真核微生物的形態(tài),結構和功能95-課件

Chapter2Morphology，structureandphysiologicalfunctionofeukaryotesDefinition：eukaryoticcellsarecompartmentalizedbymembran-es.Thecellcontainsseveraldifferenttypesofmembranebou-ndorganelleinwhichdifferentbiochemicalandphysiologicalprocessescanoccurinaregulatedway.

Membranesalsotransportinformation，metabolicintermediatsandend-productsfromthesiteofbiosynthesistothesiteofuse.Eukaryotesisabiggroupoflivingorganismsmadeupofeukaryoticcells.withmembraneboundnucleusandseveralorganellessuchasmitochondrionetal.anddividedbymitosis.真核生物是一大類細胞核具有核膜，能進行有絲分裂，細胞質中存在線粒體或同時存在葉綠體等多種細胞器的生物.eukaryoticmicro-organismsisagroupofMicroorganismsthatmadeupofeukaryoticcellsincludeFungi、microalgae〔〕、andprotozoa真核細胞真核生物

真核微生物peroxisomesmitochondrioncytosolchloroplastSmoothendoplasmicreticulumStructureofatypicalplantcellCytosol細胞液PlasmamembraneSecretoryvesiclesStructureofatypicalanimalcellmembraneCellwall

mitochondrionVesicals

(泡囊)

Dictyosomes(分散高爾基體)HyphalstructuresEndoplasmicreticlumribosomesmembranevacuoleCellwallmitochondrionNucleusEndoplasmicreticulumYeaststructuresYeaststructures

“菌物界’’這個名詞是我國學者裘維蕃等于1990年提出的，并已·得到學術界的一定支持，這是指與動物界、植物界相并列的一大群無葉綠素、依靠細胞外表吸收有機養(yǎng)料、細胞壁一般含有幾丁質的真核微生物。一般包括真菌、粘菌和假菌(卵菌等)3類。真菌是最重要的真核微生物，故是本章的重點，它們的特點是：①無葉綠素，不能進行光合作用；②一般具有興旺的菌絲體；③細胞壁多數(shù)含幾丁質；④營養(yǎng)方式為異養(yǎng)吸收型；⑤以產(chǎn)生大量無性和(或)有性孢子的方式進行繁殖；⑥陸生性較強

Fungiarefilamentous,non-photosynthetic,eukaryoticmicroorganismsthathaveaheterotrophicnutrition.Theirbasiccellularunitisdescribedasahypha.Thisisatubularcellwhichissurroundedbyarigid,chitin-containingcellwall.Thehyphaextendsbytipgrowth,andmultipliesbybranching,creatingafinenetworkcalledamycelium.Hyphaecontainnuclei,mitochondria,ribosomes,Golgiandmembrane-boundvesicleswithinaplasma-membraneboundcytoplasm.Thesubcellularstructuresaresupportedandorganizedbymicrotubulesandendoplasmicreticulum.Thecytoplasmiccontentsofthehyphatendtobeconcentratedtowardsthegrowingtip.Olderpartsofthehyphaareheavilyvacuolatedandmaybeseparatedfromtheyoungerareasbycrosswallscalledseptae.Notallfungiaremulticellular,someareunicellularandaretermedyeasts.Thesegrowbybinaryfissionorbudding,creatingnewindividualsfromtheparentcell.Mould〔Mold〕DefinitionMoldarefilamentous,nonphotosynthetic,eukaryoticmicroorganismsthathaveaheterotrophicnutrition〔filamentousfungi〕。

MorphologyandstructureHyphaandmycelium菌絲與菌絲體lowerfungi——non-septatemyceliumshigherfungi——septatemyceliumwithelaborate、perforateseptaThehyphaextendsbytipgrowth,andmultipliesbybranching,creatingafinenetworkcalledamycelium.〔pluralmycelia〕Myceliacanbedividedintovegatativemyceliumandaerialmycelium〔營養(yǎng)菌絲體和氣生菌絲體〕Basicunit——hypha〔pl。hyphae〕Thisisatubularcellwhichissurroundedbyarigid,chitin-containingcellwall.Hyphaecontainnuclei,mitochondria,ribosomes,Golgiandmembrane-boundvesicleswithinaplasma-membraneboundcytoplasmmembraneCellwall

mitochondrionVesicalsDictyosomes(分散高爾基體)HyphalstructuresSpecializedmorphologyofvegetativemycelium

