Secondary metabolites of filamentous fungi . While all mycotoxins are of fungal origin, not all toxic compounds produced by fungi are called mycotoxins.

1. G . KISHALINI
Ш B.sc MICROBIOLOGY
PG AND RESEARCH DEPARTMENT OF BIOTECHNOLOGY AND
MICROBIOLOGY
NATIONAL COLLEGE [AUTONOMOUS]
TRICHY- 620001
TAMIL NADU, INDIA

2.  All mycotoxins are low-molecular-weight natural
products (i.e., small molecules) produced as
secondary metabolites by filamentous fungi that are
capable of causing disease and death in humans and
other animals
 While all mycotoxins are of fungal origin, not all
toxic compounds produced by fungi are called
mycotoxins
 It can be heat stable , not destroyed by canning or
other processes

3.  The term mycotoxin was coined in 1962 in the
aftermath of an unusual veterinary crisis near
London, England, during which approximately
100,000 turkey poults died.
 When this mysterious turkey X disease was linked
to a peanut (groundnut) meal contaminated with
secondary metabolites from Aspergillus flavus
(aflatoxins)
 300 to 400 compounds are now recognized as
mycotoxins

4.  Mycotoxins are not only hard to define, they are also challenging to
classify due to diverse chemical structure
 Clinicians often arrange them by the organ they affect thus, mycotoxins
can be classified as hepatotoxins, nephrotoxins, neurotoxins,
immunotoxins
 Cell biologists put them into generic groups such as teratogens,
mutagens, carcinogens, and allergens
 Biochemists according to their biosynthetic origins (polyketides, amino
acid-derived, etc.); physicians by the illnesses they cause (e.g., St.
Anthony's fire, stachybotryotoxicosis), and mycologists by the fungi that
produce them (e.g., Aspergillus toxins, Penicillium toxins).
 None of these classifications is entirely satisfactory.

5. Toxins Producing fungi Toxicities
Aflatoxin Aspergillus flavus Hepatocarcinogen
Aspergillus parasiticus and fatty liver
Citreoviridin Penicillium viridicatum Cardiac beri-beri
Citrinin Penicillium vindicatum Nephrotoxin
Penicillium citrinum
Cyclochlorotine Penicillium islandicum Hepatotoxin
Cytochalasin E Aspergillus clavatus Cytotoxicity
Maltoryzine Aspergillus oryzae
Ochratoxins Aspergillus ochraceus Hepatotoxin
Patulin Penicilliumc-expansum Brain & lung hemmorrhage
Penicillium patulum and carcinogenicity
PR Toxin Penicillium requeforti
Rubratoxin Penicillium rubrum Liver hemmorrhage and
fatty infiltration
Rugulosin Penicillium islandicum Nephrosis & liver damage
Sterigmatocystin Aspergillus flavus Hepatocarcinogen
Aspergillus versicolor
Tremorgens Penicillium and
Aspergillus
Trichothecenes Fusarium graminearum Cytotoxicity
Vomitoxin
(Deoxynivalenol)
Fusarium graminearum Vomiting
Zearalenone Fusarium Hyper-estrogenic effect
Table: Some mycotoxins, their sources and potential toxicities.

6. Alfatoxins
Fumonisin
Ochratoxins
Patulin
Citrinin
Trichothecenes
Zearalenone

7. Aflatoxins are various poisonous
carcinogens and mutagens that are
produced by certain molds, particularly
Aspergillus species.
The fungi grow in soil, decaying
vegetation and various staple foodstuffs
and commodities such as hay,
sweetcorn, wheat, millet, , chili
peppers, cottonseed, peanuts, tree
nuts, sesame seeds, sunflower seeds,
and various spices

8.  Patulin is a toxin produced by the P. expansum,
Aspergillus, Penicillium, and Paecilomyces fungal
species. P. expansum is especially associated with a
range of moldy fruits and vegetables, in particular
rotting apples and figs.
 It is destroyed by the fermentation process and so is
not found in apple beverages, such as cider

9.  Mycotoxins have the potential for both acute
and chronic health effects via
 ingestion
 skin contact
 inhalation and
 entering the blood stream and lymphatic
system
 inhibit protein synthesis,
 damage macrophage systems,
 inhibit particle clearance of the lung,
 increase sensitivity to bacterial endotoxin

10.  development of fungal resistant varieties of
growing plants;
 making schedule for suitable pre-harvest,
harvest and post-harvest
 Using fungicides and preservatives against
fungal growth