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Fungi

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SECOND SEMESTER 2020/2021 SESSION
GROUP WORK ASSIGNMENT
COURSE CODE: MCB212
SUPERVIED BY:
PROF. MR. AMARE
QUESTION:
DISCUSS THE CLASSIFICATION OF FUNGI WITH THERE BENEFIT
THE DEPARTMENT OF MICROBIOLOGY,
FACULTY OF LIFE SCIENCES,
AMBROSE ALLI UNIVERSITY,
EKPOMA, EDO STATE.
FEBRUARY,2022.
1
ACKNOWLEDGEMENT
Group Leader: AWORUNSE KEHINDE GLORIA FLS/MCB/19/53762 E1106192
Asst. Group Leader: PAULINUS PROSPER UDO FLS/MCB/19/55778 E1103702
GROUP MEMBERS
Names of Students
OBAZE PERPETUAL IVIE
EDORE SCHOLASTICA .O.
FRANK MERCY OKHUELA
Matriculation
Number
FLS/MCB/19/50647
FLS/MCB/19/59276
FLS/MCB/19/59276
FLS/MCB/19/51414
FLS/MCB/19/52167
FLS/MCB/19/56419
FLS/MCB/19/54809
E1102175
E1112675
E1111680
E1105149
E1102462
E1125081
E1106563
ONOWU ANTHONIA CHIMDUWU
OFULU IFEOMA FAVOUR
FLS/MCB/19/55731
FLS/MCB/19/58889
E1103948
E1107422
IFUEKO AIYEVBOSA
IBEH SOPHIA CHIWENDU
ODUTOLA HALLELUYA OLUWATOYIN
EVBODAGHE OMONO JENNIFER
OGETTE EDNA
OKORO JOY
ONI ODION DIVINE
UWAIFO VICTOR
FLS/MCB/19/51728
FLS/MCB/19/55041
FLS/MCB/19/59631
FLS/MCB/19/51482
FLS/MCB/19/51239
FLS/MCB/19/52467
FLS/MCB/19/58271
FLS/MCB/19/55731
FLS/MCB/19/50696
E1114145
E1106174
E1100449
E1113948
E1106419
E1105341
E1106955
E1103948
E1112845
OGBEREYIVWE NELLY
FLS/MCB/19/54639
E1105280
ILONTUMHAN OSARUGUE SHELTER
FAYEFUMMI OLUWAFEMI
ELEFAN DANIEL
ENOMAYO OGHONOMWENAKHIN SONIA
ADETUNJI RACHEAL OLUWAFUNMILAYO
2
Student ID.
FUNGI
What is a Fungi?
Fungi are Eukaryotic, Spore bearing organism that has absorptive
nutrition and lacks chlorophyll; reproduces Asexually and Sexually or both
and normally has cell wall called Chitin.
Fungi are important decomposers that break down organic matter; live
as parasite on animals, humans, and plants; Fungi secrete enzymes outside
their body structure and adsorbs the digested food. that include
microorganism such as Yeasts, Moulds and Mushroooms e.t.c.
CLASSIFICATION OF FUNGI
Fungi, can be classified based on their different bases:
A. CLASSIFICATION OF FUNGI BASED ON THEIR MODE OF NUTRITION
On the basis of nutrition, Kingdom Fungi can be classified into 3 groups
Saprophytic:
The fungi obtain their nutrition by feeding on dead organic
substances E.g Rhizopus, Penicillin, and Aspergillus.
Parasitic:
The Fungi obtain their nutrition, by living on other living
organism (Plant or Animals) and absorbs nutrients from their host E.g
Taphrina and Puccinia.
Symbiotic:
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These fungi live by having an interpedently relationship
association with other species in which both are mutually benefit. E.g
Liches and Mycorrhiza.
B. CLASSIFICATION OF FUNGI BASED ON THEIR
TAXONOMICAL SYSTEMATIC .
Zygomycota:
These are formed by the fussion of two different cells. The sexual
spores are known as Zygospore, while the asexual spores are known as
Sporangiospore. The hypae are without the septa e.g Rhizopus, Absida,
Mucor.
