【食品課件】第二章真核微生物的形態(tài)結(jié)構(gòu)和功能95

1、Chapter 2Morphology，structure and physiological function of eukaryotesDefinition： eukaryotic cells are compartmentalized by membran-es .The cell contains several different types of membrane bou- nd organelle in which different biochemical and physiological processes can occur in a regulated way. Mem

2、branes also transport information， metabolic intermediats and end-products from the site of biosynthesis to the site of use.Eukaryotes is a big group of living organisms made up of eukaryotic membrane bound nucleus and several organelles such as mitochondrion divided by mitosis.真核生物是一大類細胞核具有核膜，能真核生物

3、是一大類細胞核具有核膜，能進行有絲分裂，細胞質(zhì)中存在線粒體或同時存在葉綠體等多種細胞器的生物進行有絲分裂，細胞質(zhì)中存在線粒體或同時存在葉綠體等多種細胞器的生物. eukaryotic micro-organisms is a group of Microorganisms that made up of eukaryotic cells include Fungi、microalgae（）、（）、and protozoa真核細胞真核細胞真核生物真核生物 真核微生物真核微生物peroxisomesmitochondrioncytosolchloroplastSmooth endoplasmic

4、reticulumStructure of a typical plant cellCytosol細胞液Plasma membraneSecretory vesiclesStructure of a typical animal cellmembraneCell wall mitochondrionVesicals (泡囊泡囊) Dictyosomes (分散高爾基體)Hyphal structuresEndoplasmic reticlumribosomesmembranevacuoleCell wallmitochondrionNucleus Endoplasmic reticulumYe

5、ast structuresYeast structures 真核微生物主要包括真核微生物主要包括菌物界菌物界(Mycetalia或廣義的或廣義的“Fungi”)中的真菌中的真菌(Eumycota或狹義的或狹義的“Fungi”，即，即True Fungi)、粘菌粘菌(Myxomycota或或Fungilike Protozoa)、假菌假菌(Chromista或或Pseudofungi)，植物界植物界(Plantae)中的顯微藻類中的顯微藻類(Algae)和和動物界動物界(Animalia)中的原生動物中的原生動物(Protozoa)Major groups of eukaryotic micr

6、oorganisms 真核微生物的主要類群真核微生物的主要類群 植物界植物界 （plantae）：顯微藻類）：顯微藻類 algae 動物界（動物界（animalia）：原生動物）：原生動物 protozoa 真核微生物真核微生物 黏菌黏菌myxomycota 假菌假菌pseudofungi 菌物界（菌物界（mycetalia） 單細胞真菌單細胞真菌unicellular fungi 真菌真菌 eumycota 絲狀真菌絲狀真菌filamentous 大型子實體大型子實體 蕈菌蕈菌 mushroomMajor groups of eukaryotic microorganisms Eukaryo

7、tic microorganisms“菌物界菌物界這個名詞是我國學(xué)者裘維蕃等于這個名詞是我國學(xué)者裘維蕃等于19901990年提出的，并已年提出的，并已得到學(xué)術(shù)界的一定支持，得到學(xué)術(shù)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、依靠細胞表面吸收有機養(yǎng)料、細胞壁一綠素、依靠細胞表面吸收有機養(yǎng)料、細胞壁一般含有幾丁質(zhì)的真核微生物。一般包括真菌、般含有幾丁質(zhì)的真核微生物。一般包括真菌、粘菌和假菌粘菌和假菌( (卵菌等卵菌等)3)3類。類。真菌是最重要的真核微生物，故是本章的重點，它們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：的特點是：

8、無葉綠素，不能進行光合作用；無葉綠素，不能進行光合作用；一般具有發(fā)達的菌絲體；一般具有發(fā)達的菌絲體；細胞壁多數(shù)含幾丁質(zhì)；細胞壁多數(shù)含幾丁質(zhì)；營養(yǎng)方式為異養(yǎng)吸收型；營養(yǎng)方式為異養(yǎng)吸收型；以產(chǎn)生大量無性和以產(chǎn)生大量無性和( (或或) )有性孢子的方式進行繁殖；有性孢子的方式進行繁殖；陸生性較強陸生性較強Fungi are filamentous, non-photosynthetic, eukaryotic microorganisms that have a heterotrophic nutrition . Their basic cellular unit is described as a

