Secondary metabolites produced by fungi

1. 1

2. • Some mycotoxins could also be toxic to plants or other
microorganisms but these compounds are not classified
as antibiotics of fungal origin.
of mycotoxins for the fungi themselves is still not clearly
defined. 2
• Mycotoxin is a convenient generic term describing the
toxic secondary metabolites produced by fungi. “Myco”
means fungal (mold) and “toxin” represents poison.
• Like most microbial secondary metabolites, the benefit
• They encompass a considerable variety of low molecular
weight compounds with diverse chemical structures and
biological activities.

3. • In considering the effects of mycotoxins on animals
it is important to distinguish between “mycotoxicosis”
and “mycosis.”
• Mycotoxicosis is used to describe the action of
mycotoxin and is frequently mediated through a
number of organs, notably the liver, kidney, lungs, and
the nervous, endocrine, and immune systems.
• Mycosis refers to a generalized invasion of living
tissue by growing fungi.
3

4. MAJOR GROUP
• Aflatoxins
• Ochratoxine
• Citriniergot alkaloid
• Patuline
• Fusarium
4

5. • Type of mycotoxin produced by Asprgillus species of
fungi.
• The most toxic, is a potent carcinogen and has been
directly correlated to adverse health effects, such
as liver cancer, in many animal species.
• Aflatoxins are largely associated with commodities
produced in the tropics and subtropics such
as cotton, peanuts, spices, pistachios, and maize.
Ex- Aspergillus flavus and Aspergillus parasiticus
5

6. • Mycotoxin that comes in three secondary metabolite
forms, A, B, and C.
• All are produced by Penicillium and Aspergillus species.
• Found as a contaminant of a wide range of commodities
including beverages such as beer and wine.
• Ochratoxine A has been labeled as a carcinogen and a
nephrotoxin, and has been linked to tumors in the human
urinary tract, although research in humans is limited
by confounding factors.
Ex- Aspergillus ochraceus , Aspergillus carbonarius.
6

7. • Toxin that was first isolated from Penicillium citrinum,
but has been identified in over a dozen species
of Penicillium and several species of Aspergillus.
• Some of these species are used to produce human food
such as cheese , sake, miso, and soy sauce.
• Citrinin is associated with yellowed rice disease in
Japan and acts as a nephrotoxin in all animal species
tested.
• Although it is associated with many human foods . its
full significance for human health is unknown.
Ex-Penicillium camemberti, Aspergillus oryzae. 7

8. • Compounds produced as a toxic mixture of alkaloids in
the sclerotia of species of claviceps, which are common
pathogens of various grass species.
• The ingestion of ergot sclerotia from infected cereals,
commonly in the form of bread produced from
contaminated flour, cause ergotism
• The human disease historically known as st. Anthony's
fire.
8

9. • Toxin produced by the aspergillus, penicillium,
and paecilomyces fungal species. It is destroyed by
the fermentation process.
• Although patulin has not been shown to be carcinogenic,
it has been reported to damage the immune system in
animals.
• Ex-penicillum expansum is especially associated with a
range of moldy fruits and vegetables.
•
9

10. • Ex-
• Zearalenone-which is not correlated to any
fatal toxic effects in animals or humans.
10
• Toxins are produced by over 50 species
of Fusarium and have a history of infecting the
grain of developing cereals such
as wheat and maize.
• Fumonisins- which affect the nervous
systems of horses and may cause cancer
in rodents
• Trichothecenes- which are most
strongly
associated with chronic and fatal
toxic
effects in animals and humans

11. • Invasion by fungi and production of mycotoxins in
commodities can occur under favorable conditions in the
field, at harvest, and during processing, transportation
and storage.
 Fungi that are frequently found in the field include: A.
flavus, Alternaria
longipes, A. alternata, Claviceps purpura, Fusarium verticillioides
(previously called moniliforme), F. graminearum, and a number of
other Fusarium spp.
 Species most likely introduced at harvest include:
F. sporotrichioides, Stachybotrys atra, Cladosporium sp.,
Myrothecium verrucaria, Trichothecium roseum, as well as A.
alternata.
11
Pta jise like Kiya jata use btaya nh

12.  Most penicillia are storage fungi. These include:
Penicillium citrinum, P. cyclopium, P. citreoviride, P.
islandicum, P. rubrum, P. viridicatum, P. urticae, P.
verruculosum, P. palitans, P. puberulum, P. expansum, and P.
roqueforti.
All of which are capable of producing mycotoxins in
grains and foods
12

13. • The most obvious negative economic impact of mycotoxins
is an outright loss of crops and affected animals.
• Also, humans may encounter severe health hazard or high
mortality rates in countries with less regulate.
• Livestock industry some time fully fallen down because of
mycotoxine which produce harmful fungi.
• Large scale crop production also faced mycotoxine
problem, they need to apply fungicides that directly
effect their profit.
13

14. 14

15. • Mycotoxin is a convenient generic term describing the
toxic secondary metabolites produced by fungi.
• There are 6 major group belongs to mycotoxcine
• Not all the fungi produce harmful micotoxine some
are produce beneficial toxin example penicillium
notatum which use as antibiotic.
15
• mycotoxine is magior .problem in agriculture,there
many way now introduce prevent those mycotoxine
problems.

16. 16