營養(yǎng)菌絲體的特化形態(tài)Rhizoid假根——Rhizopus

Stolon匍匐菌絲——Mucorales、Rhizopus

Haustorium吸器Adhesivecell附著胞Adhesivebranch附著枝Sclerotium菌核Rhizomorph，funiculus菌索

ringandnet菌環(huán)和菌網(wǎng)1)假根(rhizoid)是Rhizopus(根霉屬)等低等真菌匍匐菌絲與固體基質接觸處分化出來的根狀結構，具有固著和吸取養(yǎng)料等功能(2)匍匐菌絲(stolon)又稱匍匐枝。毛霉目(Mueorales)真菌在固體基質上常形成與外表平行、具有延伸功能的菌絲，稱匍匐菌絲。最典型的可在Rhizopus中見：在固體基質外表的營養(yǎng)菌絲分化為匍匐菌絲，在其上每隔一段距離可長出伸人基質的假根根霉的形態(tài)和構造和伸向空間的孢囊梗，隨著匍匐菌絲的延伸，不斷形成新的假根和孢囊梗，這類真菌會隨基質的存在而向四處快速蔓延，根本就不會形成像在其他真菌中常見的那樣有固定大小和形態(tài)的菌落。sporangium(3)吸器(haustorium)由幾類專性寄生的真菌如銹菌目(Uredinales)、霜霉目(Peronosporales)和白粉菌目(Erysiphales)等的一些種所產(chǎn)生。吸器是一種只在宿主細胞間隙間蔓延的營養(yǎng)菌絲上分化出來的短枝，它可侵入細胞內形成指狀、球狀或絲狀的構造，用以吸取宿主細胞內的養(yǎng)料而不使其致死。(4)附著胞(adhesivecell)許多寄生于植物的真菌在其芽管或老菌絲頂端會發(fā)產(chǎn)膨大，分泌粘狀物，借以牢固地粘附在宿主的外表，此即附著胞。在其上再形成針狀感染菌絲，以侵入宿主的角質表皮而吸取養(yǎng)料。

(5)附著枝(adhesivebranch)假設干寄生真菌由菌絲細胞生出1—2個細胞的短枝，將菌絲附著于宿主體上，〔6〕菌核〔sclerotium)是一種形狀、大小不一的休眠菌絲組織，在不良外界條件下：可保存數(shù)年生命力。菌核形狀有大有小，大的如茯苓(大如小孩頭)，小的如油菜菌核(形如鼠糞〕。菌核的外層色深、堅硬、內層疏松，大多呈白色?！?〕菌索〔〕一般由傘菌等產(chǎn)生，為白色根狀菌絲組織，功能為促進菌體蔓延和抵御不良環(huán)境。通?？稍诟嗟臉淦は潞偷叵掳l(fā)現(xiàn)。(8)菌環(huán)(loop)和菌網(wǎng)(net)捕蟲菌目(zoopasdes)和一些半知菌的菌絲常會分化成圈環(huán)或網(wǎng)狀的特化菌絲組織，用以捕捉線蟲或其他微小動物，然后進一步從這類環(huán)或網(wǎng)上生出菌絲侵入線蟲等體內，吸收養(yǎng)料〔9〕子實體〔fruitingbody，sporocarp，fructification〕ColonialgrowthHyphaltipgrowthallowsfungitoextendintonewregionsfromapointsourceorinoculum(接種物).Olderpartsofthehyphaeareoftenemptiedofcontentsasthecytoplasmistakenforwardswiththegrowingtip.(老的菌絲通常缺乏內含物，因為細胞質流向生長點)Thiscreatestheradiatingcolonialpatternseenonagarplates,inringworminfectionsofskinandfairyringsingrasslawns.Onlyhyphaltipscontributetoextensiongrowth.Howeverolderhyphaecangrowaeriallyordifferentiatetoproducesporingstructures〔只有菌絲頂端對延伸生長起作用，而老菌絲可以進行氣生生長或分化出產(chǎn)孢子的結構〕MyceliuminagarAgar

