2. Penicillium is a saprophytic fungus, com-monly known
as blue or green mold.
Genus includes approx. 1 36 species, distributed
throughout the world.
They are present in soil, in air, on decaying fruits,
vegetables, meat, etc.
Penicillium fungi are microscopic organisms that are
used in the production of foods and in the
pharmaceutical industry.
3. The “wonder drug” penicillin was first dis-covered by
Sir Alexander Fleming in 1928; during his work with
Staphylococcus aureus , get contaminated with mold
spore (Penicillium notatum) which after proper growth
causes death of S. aureus showing lytic zone around
itself.
He isolated and called this anti-microbial compound as
Penicillin. Later it was found that a strain of P.
chrysogenum,is more efficient than P. notatum, in the
production of penicillin.
6. Penicillium chrysogenum
Penicillium citrinum
Penicillium janthinellum
Penicillium marneffei
Penicillium purpurogenum
Identification to species level is based on macroscopic
morphology and microscopic features
7.
8. The vegetative body is mycelial
The mycelium is profusely branched with septate
hyphae, composed of thin-walled cells containing one
to many nuclei
Each septum has a central pore, through which
cyto-plasmic continuity is maintained.
The reserve food is present in the form of oil globules.
9.
10. Penicillium reproduces by vegetative, asexual and
sexual means.
Vegetative reproduction:
It takes place by accidental breaking of vegetative
mycelium into two or more fragments. Each fragment
then grows individually like the mother mycelium.
11. Asexual repro-duction takes place by unicellular,
uninucleate, nonmotile spores, the conidia; formed on
conidiophore
The conidiophore develops as an erect branch from any
cell of the vegetative mycelium.
The branch of the conidiophore is known as ramus
(plural rami) which further becomes branched known
as metulae. A number of flask-shaped phialid or
sterigmata develops at the tip of each metulae.
Each sterigmata develops at its tip a number of conidia
12. During the development of conidium, the tip of the
sterigma swells up and its nucleus divides mitotically
into two nuclei, of which one migrates into the swollen
tip and by partition wall the swollen region cuts off
from the mother and forms the uninucleate conidium.
The tip of the sterigma swells up again and following
the same procedure second conidium is formed, which
pushes the first one towards the outer side. This process
repeats several times and thus a chain of conidia is
formed.
13.
14. The conidia are oval, elliptical or globose in structure
having smooth, rough, and of various colou-rations like
green, yellow, blue etc.
After maturation, the conidia get detached from the
mother and are dispersed by wind.
On suitable substratum, they germinate by developing
germ tube.
15. By means of Ascospores
The ascospores are released by the dis-solution of ascus
and cleistothecium wall. The ascospore germinates on a
suitable substratum by developing germ tube and
ulti-mately into a mycelium like the mother.
16.
17.
18. 1. The conidiophore in Aspergillus is unseptate and
unbranched. It arises from a specialized, T-shaped
thick-walled foot cell. In Penicillium it is long,
slender, septate and branched. It arises from any
vegetative cell of the mycelium. There are no foot
cells.
2. In Aspergillus the conidiophores enlarge into a vesicle
at its tip which bears the finger-like sterigmata. The
whole structure has the form of a spherical head. The
conidiophore in Penicillium ends in a whorl of
branches which give it a broom-like appearance.
19.
20. Penicillium spp. are occasional causes of infection in
humans
resulting disease is known as penicilliosis.
Penicillium has been isolated from patients with keratitis ,
endophtalmitis, otomycosis, necrotizing esophagitis,
pneumonia, endocarditis, peritonitis, and urinary tract
infections.
Most Penicillium infections are encountered in
immunosuppressed hosts.
In addition to its infectious potential, Penicillium
verrucosum produces a mycotoxin, ochratoxin A, which is
nephrotoxic and carcinogenic. The production of the toxin
usually occurs in cereal grains at cold climates