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Rhizopus stolorifer, a Zygomycete that Grows on SimpleSugars.
The fungus is often found on moist bread or fruit. Zygomycete is named
for the zygosporangia characteristic of members of `the genus Rhizopus
Ascomycota:
They are also called Sac-Fungi they can be co-prophilous
decomposers, Parasitic or Saprophytic Ascomycetes. Produces sexual
spores called ascosphores, formed in Sac-like Structure called asci, and
also small asexual spores called Conidia the hypae are narrow septate.
E.g Penicillin, Yeasts, Aspergillus, Morels, Neurospora and Truffels.
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The Typical Life Cycle of a Filamentous Ascomycete
Basidomycota:
They are also called Club Fungi This class includes common
Mushrooms and Shelf fungi Sexual reproduction involve in the
formation of Basidium (Basidiospores) Asexual reproduction can be
either budding or asexual spore formation, or by fragmentation. Asexual
Spore formation, however most often takes places at the end of
specialized structures called Conidiophores. Hypae is divided by Septa.
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Basidiomycota: The life Cycle of a Typical Soil Basidiomycetes
Deuteromycota:
They are otherwise called imperfect fungi (Anmorph) as they do
not follow the regular reproduction cycles as the other fungi they do not
reproduce Sexually. Asexual reproduction occurs by Conidia,
they
form Septate hypae E.g Coccidiodae, Immitis, Paracoccidiodies,
Brasitiensis, Candida Albicon, e.t.c
C. CLASSIFICATION OF FUNGI BASED ON THEIR USES
1. Some Fungi hels in recycling dead Organic matter. They are Sapotrophs
e.g Rhizopus.
2. They Serve as Food E.g Mushrooms.
3. Medicines/Penicillin antibiotics is derived from a common Fungi
Penicillium.
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4. Bio-control agents, Fungi are involved in exploiting insects, other small
worms and help in controlling pest E.g Trichoderma, Alternaria,
Verticillium, Aspergillius. Candida Fusarium e.t.c
5. Some Fungi causes food Spoilage e.g Yeasts and Molds
6. Some serves for enhancing food quality and quantity, e.g Yeasts.
D. Classification of Fungi by Morphological Features
According to cruickshant et al, (1973) morphologically fungi can be
categlorized into four(4) main groups:
THE MOULDS
They grow into long filamentous from (hypae) which branch and into a
mesh work, the mycelium. They reproduce by the formation of various kinds
of Spores such as Sporangiospore in Rhizopus spp, Mucor spp, and Condida
form. common genera of moulds include: Acremonium. Alternaria,
Aspergillus,
Cladosporium,
Fusarium,
Mucor,
Penicillium,
Rhizopus,
Stachybotrys, Trichoderma and Trichophyton.
THE YEASTS
The Yeasts are Unicellular Fungi they reproduce by budding, they differ
from most fungi which grows as thread like hypae the common baker’s yeast
Saccharomyes Cerevisiae. The genus Cryptococcus, which includes C.
Neoformans, a pathogen of Human.
THE YEAST-LIKE FUNGI
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These are similar to the yeast in growing by forming blastospore. The
blastospore here can grow into a group of flamentous cells joined end to end
called Psuedohypae or Psuedomycellium example Candida alblcans.
DIMORPHIC FUNGI
Dimorphic means two (2) morphological forms they groups other in
hypae or Yeast according to the conditions of occurance. Growth usually takes
place in the hypae mycelial form as saprophytes and in the yeast form as
parasitic in animal body examples includes: Histoplasma, Capsulatum,
Blastomyces dermatitidis.
E. CLASSIFICATION BASED ON PATHOGENIC NATURE
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Based on the pathogenic potential, Fungi may be considered as:
1. PRIMARILY PATHOGENIC:
Those Fungi which are able to cause infections in healthy
individuals for example, thermally dimorphic Fungi
2. OPPORTUNISTIC PATHOGENS:
Those Fungi that are able to cause infections in patients who are
immuno- compromised due to some other infections or diseases or who
are receiving immuno-suppresive drugs E.g Aspergillus Flavus.