SurfacemyceliumKineticsofgrowthFungalgrowthinagivenmediumfollowsthegrowthphasesoflag,acceleration,exponential,linear,retardation,stationaryanddecline〔延遲期、加速期、指數(shù)期、直線期、減速期、穩(wěn)定期、衰亡期〕.Exponentialgrowthoccursonlyforabriefperiodashyphaebranchesinitiated,andthenthenewhyphaextendsatalinearrateintouncolonizedregionsofsubstrate.Lifecycles

Allfungiarecharacterizedbyhavingaperiodofvegetativegrowthwheretheirbiomassincreases.Thelengthoftimeandtheamountofbiomassneededbeforesporulationcanoccurvaries.Almostallfungireproducebytheproductionofspores,butafewhavelostallsporingstructuresandarereferredtoasmyceliasterilia(不育菌絲體).Differenttypesofsporeareproducedindifferentpartsofthelifecycle.ReproductioninfungiAllfungiundergoaperiodofvegetativegrowthwheretheirmyceliumexploitsasubstrate.Thisstageisfollowedbyasexualandsexualreproduction..Therearetwoconflictingrequirementsfungihavefortheirspores.Sporesmustallowfungitospread,buttheymustalsoallowthemtosurviveadversecondi-tions.Theserequirementsaremetbydifferenttypesofspores.Small,lightsporesarecarriedfurthestfromparentmyceliuminairandthesearethedispersalspores〔釋放型孢子〕.Theyareusuallytheproductsofasexualsporulation,thesporangiosporesandtheconidiospores,andsospreadgeneticallyidenticalindividualsaswidelyaspossible.Geneticdiversityismaintainedbysexualreproduction,andthesporeproductsareoftenlargerestingspores〔休眠孢子〕thatwithstandadverseconditionsbutremainclosetotheirsiteofformation.Sporesthereforevarygreatlyissize,shapeandornamentation,andthisvariationreflectsspecializationofpurpose.Fungalspores：sporesallowfungitospread,tomaintaingeneticdiversityandtosurviveadverseconditionsReproductioninfungi

sporedischarge

：Sporesthathaveadispersalfunctioncanbereleasedfromtheirparentmyceliumbyactiveorpassivemechanisms.Asmanysporesarewinddispersed,theyareproducedindryfriablemasseswhicharepassivelydischargedbywind.Othersporesarepassivelydischargedbywaterdropletssplashingsporesawayfromparentmycelium.Sporesmaybedischargedfromparentmyceliumbypassiveoractivemeans.Passivemechanismsincludeusingwindandwaterasdispersants;activemechanismsuseexplosiveprinciples.FungalsporedischargeSporesintheatmosphere〔air-bornefungalspores〕canbecarriedgreatdistances。Theirpresenceintheaircanhaveimpactonhumanhealthastheycancauseallergicrhinitus〔hayfever〕andasthma。Manyplantdiseasesthatcausegreateconomiclossesareairborne。canaffecthuman,animalandplanthealth.Theycancauseallergiesandspreadplantdisease.AirsporaFungireproducebytheformationofsexualorasexualspores

AsexualreproductionfissionArthrosporeBuddingblastosporeOtherasexualsporeZoosporeChlamydosporeSporangiosporeconidiospora

Sexualreproduction

OosporeZygosporeAscosporeBasidiospore節(jié)孢子(arthrospore)某些真菌生長到一定階段，菌絲中間形成許多隔膜，接著從隔膜處斷裂成許多竹節(jié)似的無性孢子，稱為節(jié)孢子，也稱為粉孢子。最典型的例于是白地霉(Geotrichumcandidum).arthrosporeBlastospore(芽孢子)

