fungi – moulds, yeasts and mushroomsc).pdfmechanisms of fungi are the great recyclers: autumn...

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© Anna Gorbushina, WS 2006/2007

Fungi –

moulds, yeasts and mushrooms


Fungi in microbiology(probably, you have heard these names already…)

Applied microbiology and biotechnologySaccharomyces cerevisiae (beer, bread)Penicillium roquefortii (cheese)Penicillium chrysogenum and Acremonium chrysogenum(antibiotics)Aspergillus niger (citric acid)

Haploid eukaryotes with fast growth ratesNeurospora crassaAspergillus nidulansSaccharomyces cerevisiae

Ecology, physiology, diversity, plant pathology etc.

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•Prokaryotes are morphologicall simple, but physiologically tremendously diverse•Planta, Fungi and Animalia have lived through this 3 domain transfromation withonly minor alterations•Protists stay the most diverse group•Fungi traditionally includ true fungi and fungi-like protists


Bacteria unicellular osmotrophicArchaea

Protista unicellular diverse: ingestion, osmotrophic

Animalia multicellular phagotrophic (ingestion)

Fungi X-cellular osmotrophic

Planta multicellular osmotrophic

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True fungi and fungi-like protistsMicroscopic organisms, but there are also huge fungiFor classification it is necessary to havepropagation structures or to use molecularbiological characters

Fungi - what is treated bymycology?


Groups traditionally treated by mycologyOomycetesChytridiomycetesZygomycetesAscomycetesBasidiomycetes

Fungi and mycology

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ProtozoaMycetozoa Mesomycetozoa

ChromistaOomycota

Zygomycota Zygomycetes

EntomophthoralesMortierellalesMucorales

Ascomycota Archiascomycetes

Pneumocystidales

HemiascomycetesSaccharomycetales

EuascomycetesChaetothyrialesClavicipitalesDothidealesEurotialesHypocrealesLeotialesMicroascalesOnygenalesOphiostomatalesPhyllachoralesPleosporalesSordariales

BasidiomycotaHymenomycetes

AgaricalesStereales

TremellalesUrediniomycetes

Sporidiales

UstilaginomycetesMicrostomatales

TilletialesUstilaginales

Eumycota

Chytridiomycota


New classification

Kingdom ProtistaPlasmodiophoromycotaDictyosteliomycotaAcrasiomycotaMyxomycotaOomycotaHyphochytriomycotaLabyrinthulomycota

Kingdom FungiChytridiomycotaZygomycotaAscomycotaBasidiomycota

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Fungi or How to define a diverse polyphyleticgroup (i)

Heterotrophic (no photosynthesis) Osmotrophic (absorptive nutrition -exoenzymes)Cell walls with chitinThallus grows in or on a substrate, isfilamentous (or unicellular) and grows in modulesEukaryotic

real nucleus, cells frequently multinuclear

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Fungi or How to define a diverse polyphyleticgroup (ii)

Life cycles diverse (from simple to complex)Sexual propagation may be present orabsentFruiting bodies (sporocarps) micro- ormacroscopic, sometimes differentiated intotissue-like structures


Fungi

eukaryotic, haploid (n)dikaryotic (n+n) and diploid (2n) periods

unmotilean exception in Fungi: spores of Chytridiomycota

Cell walls predominantly contain chitin(R=NH-CO-CH3)unicellular (yeast) and multicellualr(filamentous or mycelial fungi)Apical (tip) growthSpores as spreading and survival units

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Growth in hypha and yeastApical growthTransport system to theonly growth zone - the tipNumerousvesicles with„building units“ for cell wall synthesisSpitzenkörperYeast - different distribution of growth zones

From Bartnicki-Garcia & Lippman, 1969, © AAAS


Fungal sporesSpread (propagation) and survival

spread - quantitySurvival - thick pigmented cell walls

Asexual (mitotic division)Sexual (cell fusion and meiosis) Sometimes in fruit bodies

ProtectionSpreading mechanisms

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Fungal fruiting bodies (sporocarps)

