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Learning objectives

  • Explain why the study of fungi such as yeast and molds is within the discipline of microbiology
  • Describe the unique characteristics of fungi
  • Describe examples of asexual and sexual reproduction of fungi
  • Compare the major groups of fungi in this chapter, and give examples of each
  • Identify examples of the primary causes of infections due to yeasts and molds
  • Identify examples of toxin-producing fungi
  • Classify fungal organisms according to major groups

The fungi comprise a diverse group of organisms that are heterotrophic and typically saprozoic. In addition to the well-known macroscopic fungi (such as mushrooms and molds), many unicellular yeasts and spores of macroscopic fungi are microscopic. For this reason, fungi are included within the field of microbiology.

Fungi are important to humans in a variety of ways. Both microscopic and macroscopic fungi have medical relevance, with some pathogenic species that can cause mycoses (illnesses caused by fungi). Some pathogenic fungi are opportunistic, meaning that they mainly cause infections when the host’s immune defenses are compromised and do not normally cause illness in healthy individuals. Fungi are important in other ways. They act as decomposers in the environment, and they are critical for the production of certain foods such as cheeses. Fungi are also major sources of antibiotics, such as penicillin from the fungus Penicillium .

Characteristics of fungi

Fungi have well-defined characteristics that set them apart from other organisms. Most multicellular fungal bodies, commonly called molds , are made up of filaments called hyphae . Hyphae can form a tangled network called a mycelium and form the thallus (body) of fleshy fungi. Hyphae that have walls between the cells are called septate hyphae ; hyphae that lack walls and cell membranes between the cells are called nonseptate or coenocytic hyphae ). ( [link] ).

Molds can have septate hyphae - long strands with cell walls separating the nuclei. Or they can have coenocytic (nonseptate) hyphae - long strands with no cell wall separating the nuclei. Or they can have pseudohyphae which look like chains of cells with small clusters at intervals
Multicellular fungi (molds) form hyphae, which may be septate or nonseptate. Unicellular fungi (yeasts) cells form pseudohyphae from individual yeast cells.

In contrast to molds, yeasts are unicellular fungi. The budding yeasts reproduce asexually by budding off a smaller daughter cell; the resulting cells may sometimes stick together as a short chain or pseudohypha ( [link] ). Candida albicans is a common yeast that forms pseudohyphae; it is associated with various infections in humans, including vaginal yeast infections, oral thrush, and candidiasis of the skin.

Some fungi are dimorphic, having more than one appearance during their life cycle. These dimorphic fungi may be able to appear as yeasts or molds, which can be important for infectivity. They are capable of changing their appearance in response to environmental changes such as nutrient availability or fluctuations in temperature, growing as a mold, for example, at 25 °C (77 °F), and as yeast cells at 37 °C (98.6 °F). This ability helps dimorphic fungi to survive in diverse environments. Histoplasma capsulatum , the pathogen that causes histoplasmosis , a lung infection, is an example of a dimorphic fungus ( [link] ).

