive structure that
contains spores.
The life cycle of an ascomycete usually
includes both asexual and sexual
reproduction.

24. Life Cycle of Sac Fungi
Sexual
Reproduction
Asexual Reproduction

25. Life Cycle of Sac Fungi
In asexual reproduction,
spores called conidia
form at tips of
conidiophores.
Conidiophores are
specialized hyphae.

26. Life Cycle of Sac Fungi
Gametangia
- Mating type (N)
+ Mating type (N)
Hyphae (N)
Hyphae
(N) + (N)
During sexual reproduction,
haploid hyphae of two different
mating types (+ and - ) grow
close together.

27. Life Cycle of Sac Fungi
The N + N hyphae then produce a fruiting
body in which sexual reproduction
continues.
The ascus forms within the fruiting body.
Within the ascus, two nuclei of different
mating types fuse to form a diploid zygote
(2N).

28. Life Cycle of Sac Fungi
Ascus (N + N)
Fruiting body (N + N)
Zygote (2N)
Asci

29. Life Cycle of Sac Fungi
The zygote divides by meiosis, producing
four haploid cells.
In most ascomycetes, meiosis is followed by
mitosis, so that eight cells called
ascospores are produced.
An ascospore can germinate and grow into a
haploid mycelium.

30. Life Cycle of Sac Fungi
Hypha (N)
8 Ascospores
(N)
Ascus

31. The Sac Fungi
Yeasts
Yeasts are unicellular fungi.
Yeasts reproduce asexually by budding.
Dry granules of yeast contain ascospores,
which become active in a moist
environment.

32. 13.04.09 Phase I/ Module VII Dr
Ekta, Microbiology
32
3. Basidiomycetes
Sexual fusion results in the formation of a
club shaped organ called base or basidium
which bear spores called basidiospores

33. 4. Deuteromycetesor Fungi imperfectii
Group of fungi whose sexual phases are
not identified.
Grow as molds as well as yeasts.
Asexual stage – conidia
e.g. Candida, Cryptococcus

34. Fungal Infections/ Mycoses
Superficial mycoses:
2 types: surface and cutaneous mycoses
Skin, hair & nails.
Mild but chronic disease
Deep mycoses:
2 types: subcutaneous & systemic mycoses
Caused by soil saprophytes
Infection is accidental
Range from a symptomatic infection to fatal disease

35. 35
Superficial: Surface mycoses
Live exclusively on dead surfaces of
skin and its appendages

No contact with living tissue, hence
no inflammatory response
1.Tinea versicolor
2.Tinea nigra
3.Piedra

36. 36
Superficial: Cutaneous mycoses
Cornified layer of skin & its appendages
Contact with living tissue, hence
inflammatory & allergic responses seen
1.Dermatophytes – skin, hair & nails
2.3 genera - Trichophyton
Microsporum
Epidermophyton

37. 37
Deep mycoses
Subcutaneous mycoses
1.Mycotic Mycetoma
2.Chromoblastomycoses
3.Sporotrichosis
4.Rhinosporidiosis
Systemic mycoses
1.Cryptococcoses
2.Blastomycosis
3.Coccidioidomycoses
4.Histoplasmoses

38. Candidiasis
Caused by candida sps, forms a bridge
between superficial & deep mycoses as
it can cause cutaneous as well as
systemic infections
Can also cause opportunistic infections

39. Opportunistic infections
Pts with debilitating disease, altered
physiological state
Mainly caused by fungi which are common
lab contaminant on culture media
Aspergillus

Pencillium
Mucor
Rhizopus
Produce serious & fatal infections

40. Useful Properties of Fungi
Source of food
e.g. mushrooms
Fermentation - Production of
alcohol, bread, cheese
e.g.
Sacchromyces spps
Antibiotic production
e.g. Penicillin from
Penicillium notatum

41. Useful Properties of Fungi
Ergot from Claviceps
purpurea, used to induce
uterine contractions
Vaccines for Hepatitis B –
Sacchromyces cerevisiae