This presentation is Useful for B. Pharmacy SEM III Students to study the Topic Fungi According to PCI Syllabus.
It Consist of Morpholoy of Fungi, Cultivation , Reproduction and Classification of Fungi.
2. INTRODUCTION
Fungi is the plural of fungus.
A member of a large group of eukaryotic organisms.
Familiar as mushrooms.
These organisms are classified as a kingdom, Fungi, which is separate
from plants, animals, protists and bacteria.
One major difference is that fungal cells have cell walls that contain chitin,
unlike the cell walls of plants and some protists, which contain cellulose,
and unlike the cell walls of bacteria.
The study of fungi is known as MYCOLOGY. Mycology has often been
regarded as a branch of botany, even though it is a separate kingdom in
biological taxonomy.
Genetic studies have shown that fungi are more closely related to animals
than to plants.
3.
4. Non-motile eukaryotic organisms which exists as saprophytes, parasites.
Posses differentiated nuclei surrounded by a nuclear membrane.
Reproduce either by budding or by forming spores.
Nonphotosynthetic (heterotrophic).
Morphologically may be either simple oval cells or long tubular septate hyphae showing
true lateral branching.
Most fungi grow as thread-like filamentous microscopic structures called hyphae (which
are microscopic filaments between 2–10 µm in diameter and up to several centimeters in
length) and which collectively form the mycelium (aggregates of hyphae).
Hyphae can be septate, i.e., divided into compartments separated by a septum,
each compartment containing one or more nuclei, or can be coenocytic, i.e.,
lacking hyphal compartmentalization.
May be unicellular or multicellular.
Most are microscopic molds or yeasts.
MORPHOLOGICAL CHARACTERISTICS OF FUNGI
5.
6. DIFFERENCE BETWEEN FUNGI AND BACTERIA
Characteristics Fungi Bacteria
Cell type Eucaryotic Procaryotic
Optimum pH 4-6 6.5-7.5
Optimum temperature 25-30oC
(saprophytes) 32-
37oC (parasites)
32-37oC
Cell membrane Sterols present Sterols absent
except
mycoplasm
O2 requirement Strictly aerobic (moulds)
Facultative
anaerobic(Some yeasts)
Aerobic to anaerobic
Light requirement None Some photosynthetic gr.
Carbon source Organic Organic/ Inorganic
Conc. of sugar in media 4-5% 0.5-1%
Cell wall components Chitin, cellulose or hemicellulose Peptidoglycan
Susceptibility to
antibiotics
Sensitive to
griseofulvin,
Resistant to
penicillinis,
chloramphenicol etc.
Sensitive to
penicillinis, Resistant
to griseofulvin,
tetracyclines etc.
9. CLASSIFICATION OF FUNGI
Most fungi reproduce both sexually and asexually.
When environmental conditions are favorable, asexual reproduction occurs
rapidly.
When unfavorable conditions stress the organism, sexual reproduction
occurs and the offspring have an increased likehood that they will be better
suited for the environment.
Oomycete’s Zygomycete’s
Lower True Fungi
Aseptate Mycelium
10. CLASSIFICATION OF FUNGI
Most fungi reproduce both sexually and asexually.
When environmental conditions are favorable, asexual reproduction occurs
rapidly.
When unfavorable conditions stress the organism, sexual reproduction
occurs and the offspring have an increased likehood that they will be better
suited for the environment.
Sexual Reproduction
Known
(Ascomycete’s &
Bisidomycete’s)
Unknown
(Deuteromycete’s)
Higher True Fungi
Septate Mycelium
11. CLASSIFICATION OF FUNGI
Depending on cell morphology, fungi can be divided into 4
classes:
I. Moulds
II. Yeasts
III.Yeast like fungi and
IV.Dimorphic fungi
Based on their sexual spore formation fungi are divided into 4
classes:
I. Zygomycetes
II. Ascomycetes
III.Basidiomycetes
IV.Dueteromycetes (Fungi imperfecti)
13. 1. MOULDS
Fungi which form mycelia are called moulds
or filamentous fungi.
Filaments of fungi are called hyphae.
Diameter is 2-10μm .
The cell walls contain chitin.
Some hyphae may divided by cross sections called
septa
Two types of hyphae: Septate and Non-septate
I. Septate: septa divide the hyphae into distinct,
uninucleate or mulitnucleate cell-like units.
II. Nonseptate/coenocytic: does not contain septa
and appear as long, continuous cells with many
nuclei.