Questions & Answers

Who invented microbes?
manor Reply
Which year did Robert koch invented the microbes?
manor
Robert Koch
Matilda
Antony Van Leeuwenhoek invented microbes through a designed single lensed microscope.
Mohamed
what is microbiology
Nyoik Reply
microbiology is the study of micro organisms. this can be multicellular,unicellular & acellular
Janet
what is the difference between DNA/RNA
kanaaLka
DNA is a double stranded molecule while RNA is a single stranded molecule
Lovely
who is the inventor of microscope
Alberta
What are antibodies?
Happy Reply
they are immune cells that are released by immune system to fight strangers like microbes
Ahmed
a blood protien produce in response to an counteracting a specific antigen
Pooja
Why salmonella typhi is harmful protozoan?
Saily Reply
because make typhoid that is considered as a food born illness
Ahmed
Name any five modes of transmission.
Happy
what are the scientific names and common names of some microbes
Rich Reply
Staphylococcus aureus - staph Streptococcus pyogenes - strep Botulism - Clostridium botulinum Rocky Mountain spotted fever - Rickettsia rickettsii Diphtheria - Corynebacterium diphtheriae Gonorrhea - Neisseria gonorrhoeae
Tammy
what are the limitations of the Koch's postulate
Naa
how a microorganism growth.
Zubair Reply
Is foetus a parasite to his or her mother? if yes and if no ho
Mashauri Reply
y
Yusri
yes
Yashkin
yes
Zubair
yes it a parasite to the mother because it feeds on the mother for survival
Beatrice
yes
Redwan
no
Elasha
definition of a parasite: an organism that lives in or on an organism of ANOTHER species (its host) and benefits by deriving nutrients at the other's expense
Elasha
no because an organism can inky be a parasite if it causes harm to its HOST. And the fetus does not cause harm to its mother under normal conditions
aliyu
yes
Naa
what is biosensor in microbiology
Raja Reply
What are biosensor
Raja
what's are biosensor
Raja
what is microbiology defination
Rinku Reply
microbiology is the study of small or manuit organisms which cannot be seen with our nacked eyes unless with the aid of the microscope
Brandina
is the study of living organisms which are not directly visible to a direct eye but can only be seen under a microscope
Ipa
ok
Ipa
microbiology is the study of living organisms of microscopic size it is also the study of micro organisms with their form structure reproduction psychology metabolism and classification
Priyanka
ok
Aminu
Microbiology are the study of microorganisms either microscopic or sub microscopic creaters mainly unicellulars, multicellulars and subcellulars. Such as protozoa,bacteria and viruses.
Rana
it is the biological study of viruses, fungi, protozoa, bacteria which in collective name are called micro organisms, unlike microscopic organisms being invisible, that requires a magnifications with the help of a microscope.
Mohamed
what are the importances of Microbiology?
Erick Reply
don't know
SINGLE
we obtained the insulin from the bacteria. and some microorganisms are decomposer in ecosystems.
Zubair
nitrogen in the air is fixed into the soil by microbes example is nitrobactor
Matilda
yes
Zubair
how a weak immune region where microorganisms attack easily?
Zubair Reply
with examples differentiate gram positive from gram negative bacteria
Mary Reply
Differentiate gram positive from gram negative
Mary
I have no idea
Zubair
hello
Kuonain
and example of gram negative is E. coli
Pooja
gram positive stain purple when subjected to gram stain whilst gram positive bacterial has thick wall composed of peptidoglycan
Matilda
ok
Zubair
what is a process of gene expression in eukaryotes ?
Nayyab Reply
pls help us with the answer
Abdussalam
spontaneous generation means
Siddhi Reply
hiii
Siddhi
Hello
eman
So, what's next 😂
eman
I have a problem with Micro
eman
I studying things and see question Some thing else
eman
Can u help me, please
eman
What i havta do
eman
firsfall when you studying understand things...
Siddhi
good afternoon dear Friends
yaya
Greeting to everyone in here.
Manka
There is a problem. I need a diagram of a virus with it functions.
Manka
structure of bacterial
Kuyiba
gghhhh
Zubair
group plz i need help in microbio
Kuonain
it really difficult fr me
Kuonain
kashur cha kah
suhail
sorry now I read in class 8th but I can help u
Zubair
Me too. It's very difficult for me
Angela
rod shape
Priyanka
helical
Priyanka
Hello
esike
spherical
Priyanka
peomorphic
Priyanka
I am ryt or not
Priyanka
hi
suhail
hello
DIPTI
Are we together pls what's the topic for the day?
esike
what is innate
Lizzy
innate means natural
Pooja
the genetic makeup of an individual
Matilda
pls i need the common names for the following parasites..ENTEROBIUS VERMICULARIS,NECATOR AMERICANUS,ASCARIES LUMBRICOIDES,TRICHURIS TRICHIURA,TRICHOMONAS VAGINALIS,GIARDIA LAMBLIA,ENTAMOEBA HISTOLYTICA,SCHISTOSOMA MANSONI,SCHISTOSOMAHEMATOBIUM,STROGYLOIDES STERCORALIS,AND TRAPANOSOMA BRUCI GAMBIENSE
timothy
ENTEROBIUS VERMICULARIS and STROGYLOIDES STERCORALIS have the same common name which is pin worm and thread worm
Chinedu
I didn't find the common names for TRICHOMONAS VAGINALIS, GIARDIA LAMBLIA, ENTAMOEBA HISTOLYTICA, TRYPANOSOMA BRUCEI GAMBIENSE
Chinedu
NECATOR AMERICANUS - New world hookworm ASCARIS LUMBRICOIDES- Ascarid TRICHURIS TRICHIURA- Whip worm
Chinedu
Hi guys
Chinedu
Why are myeloblasts not present in the bloodstream?
Chinedu
thank u
Dasaah
is blood from capillary puncture suitable for hormonal assays
NANCY Reply
Direct this question to a hematologist for a better answer please.
LAFIA
In most cases the blood is necessary but it's limited from my own Analysis
Lee
u can do but it depends on your sampling blood its enev or not
Ali

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Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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