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CLASSIFICATION OF FUNGI BASED SPORE PRODUCTION
On the basis of the organisation of the vegetative thallus, the
morphology of reproductive structures, the way of spores production and
particular life cycle involved the kingdom mycota is classified into following
divisions.
Phycomycetes
• It includes the simplest type of fungi. It is also called as Algae-Fungi because
most of the characteristics of them are similar to algae like Vaucheria.
• They have simple thallus which is unicellular or coenocytic or aseptate
filaments.
• They reproduce asexually by the formation of zoospores or non-motile
spores.
• Sexual reproduction is isogamous or heterogamous which takes place by
gametangial contact.
• The diploid phase is represented by zygote.
• Phycomycetes has been classified into subclasses:
(a)oomycetes and( b) zygomycetes.
Oomycetes
• Oomycetes range from a primitive unicellular thallus to a profusely
branched filamentous mycelium.
• Many members of them are terrestrial and obligate parasites.
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• Asexually they reproduce by biflagellate zoospores.
• Sexual reproduction is oogamy that involves the fusion of male and female
gametes to form oospore.
• Oospore undergoes meioses to produce haploid biflagellate zoospores.
• Example; Phytophthora infestans(causes potato blight)
Zygomycetes
• The group is named zygomycetes because a diploid resting spore called the
zygospore is formed during the life cycle.
• They are mostly saprophytic, some others are parasites on plants and
animals.
• The vegetative body is mycelium which is well developed, profusely
branched and coenocytic.
• The absence of motile sexual or asexual cells.
• The asexual reproduction takes place by sporangiospores, aplanospores or
by conidia.
• Sexual reproduction occurs by conjugation of gametangia resulting in the
formation of zygospore.
• Examples; Rhizopus, Mucor etc
ASCOMYCETES:
The species of ascomycetes are called the sac fungi because they
produce sexual pores within the sac-like vascus.
General Characteristics
• Ascomycetes are mostly terrestrial occurring as saprophytes or parasites.
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• They have well-developed, branched, septate mycelium except yeast. Yeast
is a unicellular fungus.
• Asexually they reproduce by non-motile spores, conidia, oidia or
chlamydospores.
• Sexual reproduction takes place by the fusion of gametangia of opposite
mating types.
• There is absence of motile cells.
• Examples, Saccharomyces cerevisiae, Penicillium, Aspergillus etc.
BASIDIOMYCETES:
• The members of basidiomycetes are saprophytic or parasitic. The group is
named basidiomycetes as they produce the basidiospores at the club-shaped
basidium during sexual reproduction.
• Mycelium is highly developed, profusely branched and septate.
• The mycelia are differentiated into two mating types; (+ve) and (-ve).
• There are two kinds of mycelium; primary mycelium and secondary
mycelium.
• Asexual reproduction takes place by fragmentation, budding, oidia, conidia
or chlamydospore.
• The dikaryotic cell is formed during sexual reproduction.
• The absence of motile cell throughout the life cycle.
• Basidiomycetes are the most advanced fungi as their fructifications are often
large and prominent.
• Examples; Mushrooms, Puccinia, Ustilago etc.
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DEUTEROMYCETES (The Imperfect Fungi)
• Deuteromycetes compromises more than 17000 species of the diverse
habits and habitats. It is considered as an artificial class of fungi.
• The fungi are saprophytes as well as parasites. Parasitic fungi cause serious
diseases to plants, animals including human beings.
• Some of them are unicellular while others are multicellular.
• They reproduce asexually by conidia along with some other types of spores.
• The sexual reproduction is entirely absent.
• The asexual stage or imperfect stage in Deuteromycetes is well defined. But
the sexual or perfect stage is absent in life cycle, therefore, they are called
‘Fungi Imperfecti’.
• Example; Alternaria, Fusarium, Helminthosporium etc.
F. CLASSIFICATION BASED ON VIRULENCE
Primarily
Pathogen
can
establish
infection
on
normal
host,
Opportunistic Pathogens causes disease in individual with compromised host
defense mechanisms.