Example: Dermatophytes, Aspergillus,
Penicillium, Mucor, Rhizopus
14.
15. 2. YEASTS
Round, oval or elongated, unicellular
fungi
Reproduce by an asexual process called
budding in which the cell develops a
protuberance which enlarges and
eventually separates from the parent
cell
On culture they form smooth, creamy
colonies
Example: Saccharomyces cerevisae,
Cryptococcus neoformans
16. 2. YEASTS
Contains Granular cytoplasm enclosed in cell wall.
Consist oil globule, vacuole, cytoplasm, glycogen and prominent
nucleus and nucleolus
Cell wall composed of – Chitin, (1-10%) Glucan (main structural
component 50-60%), Lipid-Protein (15-23%)
Glucan and Chitin regulate cell division and cell rigidity
Mode of nutrients- Heterotroph, Organotroph, Saprophytic ,Parasitic
Grow best in acidic environment and can tolerate high sugar
concentration and dry condition
17.
18. 3. YEAST LIKE FUNGI
Unicellular (Rounded or Oval)
The bud remains attached to the mother cell and
elongates, followed by repeated budding, forming
chains of elongated chains known as
pseudohyphae.
Example: Candida albicans
19. 4. DIMORPHIC FUNGI
Mainly pathogenic species exhibit dimorphism i.e. 2 forms of growth
Fungi can grow either as a mould or as a yeast
Mould like forms produce vegetative and aerial mycellium and Yeast like
forms reproduce by budding
Dimorphism is temperature and CO2 dependant.
At 37oC, the fungus grows yeast like and at 25oC it shows mould like growth
Example: Blastomyces dermatitidis , Penicillium marneffei
22. 1. ZYGOMYCETE'S
Fungi having non-septate hyphae, forms endogenous asexual spores
(sporangiospores) contained within a sac like structures called
sporangia.
Also produce sexual spores known as oospores and zygospores.
Example: Mucor, Rhizopus.
Form sexual spores within a sac and are called ascospores.
The sac is called as ascus.
They form septate hyphae.
Include both yeasts and filamentous fungi e.g. Histoplasm, Candida
etc.
2. ASCOMYCETE’S
23.
24. 3. BASIDIOMYCETE'S
Reproduce sexually and form septate hyphae.
These basidiospores are borne at the tip of the
basidium
Example: Cryptococcus neoformans
Also called as Fungi Impefecii or Hyphomycetes.
Consist of group of fungi whose sexual phases have not been
identified and they form septate hyphae and asexual conidia.
Majority of the pathogenic moulds, yeasts, yeasts like fungi and
dimorphic fungi.
Example: Trichophyton, Epidermophyton
4. DEUTEROMYCETE’S
25.
26. REPRODUCTION
Most fungi reproduce both sexually and asexually.
When environmental conditions are favorable, asexual reproduction
occurs rapidly.
When unfavorable conditions stress the organism, sexual reproduction
occurs and the offspring have an increased likehood that they will be
better suited for the environment.
27.
28. VEGETATIVE REPRODUCTION
Production of various types of spores
Fission
Single cell multiply to two new daughter cells.
Rhizomorphs
Hyphae woven to form rope like structure
Under favourable condition, grows into new cell.
Fragmentation
Hyphae dry out and shatter releasing individual cells
that act like spores (athlete’s foot)
Budding
Small offspring
Sclerotia
29.
30. ASEXUAL REPRODUCTION
Production of various types of spores
Sporangiospore
Inside Sporangium Motile Zoospore
(Chyidomycota, Hypochytidomycota, oomycota)
Non-motile Apllanospore
Conidia
Formed at the tip of Supporting Hyphae
Thallic (Septation & Fagmentation)
Blastic (Budding)
31.
32. Arthrospores – formed by segmentation &
condensation of hyphae
Chlamydospores – Thick walled resting spores
developed by rounding up and thickening of hyphal
segments.
THALLIC ASEXUAL REPRODUCTION
33. Blastospores: These are formed by budding from
parent cell, as in yeasts.
BLASTIC ASEXUAL REPRODUCTION
34. SEXUAL REPRODUCTION
Occurs via fusion of gamates and gamatangia
SexualReproduction
Plasmogamy
Karyogamy
Meiosis
35. It is accumulation of protoplast cell of reproductive
hyphae.
Nuclei from one male and one female fused together
forms Zygospore and Spermatia without fusion
(Spematization)
PLASMOGAMY
36. Two parent nuclei are fused together to form new cell.
Known as Dikaryotes
KARYOGAMY
39. GROWTH
Growth is defined as the irreversible increase in the dry
mass of an organism. It is brought about by an increase
in cell size or number.