9、 hypha . This is a tubular cell which is surrounded by a rigid, chitin-containing cell wall. The hypha extends by tip growth, and multiplies by branching, creating a fine network called a mycelium. Hyphae contain nuclei, mitochondria, ribosomes, Golgi and membrane-bound vesicles within a plasma-memb

10、rane bound cytoplasm . The subcellular structures are supported and organized by microtubules and endoplasmic reticulum. The cytoplasmic contents of the hypha tend to be concentrated towards the growing tip. Older parts of the hypha are heavily vacuolated and may be separated from the younger areas

11、by cross walls called septae. Not all fungi are multicellular, some are unicellular and are termed yeasts. These grow by binary fission or budding, creating new individuals from the parent cell.Mould （Mold） nDefinition Mold are filamentous, nonphotosynthetic, eukaryotic microorganisms that have a he

12、terotrophic nutrition（filamentous fungi）。 Morphology and structureHypha and mycelium菌絲與菌絲體 lower funginon-septate myceliums higher fungiseptate mycelium with elaborate、 perforate septa The hypha extends by tip growth, and multiplies by branching, creating a fine network called a mycelium. （plural my

13、celia）Mycelia can be divided into vegatative mycelium and aerial mycelium（營養(yǎng)菌絲體和氣生菌絲體）Basic unithypha（pl。 hyphae） This is a tubular cell which is surrounded by a rigid, chitin-containing cell wall. Hyphae contain nuclei, mitochondria, ribosomes, Golgi and membrane-bound vesicles within a plasma-memb

14、rane bound cytoplasm membraneCell wall mitochondrionVesicals Dictyosomes (分散高爾基體)Hyphal structuresSpecialized morphology of vegetative mycelium營養(yǎng)菌絲體的特化形態(tài)營養(yǎng)菌絲體的特化形態(tài)nRhizoid 假根Rhizopus nStolon 匍匐菌絲Mucorales 、Rhizopus nHaustorium 吸器nAdhesive cell 附著胞nAdhesive branch 附著枝nSclerotium 菌核nRhizomorph ，funicu

15、lus菌索n ring and net 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(zhì)接觸處分化出來的根狀結(jié)構(gòu)，具有固著和吸取養(yǎng)料等功能 (2)匍匐菌絲匍匐菌絲(stolon)又稱匍匐枝。毛霉目又稱匍匐枝。毛霉目(Mueorales)真菌在固體基真菌在固體基質(zhì)上常形成與表面平行、具有延伸功能的菌絲，稱匍匐菌絲。最典質(zhì)上常形成與表面平行、具有延伸功能的菌絲，稱匍匐菌絲。最典型的可在型的可在Rhizopus中見：在固體基質(zhì)表面的營養(yǎng)菌絲分化為匍匐菌中見：在固體基質(zhì)表面的營養(yǎng)菌絲分化為匍匐菌絲，在其上每隔一段距離絲，在其上每隔一段距離可長出伸人基質(zhì)的假

16、根可長出伸人基質(zhì)的假根 根霉的形態(tài)和構(gòu)造和伸向空間的孢囊梗，根霉的形態(tài)和構(gòu)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(zhì)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?；|(zhì)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。見的那樣有固定大小和形態(tài)的菌落。sporangium(3)吸器吸器(haustorium) 由幾類專性寄生的真菌如銹菌目由幾類專性寄生的真菌如銹菌目(Uredinales)、霜霉目、霜霉目(Peronosporales)和白粉菌目和白粉菌目

17、(Erysiphales)等的一些種所產(chǎn)生。吸器是一種只在宿主細等的一些種所產(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(nèi)形成指狀、球狀或絲狀的構(gòu)造，用以吸取宿主細胞內(nèi)胞內(nèi)形成指狀、球狀或絲狀的構(gòu)造，用以吸取宿主細胞內(nèi)的養(yǎng)料而不使其致死。的養(yǎng)料而不使其致死。(4)附著胞附著胞(adhesive cell) 許多寄生于植物的真菌在其芽管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)或老菌絲頂端會發(fā)產(chǎn) 膨大，分泌粘狀物，借以牢固地粘附在膨大，分泌粘狀物，借以牢固地粘附在宿主的表面，此即附著胞。在其上再形成針狀感染菌