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The Primarily Systematic Fungal Pathogens include Coccidiodes
immitis,
Histoplasma,
Capsulatum,
Blastomyces,
Dermatitidis,
and
Paracoccidioides brasiliiensis.
The Opportunistic Fungal Pathogens include: Crytococcus neoforman,
Candida,
Aspergillus
spp,
Penicillium
marneffei,
the
Zygomycetes,
Trichosporon beigeli and Fusarium spp.
BENEFIT OF FUNGI
Human have been indirectly aware of fungi since the Humans have been
indirectly aware of fungi since the first loaf of leavened bread was baked and
the first tub of grape must was turned into wine. Ancient peoples were
familiar with the ravages of fungi in agriculture but attributed these diseases
to the wrath of the gods. The Romans designated a particular deity, Robigus,
as the god of rust and, in an effort to appease him, organized an annual
festival, the Robigalia, in his honour.
Fungi are everywhere in very large numbers—in the soil and the air, in
lakes, rivers, and seas, on and within plants and animals, in food and clothing,
and in the human body. Together with bacteria, fungi are responsible for
breaking down organic matter and releasing carbon, oxygen, nitrogen, and
phosphorus into the soil and the atmosphere. Fungi are essential to many
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household and industrial processes, notably the making of bread, wine, beer,
and certain cheeses. Fungi are also used as food; for example, some
mushrooms, morels, and truffles are epicurean delicacies, and mycoproteins
(fungal proteins), derived from the mycelia of certain species of fungi, are
used to make foods that are high in protein.
Studies of fungi have greatly contributed to the accumulation of
fundamental knowledge in biology. For example, studies of ordinary baker’s
or brewer’s yeast (Saccharomyces cerevisiae) led to discoveries of basic
cellular biochemistry and metabolism. Some of these pioneering discoveries
were made at the end of the 19th century and continued during the first half
of the 20th century. From 1920 through the 1940s, geneticists and
biochemists who studied mutants of the red bread mold, Neurospora,
established the one-gene–one-enzyme theory, thus contributing to the
foundation of modern genetics. Fungi continue to be useful for studying cell
and molecular biology, genetic engineering, and other basic disciplines of
biology.
The medical relevance of fungi was discovered in 1928, when Scottish
bacteriologist Alexander Fleming noticed the green mold Penicillium notatum
growing in a culture dish of Staphylococcus bacteria. Around the spot of mold
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was a clear ring in which no bacteria grew. Fleming successfully isolated the
substance from the mold that inhibited the growth of bacteria. In 1929 he
published a scientific report announcing the discovery of penicillin, the first of
a series of antibiotics—many of them derived from fungi—that have
revolutionized medical practice.
Another medically important fungus is Claviceps purpurea, which is
commonly called ergot and causes a plant disease of the same name. The
disease is characterized by a growth that develops on grasses, especially on
rye. Ergot is a source of several chemicals used in drugs that induce labour in
pregnant women and that control hemorrhage after birth. Ergot is also the
source of lysergic acid, the active principle of the psychedelic drug lysergic
acid diethylamide (LSD). Other species of fungi contain chemicals that are
extracted and used to produce drugs known as statins, which control
cholesterol levels and ward off coronary heart disease. Fungi are also used in
the production of a number of organic acids, enzymes, and vitamins.
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REFERENCES
1. Horowitz- Brown, S., et al. 2018. Morphological transitions governed by
density dependence and lipoxygenase activity inAspergillus Flavus.
Appl. Environ. Microbiol. 74:5674
2. Carris, L. M., C. R. Little and C. M. Stilies. 2012. Introduction to Fungi.
3. David Hibbett et al. Mycologia. Nov/Dec 2016
4. Mary
E
Brandt.David
W.
Warnock.
Manual
of
Clinical
Microbiology(pp.1932-1943). May 2015
5. Dr. Tanuja, University Department of Botany, Patliputra University
6. Cruickshank, R, et al. Medical Microbiology. 1975
7. Lichtwardt RW, et al. Mycologia. 2011
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