這和酵母菌的出芽一樣，它是由母細胞生芽而形成的。當芽長到正常大小時，脫離母細胞，或仍連在母細胞上。如玉蜀黍黑粉菌(Ustilagomaydis)能產(chǎn)生芽孢子。某些毛霉或根霉在液體培養(yǎng)基中形成的被稱為酵母型細胞，也屬芽孢子。又稱厚壁孢子或厚膜孢子。某些真菌生長到—定階段，在菌絲的頂端或中間有局部細胞的細胞質密集在一起，變圓，然后在其四周生出厚壁，或原細胞壁加厚，形成圓形、紡錘形的無性休眠體，來抵抗外界不良的環(huán)境條件。例如總狀毛霉(Mucorracemosus)往往在菌絲中間形成許多厚垣孢子schlamydospore〔厚垣孢子〕

無性繁殖產(chǎn)生的孢子在孢子囊(Sporange)內,孢子囊一般生在氣生菌絲的頂端或生在孢囊梗(sporangiophore)的頂端。在形成孢子囊前，首先有多核的原生質密集于此處，使其膨大，并在下方生出橫隔，形成圓形的囊狀物，然后其中原生質體割裂成許多小塊，每—塊發(fā)育成為—個孢子囊孢子。因而每一·個孢子囊所含有的孢子的數(shù)—般都相當多。就孢子囊孢子而言,—般有二類,一種具有—根或2~3根鞭毛，能夠游動，所以稱游動孢子(zoospore)。例如腐霉(即thium)。另一種無鞭毛，不能游動，又稱靜止擔于。sporangiospore

(孢子囊孢子)游動孢子

conidium

(分生孢子)

分生孢子的形成方法其形成方式有兩種，一種是在分生孢子梗的頂端突出，發(fā)育成第一個孢子。梗再伸長形成第二個孢子，如此重復形成一串孢子。這樣形成的分生孢子，頂端的最老。曲霉屬和青霉屆的分生孢子形成，即屬于此類型。另一種是在第—個分生孢子形成時，柄的長度已到達最高，由第一個分生孢子頂端生長出第二個分生孢子，如此重復形成一串孢子。這樣形成的分生孢子，下部的最老。如枝孢霉屬(Cladosporium)的分生孢子形成即屬于此類型。Plastickitchencuttingboardsurface-rodbacteriainasmoothmatrix;filamentousbacteria(絲狀菌)-smoothovalcells;fungalhyphae(真菌菌絲)withtexturedspores(結構孢子)(x2,270)conidiumZoospore〔游動孢子〕Asexualspore，usually

producedbyfungilivinginwater.Motilezoosporesinmotilesporangiadifferentiatedfromswelledhyphaltipshaveasingleposteriorflagellum。Thestructureoftheflagellumis9+2，somehastwoflagella.霉菌的有性繁殖是經(jīng)過不同性別的細胞結合(質配和核配)后，產(chǎn)生一定形態(tài)的孢子來實現(xiàn)的，這種孢子稱為有性孢子。繁殖過程可分為三個階段：第—個階段為質配；第二個階段為核配，產(chǎn)生二倍體的核；第三個階段是減數(shù)分裂，恢復核的單倍體狀態(tài)。大多數(shù)真菌菌體是單倍體的。有性孢子通常有以下幾種：Sexualreproduction

菌絲分為雄器(antheridium)和藏卵器(oogonium)。藏卵器中有一個或數(shù)個卵球(oosphere)。當雄器和藏卵器相配時，雄器中細胞質與細胞核，通過受精管而進入藏卵器，與卵球結合形成卵孢子。圖所示是德巴利腐霉的卵孢子的形成。oospore

(卵孢子)