18、絲，以宿主的表面，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(zhì)表皮而吸取養(yǎng)料。侵入宿主的角質(zhì)表皮而吸取養(yǎng)料。 (5)附著枝附著枝(adhesive branch) 若干寄生真菌由菌絲細胞生出若干寄生真菌由菌絲細胞生出12個細胞的短枝，將菌絲附著于宿主體上，個細胞的短枝，將菌絲附著于宿主體上，（6）菌核（）菌核（sclerotium) 是一種形狀、大小不一的是一種形狀、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，大的如茯苓力。菌核形狀有大有小，大的如茯苓(大如小孩頭大如小孩頭)，小的如油菜菌核小的如油菜菌核

19、(形如鼠糞）。菌核的外層色深、堅形如鼠糞）。菌核的外層色深、堅硬、內(nèi)層疏松，大多呈白色。硬、內(nèi)層疏松，大多呈白色。（7）菌索（）一般由傘菌等產(chǎn)生，為白色根狀菌）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)。?？稍诟嗟臉淦は潞偷叵掳l(fā)現(xiàn)。 (8)菌環(huán)菌環(huán)(loop )和菌網(wǎng)和菌網(wǎng)( net) 捕蟲菌目捕蟲菌目(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，然后進菌絲組織，用以捕捉線蟲或其他

20、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(nèi)，吸一步從這類環(huán)或網(wǎng)上生出菌絲侵入線蟲等體內(nèi)，吸收養(yǎng)料收養(yǎng)料（9）子實體（）子實體（fruiting body，sporocarp， fructification）Colonial growthHyphal tip growth allows fungi to extend into new regions from a point source or inoculum(接種物接種物). Older parts of the hyphae are often emptied of contents as the cytoplasm is

21、taken forwards with the growing tip. (老的菌絲通常缺乏內(nèi)含物，因為細胞質(zhì)流向生長老的菌絲通常缺乏內(nèi)含物，因為細胞質(zhì)流向生長點點)This creates the radiating colonial pattern seen on agar plates , in ringworm infections of skin and fairy rings in grass lawns. Only hyphal tips contribute to extension growth. However older hyphae can grow aerially

22、or differentiate to produce sporing structures（只（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(jié)構(gòu)）子的結(jié)構(gòu)）Mycelium in agarAgar Surface myceliumKinetics of growth Fungal growth in a given medium follows the growth phases of lag, acceleration, exponential, linear, retardation, statio

23、nary and decline（延遲期、加速期、指數(shù)期、直線期、減速期、穩(wěn)定期、衰亡（延遲期、加速期、指數(shù)期、直線期、減速期、穩(wěn)定期、衰亡期）期） .Exponential growth occurs only for a brief period as hyphae branches initiated, and then the new hypha extends at a linear rate into uncolonized regions of substrate. Life cycles All fungi are characterized by having a perio

24、d of vegetative growth where their biomass increases. The length of time and the amount of biomass needed before sporulation can occur varies. Almost all fungi reproduce by the production of spores, but a few have lost all sporing structures and are referred to as mycelia sterilia(不育不育菌絲體菌絲體). Diffe

25、rent types of spore are produced in different parts of the life cycle.Reproduction in fungiAll fungi undergo a period of vegetative growth where their mycelium exploits a substrate. This stage is followed by asexual and sexual reproduction. There are two conflicting requirements fungi have for their

26、 spores. Spores must allow fungi to spread, but they must also allow them to survive adverse condi-tions. These requirements are met by different types of spores. Small, light spores are carried furthest from parent mycelium in air and these are the dispersal spores（釋放型孢子）（釋放型孢子）. They are usually t

27、he products of asexual sporulation, the sporangiospores and the conidiospores, and so spread genetically identical individuals as widely as possible. Genetic diversity is maintained by sexual reproduction, and the spore products are often large resting spores（休眠孢子）（休眠孢子） that withstand adverse condi

28、tions but remain close to their site of formation. Spores therefore vary greatly is size, shape and ornamentation, and this variation reflects specialization of purpose. Fungal spores：spores allow fungi to spread, to maintain genetic diversity and to survive adverse conditionsReproduction in fungi s

29、pore discharge ：Spores that have a dispersal function can be released from their parent mycelium by active or passive mechanisms . As many spores are wind dispersed, they are produced in dry friable masses which are passively discharged by wind. Other spores are passively discharged by water droplet

