Penicillium

Penicillium morphology, reproduction

1. Dr. PoonamShakya

2. Penicilliumisasaprophyticfungus,com­monlyknown
asblueorgreenmold.
Genusincludesapprox.136species,distributed
throughouttheworld.
Theyarepresentinsoil,inair,ondecayingfruits,
vegetables,meat,etc.
Penicilliumfungiaremicroscopicorganismsthatare
usedintheproductionoffoodsandinthe
pharmaceuticalindustry.

3. The“wonderdrug”penicillinwasfirstdis­coveredby
SirAlexanderFlemingin1928;duringhisworkwith
Staphylococcusaureus,getcontaminatedwithmold
spore(Penicilliumnotatum)whichafterpropergrowth
causesdeathofS.aureusshowinglyticzonearound
itself.
Heisolatedandcalledthisanti­microbialcompoundas
Penicillin.LateritwasfoundthatastrainofP.
chrysogenum,ismoreefficientthanP.notatum,inthe
productionofpenicillin.

5. Kingdom:Fungi
Phylum:Ascomycota
Class:Euascomycetes
Order:Eurotiales
Family:Trichomaceae
Genus:Penicillium

6. Penicilliumchrysogenum
Penicilliumcitrinum
Penicilliumjanthinellum
Penicilliummarneffei
Penicilliumpurpurogenum
Identificationtospecieslevelisbasedonmacroscopic
morphologyandmicroscopicfeatures

8. Thevegetativebodyismycelial
Themyceliumisprofuselybranchedwithseptate
hyphae,composedofthin-walledcellscontainingone
tomanynuclei
Eachseptumhasacentralpore,throughwhich
cyto­plasmiccontinuityismaintained.
Thereservefoodispresentintheformofoilglobules.

10. Penicilliumreproducesbyvegetative,asexualand
sexualmeans.
Vegetativereproduction:
Ittakesplacebyaccidentalbreakingofvegetative
myceliumintotwoormorefragments.Eachfragment
thengrowsindividuallylikethemothermycelium.

11. Asexualrepro­ductiontakesplacebyunicellular,
uninucleate,nonmotilespores,theconidia;formedon
conidiophore
Theconidiophoredevelopsasanerectbranchfromany
cellofthevegetativemycelium.
Thebranchoftheconidiophoreisknownasramus
(pluralrami)whichfurtherbecomesbranchedknown
asmetulae.Anumberofflask-shapedphialidor
sterigmatadevelopsatthetipofeachmetulae.
Eachsterigmatadevelopsatitstipanumberofconidia

12. Duringthedevelopmentofconidium,thetipofthe
sterigmaswellsupanditsnucleusdividesmitotically
intotwonuclei,ofwhichonemigratesintotheswollen
tipandbypartitionwalltheswollenregioncutsoff
fromthemotherandformstheuninucleateconidium.
Thetipofthesterigmaswellsupagainandfollowing
thesameproceduresecondconidiumisformed,which
pushesthefirstonetowardstheouterside.Thisprocess
repeatsseveraltimesandthusachainofconidiais
formed.

14. Theconidiaareoval,ellipticalorgloboseinstructure
havingsmooth,rough,andofvariouscolou­rationslike
green,yellow,blueetc.
Aftermaturation,theconidiagetdetachedfromthe
motherandaredispersedbywind.
Onsuitablesubstratum,theygerminatebydeveloping
germtube.

15. BymeansofAscospores
Theascosporesarereleasedbythedis­solutionofascus
andcleistotheciumwall.Theascosporegerminatesona
suitablesubstratumbydevelopinggermtubeand
ulti­matelyintoamyceliumlikethemother.

18. 1.TheconidiophoreinAspergillusisunseptateand
unbranched.Itarisesfromaspecialized,T-shaped
thick-walledfootcell.InPenicilliumitislong,
slender,septateandbranched.Itarisesfromany
vegetativecellofthemycelium.Therearenofoot
cells.
2.InAspergillustheconidiophoresenlargeintoavesicle
atitstipwhichbearsthefinger-likesterigmata.The
wholestructurehastheformofasphericalhead.The
conidiophoreinPenicilliumendsinawhorlof
brancheswhichgiveitabroom-likeappearance.

20. Penicilliumspp.areoccasionalcausesofinfectionin
humans
resultingdiseaseisknownaspenicilliosis.
Penicilliumhasbeenisolatedfrompatientswithkeratitis,
endophtalmitis,otomycosis,necrotizingesophagitis,
pneumonia,endocarditis,peritonitis,andurinarytract
infections.
MostPenicilliuminfectionsareencounteredin
immunosuppressedhosts.
Inadditiontoitsinfectiouspotential,Penicillium
verrucosumproducesamycotoxin,ochratoxinA,whichis
nephrotoxicandcarcinogenic.Theproductionofthetoxin
usuallyoccursincerealgrainsatcoldclimates