Mushrooms - only fruitbodiesStill composed of hyphae

From Cooke&Rayner, 1984 (c) Longman


Morphology of fungi - hypha, mycelium, colony

•Mycelium has 1 to 10 µm in diameter•Tip growth•Substrate penetration•Substrate contact surface is enormous

© Polona Zalar & Nina Gunde-Cimerman

© Prof. Trinci

From Cooke&Rayner, 1984 (c) Longman

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Morphology of fungi - vegetative myceliummodifications

Mycelial strands -Serpula lacrymans

Sclerotia - mummified fruits, insect bodies, with myceliumpenetrating all through


Fungal morphology

Witch circle

© Polona Zalar & Nina Gunde-Cimerman

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General informationCell wall - chitin, cellulose, glucanesMotility: none (flagellate spores in Chytridiomycota!)Thallus - mycelial (septate, unseptate) or yeastMetabolism: aerobic, facultative anaeroby(fermentation)Life cycles

Asexual (vegetative, mitotic spores)Sexual (generative, meiotic spores)Complex, usually facultative


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ChromistaOomycota




Pneumocystidales




AgaricalesStereales


Sporidiales

UstilaginomycetesMicrostomatales TilletialesUstilaginales

Eumycota

Chytridiomycota


Oomycota•Aquatic organisms

•Water absolutelynecessary (in soil, as land plants parasites)

•Heterokont, biflagellate, spores

•Cell walls containcellulose und glucan (ß-(1-3) and ß-(1-6) glycoside bonds

•Oogamy with a complexand very specificfertilisation process

•Phytophtora infestans

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ChromistaOomycota




Pneumocystidales




AgaricalesStereales


Sporidiales



Eumycota

Chytridiomycota


Differences in propagation

Sexual propagation (all around meiosis)

Generations(sexual/asexual)

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Chytridiomycota

Zygomycota

Ascomycota

Basidiomycota

Deuteromycota (Fungiimperfecti)

Some groups of Fungi


Cell wall composition in phyla of fungi and fungal-like protists

xylomannoproteins, α-(1-3)- glucan

chitinβ-(1-3)- and β-(1-6)-glucan

Basidiomycota

galactomannoproteinsα-(1-3)- glucan

chitinβ-(1-3)- and β-(1-6)-glucan

Ascomycota

polyglucouronate, glucuronomannproteins, polyphosphates

chitinchitosan

Zygomycota

glucanchitinβ-(1-3)- and β-(1-6)-glucan

Chytridiomycota

glucancelluloseβ-(1-3)- and β-(1-6)-glucan

Oomycota

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Fungal nutrition and theirpresence in ecosystems

Osmotrophic - with a huge reactive surfaceOrganoheterotrophicRespiration/FermentationWhere they live: everywhere (soil, air, water, wood, rocks). Mainly aerated zonesStrictly anaerobic fungus: only oneChytridiomycete Neocallimastix frontalis (39°C, pH6,5) known from the rumenal ecosystem


Hypha – mycelum – colony – fruiting body

Mycelium important for all: parasites, symbionts, destruents

Penetration and substrate colonisation

Curious example: Nematode-trappingfungi

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Fungal lifestyles

Saprophytes on dead organic matter - „trashand litter“ :

soil (1g of agricaltural field soil contains10-100 m of fungal mycelium)wood (destruction and staining)various organic compounds

Symbionts with bacteria, algae, plantsParasites on animals, algae, plants


SAPROPHYTES

•Substrate mycelium, exoenzymes, osmotrophy

•Available nutrients

-carbohydrates including highly polymeric(cellulose, starch, pectine, lignine)

-proteins (including keratin)

-fats, polyols etc

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PARASITES

•Direct contact and nutritionalconnection

•Mycelium on the surface of a structure (e.g. leaf) or between thecells

•Always a direct contact betweencytoplasmatic membranes -penetration structure „haustorium“


PARASITES

•Metabiotrophic•Biotrophic•Necrotrophic

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Claviceps purpurea - sclerotia

Obligate life Obligate life cyclecycle --perfectlyperfectly adaptedadapted to to thethehost‘shost‘s life life cyclecycle

InfectionInfection isis veryvery limitedlimited --onlyonly oneone corncorn

SclerotiaSclerotia areare survivalsurvivalstructuresstructures ((winterwinter), ), afterafterthatthat a proper a proper meioticmeioticcyclecycle takestakes placeplace