30、s splashing spores away from parent mycelium. Spores may be discharged from parent mycelium by passive or active means. Passive mechanisms include using wind and water as dispersants;active mechanisms use explosive principles.Fungal spore discharge Spores in the atmosphere（air-borne fungal spores） c

31、an be carried great distances。Their presence in the air can have impact on human health as they can cause allergic rhinitus （hay fever）and asthma。 Many plant diseases that cause great economic losses are air borne。can affect human, animal and plant health. They can cause allergies and spread plant d

32、isease.Air sporaFungi reproduce by the formation of sexual or asexual spores Asexual reproductionfission ArthrosporeBudding blastosporeOther asexual spore Zoospore Chlamydospore Sporangiospore conidiospora Sexual reproduction Oospore Zygospore Ascospore Basidiospore節(jié)孢子節(jié)孢子(arthrospore)某些真菌生長到一定階某些真菌生

33、長到一定階段，菌絲中間形成許多段，菌絲中間形成許多隔膜，接著從隔膜處斷隔膜，接著從隔膜處斷裂成許多竹節(jié)似的無性裂成許多竹節(jié)似的無性孢子，稱為節(jié)孢子，也孢子，稱為節(jié)孢子，也稱為粉孢子。最典型的稱為粉孢子。最典型的例于是白地霉例于是白地霉(Geotrichumcandidum).arthrosporeBlastospore (芽孢子芽孢子) 這和酵母菌的出芽這和酵母菌的出芽一樣，它是由母細胞生一樣，它是由母細胞生芽而形成的。當(dāng)芽長到芽而形成的。當(dāng)芽長到正常大小時，脫離母細正常大小時，脫離母細胞，或仍連在母細胞上。胞，或仍連在母細胞上。如玉蜀黍黑粉菌如玉蜀黍黑粉菌(Ustilago maydis)能

34、產(chǎn)生芽孢子。某些毛能產(chǎn)生芽孢子。某些毛霉或根霉在液體培養(yǎng)基霉或根霉在液體培養(yǎng)基中形成的被稱為酵母型中形成的被稱為酵母型細胞，也屬芽孢子。細胞，也屬芽孢子。 又稱厚壁孢子或厚膜孢子。某又稱厚壁孢子或厚膜孢子。某些真菌生長到些真菌生長到定階段，在菌絲的定階段，在菌絲的頂端或中間有部分細胞的細胞質(zhì)密頂端或中間有部分細胞的細胞質(zhì)密集在一起，變圓，然后在其四周生集在一起，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。例如總狀外界不良的環(huán)境條件。例如總狀毛霉毛霉(Mucor racemosus

35、)往往在菌往往在菌絲中間形成許多厚垣孢子絲中間形成許多厚垣孢子schlamydospore（厚垣孢子）（厚垣孢子） 無性繁殖產(chǎn)生的孢子在孢子囊無性繁殖產(chǎn)生的孢子在孢子囊(Sporange)(Sporange)內(nèi)內(nèi), ,孢子囊一般孢子囊一般生在氣生菌絲的頂端或生在孢囊梗生在氣生菌絲的頂端或生在孢囊梗(sporangiophore)(sporangiophore)的頂端。的頂端。在形成孢子囊前，首先有多核的原生質(zhì)密集于此處，使其膨在形成孢子囊前，首先有多核的原生質(zhì)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，然后其中原生大，并在下方生出橫隔，形成圓形的囊狀物，然后其中原生質(zhì)體割裂成許多

36、小塊，每質(zhì)體割裂成許多小塊，每塊發(fā)育成為塊發(fā)育成為個孢子囊孢子。因個孢子囊孢子。因而每一而每一個孢子囊所含有的孢子的數(shù)個孢子囊所含有的孢子的數(shù)般都相當(dāng)多。般都相當(dāng)多。 就孢子囊孢子而言就孢子囊孢子而言,般有二類般有二類, ,一種具有一種具有根或根或2323根根鞭毛，能夠游動，所以稱游動孢子鞭毛，能夠游動，所以稱游動孢子(zoospore)(zoospore)。例如腐霉。例如腐霉( (即即thium)thium)。另一種無鞭毛，不能游動，又稱靜止擔(dān)于。另一種無鞭毛，不能游動，又稱靜止擔(dān)于。sporangiospore (孢子囊孢子孢子囊孢子)游動孢子游動孢子 conidium (分生孢子分生孢子