〔b〕同宗結合〔a〕異宗結合根霉的接合孢子Zygospore〔接合孢子〕ascospore〔子囊孢子〕形成子囊孢子是子囊菌的主要特征。子囊中孢子數(shù)目通常為1~8個，或為2n。典型的子囊中有8個孢子。大多數(shù)霉菌的子囊是包裹在子囊果〔ascocarp〕中。子囊果有三種類型子囊殼perithecium子囊盤apothecium閉囊殼cleistotheciumSexualreproductioninthisgroupoccursaftersomaticfusionofdifferentmating-typemycelia.Atransientdiploidphaseisrapidlyfollowedbytheformationofascosporeswithinsac-shapedascidifferentiatedfrommodifiedhyphaltips.Intheinitialstagesofascaldevelopmenthookedhyphaltipsform,calledcroziers〔產(chǎn)囊絲鉤〕orshepherds‘crooks〔牧羊杖〕becauseoftheirshape.Theyhavedistinctiveseptaeattheirbasewhichinsurethattwodifferentmating-typenucleiaremain-tainedintheterminalcell.Formationoftheseptaeiscoordinatedwithnucleardivision.Inyeastsalltheseeventsoccurwithinonecell,afterfusionoftwomating-typecells,thewholecellbeingconvertedintoanascus.TheformationofascosporesSexualreproductionintheascomycetesInmorecomplexAscomycetesmanyasciformtogether,creatingafertiletissuecalledahymenium〔叫子實層的能育組織〕.Insomegroupsthehymeniumcanbesupportedorevenenclosedbylargeamountsofvegetativemycelium.Thewholestructureiscalledafruitbodyorsporocarp〔子囊果〕andisusedasamajortaxonomicfeature.Theycanbecomelargeenoughtobeseenwiththenakedeye.Flask-shapedsexualreproductivebodiesarecalledperithecia,cup-shapedbodiesarecalledapotheciaandclosedbodiesarecalledcleistothecia.Thesestructureshaveevolvedtoprotecttheasciinsporedispersal，butthehymeniumitselfisunafectedbythepresenceofwater。TheformationofsporocarpanditsformsCup-shapedapotheciumFlask-shapedperitheciumClosedcleistotheciumAsciAsciAscuscontainingascosporesBasidiomycetefungirarelyreproduceasexually.Sexualreproductionisbytheformationofbasidiosporesonthegillsorporesoflargefruitbodies.Thisgroupoffungiarecharacterizedbythemostcomplexandlargestructuresfoundinthefungi.Theyarealsodistinctiveinthattheyveryrarelyproduceasexualspores.Muchofthelifecycleisspentasvegetativemycelium,exploitingcomplexsubstrates.Apreliminaryrequisitefortheonsetofsexualreproductionistheacquisitionoftwomatingtypesofnucleibythefusionofcompatiblehyphae.Singlerepresentativesofthetwomating-typenucleiareheldwithineveryhyphalcompartmentforextendedperiodsoftime.Thisistermedadikaryoticstate〔雙核期〕,anditsmaintenancerequireselaborateseptumformationduringgrowthandnucleardivision.BasidiosporeOnsetofsexual-sporeformationistriggeredbyenvironmentalconditionsandbeginswiththeformationofafruitbodyprimordium〔子實體原基〕.Dikaryoticmycelium〔雙核菌絲體〕expandsanddifferentiatestoformthelargefruitbodieswerecognizeasmushroomsandtoadstools〔毒蕈〕.Diploidformationandmeiosisoccurwithinamodifiedhyphaltipcalledabasidium。Basidiumformation核融合Nuclearfusion減數(shù)分裂meiosis擔孢子梗sterigmataBasidiospores擔孢子Basidium〔擔子〕BasidiumandbasidiosporeformationFoursporesarebuddedfromthebasidium.Basidiaformtogethertocreateahymeniumwhichishighlysensitivetothepresenceoffreewater.Thehym-eniumisdistributedoversterile,dikaryoticsupportingtissueswhichprotectitfromrain.Thehymeniumcanbeexposedongillsorporesbeneaththefruitbody,seeninthetoadstoolsandbracketfungi,orenclosedwithinchambersasinthepuffballsandtrufflesFormationofbasidiosporepuffball〔馬勃〕Bracket〔檐狀傘〕Toadstool〔毒蘑菇〕Hymenenium〔子實層〕Structureofsexualsporocarpsinthebasidiomycetesbasidiospore〔擔孢子〕擔孢子是擔子菌特有的特征。它是一種外生孢子，經(jīng)過兩性細胞核配合后產(chǎn)生。因為它生在擔子上，所以稱為擔孢子。典型的擔子菌的擔子上有四個擔孢子。各種擔孢子的形狀及外表特征Foodrelatedmolds1.Aspergillus曲霉屬2.penicillium〔青霉屬〕3.Rhizopus〔根霉屬〕4.sporotrichum(側孢霉屬)5.Thamnidium(枝霉屬)6.Alternaria〔交鏈孢屬〕7.Botrytis〔葡萄孢霉〕〔木霉屬〕〔紅曲屬〕〔赤霉屬〕11.Cordyceps〔蟲草屬〕〔地霉屬〕〔長蠕孢霉〕foodrelatedMouldsAspergillus曲霉屬分生孢子初生小梗孢子穗小梗次生小梗頂囊足細胞ConidiaprimarysterigmaconidialheadsterigmesecondarysterigmaVesiclefootcellMorphologyofConidialheadisthebasisforspeciesidentification孢子穗的形態(tài)是菌種鑒定的依據(jù)AspergillusRelationshipwithfood——beneficialFermentationindustrysoysauce釀醬vinegar制醋曲