40. HOW GROWTH TAKES PLACE INFUNGI?
• Mycelial fungi - extension growth of hyphae(tip).
• Unicellular fungi (e.g. yeasts) - increase in individual cell
volume.
• Yeast like fungi grow partly as yeast and partly as
chain of elongated budding cells joined end to end
.
• Moulds or filamentous fungi with multiple cells forming
typically a thread-like mass with many branches grows by
branching and tip elongation
41. OPTIMAL CONDITION FOR GROWTH
• Presence of water: 80–90% of the fungi
is composed of water by mass, and
requires excess water for absorption due
to the evaporation of internally retent
water.
• Presence of oxygen
• Neutral-acidic pH : Optimum pH 5.0
42. Low-medium temperature: ranges between 1 °C and 35 °C,
with optimum growth at 25 °C.
The majority of nutrients must be able to provide carbon,
proteins, vitamins and cases, ions. Due to the carbon composition
of the majority of organisms, dead and organic matter provide
rich sources of disaccharides and polysaccharides such as maltose
and starch and of the monosaccharide glucose.
43. In terms of nitrogen-rich sources, saprotrophs require
combined protein for the creation of proteins, which is
facilitated by the absorption of amino acids, and usually
taken from rich soil. Although both ions and vitamins are
rare, thiamine or ions such as potassium, phosphorus, and
magnesium aid the growth of the mycelium.
44. HOW FUNGI IS GROWN ON LAB?
1. Liquid bath culture
2. Liquid continuous culture
3. Culture on solid media
45. LIQUID BATH CULTURE
If we wanted to
estimate the growth of
a mycelial fungus
growing in a LIQUID
medium, we might
first have to filter off
the liquid medium
and then determine
the dry mass of
the mycelium.
46. LIQUID CONTINUOUS CULTURE
An alternative to the liquid batch
culture system is CONTINUOUS
CULTURE in a liquid medium:
This involves the CONTINUOUS
ADDITION OF FRESH CULTURE
MEDIUM to the vessel and the
WITHDRAWAL (by means of an
overflow devise) of a corresponding
volume of OLD, SPENT MEDIUM,
which will contain some of the
microbial cells.
The apparatus used is called
a chemostat
47. SOLID MEDIA
While it's relatively easy to
determine the biomass of a fungus
growing in a liquid medium, it's
more difficult to estimate biomass
when a fungus is growing in all three
dimensions over and through a solid
medium.
For this reason we usually express
the growth of a colony in terms of
the RADIAL EXTENSION OF THE
COLONY (i.e. we measure colony
radius).
48. NUTRITION IN FUNGI
ALL fungi are CHEMOHETEROTROPHIC (chemo- organotrophic)
- synthesising the organic compounds they need for growth and
energy from pre-existing organic sources in their environment,
using the energy from chemical reactions.
They lack chlorophyll pigments and are incapable of photosynthesis.
Fungi absorb their food, rather than ingesting it as their protoplasm
is surrounded by rigid wall.
SMALL MOLECULES (e.g. simple sugars, amino acids) in solution
can be absorbed directly across the fungal wall and plasma
membrane..
49. LARGER, MORE COMPLEX MOLECULES (e.g. polymers such as
polysaccharides and proteins) must be first broken down into
smaller molecules, which can then be absorbed. This degradation
takes place outside the fungal cell or hypha and is achieved by
enzymes which are either released through or are bound to the
fungal wall. Because these enzymes act outside the cell they are
called extracellular enzymes.
Since water is essential for the diffusion of extracellular
enzymes and nutrients across the fungal wall and plasma
membrane, actively growing fungi are usually restricted to
relatively moist (or humid) environments.
50. Fungi are more resistant to high osmotic pressure
than bacteria.
Fungi require less nitrogen than bacteria to grow and can
grow at PH of 5.
51. PROCESS OF NUTRITIONINTAKE
As matter decomposes within a medium in which a saprotroph is
residing, the saprotroph breaks such matter down into its composites.
Proteins are broken down into their amino acid composites through
the breaking of peptide bonds by proteases.
Lipids are broken down into fatty acids
and glycerol by lipases.
Starch is broken down into pieces of simple disaccharides
by amylases.
52. These products are re-absorbed into the hypha through the
cell wall via endocytosis and passed on throughout the
mycelium complex. This facilitates the passage of such
materials throughout the organism and allows for growth
and, if necessary, repair.