37、) 分生孢子的形成方法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(fù)形成一串孢子。這樣形成的分生孢子，頂端的最此重復(fù)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。老。曲霉屬和青霉屆的分生孢子形成，即屬于此類型。 另一種是在第另一種是在第個分生孢子形成時，柄個分生孢子形成時，柄的長度已達到最高，由第一個分生孢子頂端生的長度已達到最高，由第一個分生孢子頂端生長出第二個分生孢子，如此重復(fù)形成一串

38、孢子。長出第二個分生孢子，如此重復(fù)形成一串孢子。這樣形成的分生孢子，下部的最老。如枝孢霉這樣形成的分生孢子，下部的最老。如枝孢霉屬屬(Cladosporium)(Cladosporium)的分生孢子形成即屬于此類的分生孢子形成即屬于此類型。型。Plastic kitchen cutting board surface - rod bacteria in a smooth matrix; filamentous bacteria ( 絲狀菌絲狀菌 ) -smooth oval cells; fungal hyphae ( 真菌菌絲真菌菌絲 ) with textured spores ( 結(jié)構(gòu)孢

39、子結(jié)構(gòu)孢子 ) (x 2,270)conidiumZoospore（游動孢子）（游動孢子）Asexual spore， usually produced by fungi living in water .Motile zoospores in motile sporangia differentiated from swelled hyphal tips have a single posterior flagellum。The structure of the flagellum is 9+2 ，some has two flagella. 霉菌的有性繁殖是經(jīng)過不霉菌的有性繁殖是經(jīng)過不同性

40、別的細胞結(jié)合同性別的細胞結(jié)合( (質(zhì)配和質(zhì)配和核配核配) )后，產(chǎn)生一定形態(tài)的后，產(chǎn)生一定形態(tài)的孢子來實現(xiàn)的，這種孢子孢子來實現(xiàn)的，這種孢子稱為有性孢子。繁殖過程稱為有性孢子。繁殖過程可分為三個階段：第可分為三個階段：第個個階段為質(zhì)配；第二個階段為質(zhì)配；第二個階段為核配，產(chǎn)生二倍體階段為核配，產(chǎn)生二倍體的核；第三個階段是減數(shù)的核；第三個階段是減數(shù)分裂，恢復(fù)核的單倍體狀分裂，恢復(fù)核的單倍體狀態(tài)。大多數(shù)真菌菌體是單態(tài)。大多數(shù)真菌菌體是單倍體的。有性孢子通常有倍體的。有性孢子通常有下列幾種：下列幾種：Sexual reproduction 菌絲分為雄器菌絲分為雄器(antheridium)(anth

41、eridium)和藏卵和藏卵器器(oogonium)(oogonium)。藏卵器。藏卵器中有一個或數(shù)個卵球中有一個或數(shù)個卵球(oosphere)(oosphere)。當(dāng)雄器和。當(dāng)雄器和藏卵器相配時，雄器中藏卵器相配時，雄器中細胞質(zhì)與細胞核，通過細胞質(zhì)與細胞核，通過受精管而進入藏卵器，受精管而進入藏卵器，與卵球結(jié)合形成卵孢子。與卵球結(jié)合形成卵孢子。圖所示是德巴利腐霉的圖所示是德巴利腐霉的卵孢子的形成。卵孢子的形成。 oospore (卵孢子卵孢子) （b b）同宗結(jié)合）同宗結(jié)合（a a）異宗結(jié)合）異宗結(jié)合根霉的接合孢子根霉的接合孢子Zygospore（接合孢子）（接合孢子）ascospore （

42、子囊孢子）（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18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cleistothecium Sexual reproduction in this group occurs after somatic fusion of different mating-type mycelia. A transient diploid phase is rapidly followed by the formation

43、 of ascospores within sac-shaped asci differentiated from modified hyphal tips. In the initial stages of ascal development hooked hyphal tips form, called croziers （產(chǎn)囊絲鉤）（產(chǎn)囊絲鉤）or shepherds crooks（牧羊杖）（牧羊杖） because of their shape. They have distinctive septae at their base which insure that two diffe

44、rent mating-type nuclei are main-tained in the terminal cell. Formation of the septae is coordinated with nuclear division . In yeasts all these events occur within one cell, after fusion of two mating-type cells, the whole cell being converted into an ascus.The formation of ascosporesSexual reprodu