VariousVarious biologicallybiologically activeactivemetabolitesmetabolites (LSD)(LSD)


SYMBIONTS

Mycorrhiza – higher plants (trees, grasses, orchids)Lichens – algae and /or cyanobacteria

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Mycotrophy of higher plants

• 80% of plant species are obligately mycotrophic, 10% -facultatively

•Fungi form a close contact with plant roots either as a coator between the root parenchyme cells•Characteristic morphology and physiology


Mycorrhiza

Mutual profitWater, P-, N- and Ca-compounds for a plant partnerCarbohydrate for a fungal partner

What happens on a contact interface?Hyphae are digestedPhosphatases of plant Glucose und succrose are transformed intotrehalose und mannitol

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Ectotrophic mycorrhiza

Fs – fungal sheath (Mantel aus Pilzhyphen, die auch außerhalb der Wurzel weiter in den Boden wachsen)Hn – Hartig‘s net (Myzel zwischen den Zellen)


Mycorrhiza stimulates growth of plants

See also: Smith, S.E., Smith, F.A. & Jakobsen, I. (2003) Plant Physiol. 133: 16-20.

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Ectotrophicmycorrhiza makes phosphorous available, also including phosphates from mineral soil horizons

Landeweert, R., Hoffland, E., Finlay, R.D., Kuyper, T.W. & Van Breemen, N. (2001) Trends Ecol. Evol. 248-253.


Lichen thallus

Form and structure aredetermined by a mycobiont

Cortex (upper and lower)Photobiont layerMedula

Flavoparmelia caperata

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FungiDiverseUbiquitous and stress-tolerantWith a huge potential (enzymes,

secondary metabolic products)Important in nature as destruents

(recyclers), symbionts and parasites; as lichens even as primary producersBiotechnologically useful


In the real world, the estimate of fungus biomass is about two tons per human being in the overall biosphere. The unseen underground feeding mechanisms of fungi are the great recyclers: autumn leaves, cornstalk debris, mountains of trash, all returned to usable form mainly by fungi. No soil fungi, no trees and forests as we know them. No waving fields of grain. No escape from unforeseen pneumonia. No athlete's foot. No bread, no booze. Give us non-mushroom mycologists a break!

Dr. Emory Simmons

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ZygomycotaChitinous cellwallsSpores in sporangiaSurvivalstructures -zygosporangia


ZygomycotaSugar fungiInsectparasitesSymbionts(VAM Mykorrhiza)

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Ascomycota

The biggest groupChitin, all protectivepigmentsSpores asexual –exogenous; sexual – in Asci


AscomycotaParasites (true mildew)Symbionts (lichens, mykorrhiza)Destruents

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BasidiomycotaChitin Dikaryoticphase(reproduction process isprolonged)Sporesexogenouson a basidium; basidia(plural) on a fruit body


BasidiomycotaSaprotrophs(wooddecomposers)Parasites(living hosts, also trees)Symbiontes(mycorrhiza)

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ChromistaOomycota




Pneumocystidales




AgaricalesStereales


Sporidiales



Eumycota

Chytridiomycota


Ameboid slime moulds - Protista

neither slimy, no mouldsno hyphaeno cell walls in the trophic phasein the trophic phase ingestion or phagocytosis fruiting bodies with cell wallsSpores as propagation unitsamoebal or plasmodial vegetative phase

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Ameboid slime moulds - Protista

Acrasiomycota: early separation from Eukarya - discoidal mitochondrial cristaeMyxomycota and Dictyosteliomycota –later development, unrelated

tubular mitochondrial crystaeNumerous differences in morphology, life cycles, flagella, cell wall composition, nutrition


Plasmodium Physarum polycephalum

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Stemonitis fusca

Physarum cinereum Diachea leucopodium

Trichia decipiens

Different types of sporangia in myxomycetes


Ameboid slime moulds

Pigments, heterotrophic (no chlorophyll)Net-work like structuresthat creep over substratesand are capable of phagocytosisrhythmic plasma-movements over cm-distancesFruiting bodies (sporangia)

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