fermentedbeancurd腐乳alcoholbeverage釀酒Foodprocessingorganicacid有機酸enzyme酶制劑

淀粉酶蛋白酶果膠酶等Relationshipwithfood——harmfulUsuallydistributedonthesurfaceoffollowingfoodstuff：Cakes、fruits、vegetables、meat、grainandotherorganicobjects。Causingfollowingconsequences：Gomouldy；becomemildewedProduceorsecretecarcinogenicsubstance〔blastomogen〕致癌物質eg。aflatoxin〔黃曲霉毒素〕Foodrelatedmolds——penicillium〔青霉屬〕十分接近于曲霉，在自然界分布很廣，長生長在腐爛的柑橘皮上，呈青綠色，不少種類引起食品變質，但也用來生產(chǎn)青霉素和有機酸等。青霉菌菌絲與曲霉相似，但無足細胞，孢子穗結構也不同。其分生孢子梗頂端不膨大，而是經(jīng)過屢次分枝產(chǎn)生幾輪對稱或不對稱的小梗，然后在小梗的頂端產(chǎn)生成串的分生孢子。青霉菌的孢子穗形狀似掃帚狀。分生孢子球形、橢圓形或短柱形，一般呈藍綠色。Plastickitchencuttingboardsurface-rodbacteriainasmoothmatrix;filamentousbacteria(絲狀菌)-smoothovalcells;fungalhyphae(真菌菌絲)withtexturedspores(結構孢子)(x2,270)根霉在自然界分布廣泛，經(jīng)常出現(xiàn)在淀粉質食品上，引起糧食、食品腐爛、腐敗。I工業(yè)上常利用根霉生產(chǎn)糖化酶，甜酒曲中主要菌種也是根霉。此外，根霉也可以用來生產(chǎn)有機酸等其它物質。Foodrelatedmolds——Rhizopus〔根霉屬〕Rhizoid假根Stolen匍匐絲

sporangeUauallyblacksporangiophore菌絲分隔·分生孢子梗分枝，頂端產(chǎn)生分生孢子。分生孢子單細胞，梨形。菌落呈奶油色澤，時間長后，為枯燥粉末狀。已經(jīng)報告該菌能在O~C以下生長，常在冷藏肉中形成白色斑點。

foodrelatedmolds—sporotrichum

(側孢霉屬)S．Carnis肉色側孢霉Conidium分生孢子Conidiophore分生孢子梗Causethedeteriorationofvegetablesandfruitconidiumconidiophore形狀大小不定，數(shù)個連接成鏈，暗褐色，有縱橫隔膜，呈壁磚狀。大多數(shù)不分支，較短，單生或成簇，暗褐色。Foodrelatedmolds——Alternaria〔交鏈孢屬〕septatemyceliumFoodrelatedmolds——Botrytis〔葡萄孢霉〕conidiophoreconidium分生孢子梗頂端形成樹枝狀分支，分支頂端細胞常常膨大，在短的小梗上著生分生孢子，如一串葡萄。卵圓形，無色或暗褐色。常產(chǎn)生外形不規(guī)那么的黑色菌核〔sclerotium〕。分布在許多植物和植物食品上，形成一層“灰色霉〞，引起水果、蔬菜的腐敗。Foodrelatedmolds——Trichoderma〔木霉屬〕Sphericalorelliptical〔oval〕，smmothorrough，yellow-greenconidiaColorlesshypha，withseptaandbranches，producechlamydosporesBottle-likesterigme瓶狀小梗Sporeheadgathered〔conglutenated〕bymucus〔slime〕Foodrelatedmolds——Trichoderma〔木霉屬〕Colonygrowsrapidly，likecottonfibre〔棉絮狀〕，whiteatfirst，laterbecomegreen。Spore-producingareatakeson〔has〕concentriccirclesSonespecieshascellulolyticactivity，thereforecanbeusedtoproducecellulasetomanufacturesugarswithcellularwaste〔下腳〕，starchprocessingandfoodprocessingMoldygrain，fruitandvegetablesMildewandrotofcellularmaterial。Foodrelatedmolds——Monascus〔紅曲屬〕CansecreteredpigmentThesourceofnaturalredpigmentinthefoodprocessing，forinstanceredrice〔ang-kak〕usedintheprocessingofredfermentedbeancurd，bevarageandmeatispreparedfromMonascus。Typeculturethatcommonlyused：M.purpureus〔紫紅曲〕Foodrelatedmolds——Monascus〔紅曲屬〕Colonyfeatures：membranouscolonycoversthewholemaltextractplate，myceliumiswhiteatfirst，laterbecomesred，red-purple，thewater-solublepigmentsaresecretedintothemedium。conidiumFoodrelatedmolds——Monascus〔紅曲屬〕1~3initiatecleistothecium4~5prematurecleistothecium

6maturecleistothecium

cleistotheciumof

紫紅曲的閉囊殼Foodrelatedmolds——Gibberella〔赤霉屬〕reproductionscarcelyproduceSexualgeneratin〔gamobium，sexualprogeny〕，sexualsporeisascosporeinspherical，smoothandblueperithecium〔子囊殼〕。AsexualreproductionproducetwotypesofconidiumSmalltype：singlecellular，spherical，ellipticaltolongcolumn，colorlessorothercolorsLargetype：multicellularwithsepta，Sickle-likeorlongcolumn，ColorlessorothercolorsFoodrelatedmolds——Gibberella〔赤霉屬〕Gibberellinorabbeymycin〔赤霉素〕MetabolicproductofGibberella，isakindofhormonewiththefollowingfunction：1.Stimulateplantgrowth2.Breakthedormancyofseedandtuber3.IncreasetheyieldofvegetablesespeciallyleafyvegetablesFoodrelatedmolds——Cordyceps〔蟲草屬〕Formation：Theinsectbodyparasitizedbythefungiwasfullofmycelium〔sclerotium菌核〕andmummified，stem-headlikeorrodlikestroma〔pluralstromata子座〕growsoutfromitsfrontend。Inchworm尺蠖

Stroma〔grass〕usuallysingle，scarcely2or3，4~11cminlength。peritheciumAscus〔asci〕ascosporeCordycepssinesis冬蟲夏草Foodrelatedmolds——geotrichum〔地霉屬〕Reproductionbyfission，septatehypha，hyphamaybreakintoarthrospore，withoutblastospore。Alwaysexistedinsauerkraut〔kimchi，pickles泡菜〕，fecund，organicfertilizer，rottenfruitandvegetablesandotherplantresidues。ArthrosporegerminationHyphabreaksintofragment----arthrosporeG.Candidum(白地霉)Foodrelatedmolds——helminthosporium〔長蠕孢霉〕conidiophoreconidiumColorlessorgrayseptatemycelium，septateconidiophore，conidiumisblack-gray，usuallyhas4~6cells，manyfungiofthegeneraarebothparasiteandsaprobe〔saprophyticbacterium，saprogen，saprotroph，腐生菌〕Foodrelatedmolds——geotrichum〔地霉屬〕Somespecieshashighnutritionalvalue,hasthefollowingusages:1.Edibleorasforagesupplement2.Nucleicacidextraction3.FatsynthesisEukaryote——yeastDefinition：yeastisagroupofunicelledeukaryoticmicroorganismsreproducedbybudding.

Generallyitreferstoallsingle-celledeukaryotesthatcanfermentcarbohydrates.Eukaryote——yeast

It‘sakindofmicrobesutilizedearlybyhumanbeing.

Mainlyexistsintheacidicenvironmentwithhighsugarcontentsuchasonthefruits，vegetables，flowerhoneyandconfect，orintheorchardsoil.Mostyeastsaresaprophyteandbeneficialtohumanbeing，onlyafewareparasitismandcancausethehumanbeing，plantandanimaldiseases.

Someyeastscanleadtothedeteriorationoffruitjuice，jam，honey，alcoholbeverage，andmeat.YeastcellmorphologyandstructureMostyeastareunicellusuallyarespherical，ovalorcolumnshape，somespeciesmayformlotusrootshapedpseudomycelium.

DiagramofyeastcellstructureSaccharomycescerevisiaeis

the

mosttypicalandthemostimportantyeast.Thefigurerightshowsitscellstructure.membranevacuoleCellwallmitochondrionNucleusEndoplasmicreticulumThemajorcomponentsofyeastcellwallareglucan〔葡聚糖〕andmannan〔甘露聚糖〕，anddifferentamountofproteins，lipidsandchitin〔幾丁質〕.Infantcellshashomologouscytoplasm，latervacuoleemerged.Yeaststructures

Colonialmorphology

Likebacterialcolonies，yeastcolonyhasfollowingfeatures：wettish〔humid〕、alittletransparent，withlubricous〔光滑的slippery〕surfaceandeventextureandcanbeeasilypickedup，theobversesideandthereversoside，theedgeandthecenterhasthesamecolor.Otherhand，itisbigger，thicker，denser，andalittleopaquethanthatofbacterium.Comparedwithbacteria，itscolonyonlyhasseveralcolors，normallyismilkwhiteorcandlewhite〔礦燭色〕，fewarered，oneortwoisblack.Thosewithoutpseudomyceliumhasbulgedcolonywithroundedge，whileCandidahastheflatcolonywithcoarsebrinkandsurface.Reproductionofyeast

Budding:byallyeastsAsexualfission:byschizosaccharomycetesarthrosporeAsexualsporulationballistosporechlamydosporeSexual:byformationofascusandascosporeBuddingWhenyeastgrowsonaplateofrichnutritionandunderoptimalculturecondition，itmultiplyrapidly，nearlyallcellsarebudding，therefore，conglomeratedintocellclusters〔balls〕.Afteraseriesofbudding，ifdaughteryeastsdon‘tdepartfromparentcells，andonlylinkedbynarrowandsmallarea，thusformedlotusrootshapedcellstringscalledpseudohyphae.PseudohyphaeandeuhyphaeOtherwise，cellslinkedandtheseptaareaisthesameascelldiameterformedlaemodipodiform〔竹節(jié)形〕cellstrings，thatiscalledeuhyphaeeuhyphae。Whendaughteryeastdepartfromtheparentcell，Scarwasleavedonbothofthem，calledbudscar〔onparentcell〕andbirthscar〔ondaughtercell〕respectively.Budscarandbirthscar光學顯微鏡下看到的酵母細胞這里顯示的菌種是用來發(fā)面團以及將葡萄汁轉變成酒的那些細胞。他們繁殖時先出芽，進而不對稱分裂為一大一小兩個子細胞釀酒酵母〔saccharomycescerevisiae〕Foodrelatedyeasts(1)——saccharomyces〔酵母屬〕Saccharomyceswidelycolonizedonfr