45、ction in the ascomycetes In more complex Ascomycetes many asci form together, creating a fertile tissue called a hymenium（叫子實層的能育組織）（叫子實層的能育組織）. In some groups the hymeniumcan be supported or even enclosed by large amounts of vegetative mycelium. The whole structure is called a fruit body or sporoca

46、rp（子囊果）（子囊果） and is used as a major taxonomic feature . They can become large enough to be seen with the naked eye. Flask-shaped sexual reproductive bodies are called perithecia, cup-shaped bodies are called apothecia and closed bodies are called cleistothecia. These structures have evolved to prote

47、ct the asci in spore dispersal， but the hymenium itself is unafected by the presence of water。The formation of sporocarp and its formsCup-shaped apotheciumFlask-shaped peritheciumClosed cleistotheciumAsci Asci Ascus containing ascosporesBasidiomycete fungi rarely reproduce asexually. Sexual reproduc

48、tion is by the formation of basidiospores on the gills or pores of large fruit group of fungi are characterized by the most complex and large structures found in the fungi. They are also distinctive in that they very rarely produce asexual spores. Much of the life cycle is spent as vegetative myceli

49、um, exploiting complex substrates. A preliminary requisite for the onset of sexual reproduction is the acquisition of two mating types of nuclei by the fusion of compatible hyphae. Single representatives of the two mating-type nuclei are held within every hyphal compartment for extended periods of t

50、ime. This is termed a dikaryotic state（雙核期）（雙核期）, and its maintenance requires elaborate septum formation during growth and nuclear division .Basidiospore Onset of sexual-spore formation is triggered by environmental conditions and begins with the formation of a fruit body primordium（子實體原基）（子實體原基）.

51、Dikaryotic mycelium（雙核菌絲體）（雙核菌絲體） expands and differentiates to form the large fruit bodies we recognize as mushrooms and toadstools（毒（毒蕈）蕈）. Diploid formation and meiosis occur within a modified hyphal tip called a basidium 。Basidium formation 核融合核融合Nuclear fusion減數(shù)分裂減數(shù)分裂meiosis 擔(dān)孢子梗擔(dān)孢子梗sterigmataB

52、asidiospores擔(dān)孢子擔(dān)孢子Basidium（擔(dān)子）（擔(dān)子）Basidium and basidiospore formationFour spores are budded from the basidium. Basidia form together to create a hymenium which is highly sensitive to the presence of free water. The hym-enium is distributed over sterile, dikaryotic supporting tissues which protect it

53、 from rain. The hymenium can be exposed on gills or pores beneath the fruit body, seen in the toadstools and bracket fungi, or enclosed within chambers as in the puffballs and truffles Formation of basidiosporepuffball （馬勃）Bracket（檐狀傘）（檐狀傘） Toadstool（毒蘑菇）（毒蘑菇）Hymenenium（子實層）（子實層）Structure of sexual

54、sporocarps in the basidiomycetesbasidiospore（擔(dān)孢子）（擔(dān)孢子）擔(dān)孢子是擔(dān)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(dān)子上，所以稱為擔(dān)孢子。典型的擔(dān)子菌的擔(dān)子上有四個擔(dān)孢子。各種擔(dān)孢子的形狀及表面特征各種擔(dān)孢子的形狀及表面特征Food related molds1. Aspergillus 曲霉屬曲霉屬 2. penicillium（青霉屬（青霉屬 ）3. Rhizopus （根霉屬）（根霉屬）4. sporotrichum (側(cè)孢霉屬側(cè)孢霉屬)5. Thamnidium(枝霉屬枝霉屬)6. Alternaria（交鏈孢屬

55、）（交鏈孢屬）7.Botrytis （葡萄孢霉）（葡萄孢霉）（木霉屬）（木霉屬）（紅曲屬）（紅曲屬）（赤霉屬）（赤霉屬） 11.Cordyceps（蟲草屬）（蟲草屬）（地霉屬）（地霉屬）（長蠕孢霉）（長蠕孢霉）food related MouldsAspergillus曲霉屬曲霉屬 分生孢子 初生小梗孢子穗 小梗 次生小梗 頂囊 足細胞 Conidia primary sterigmaconidial head sterigme secondary sterigma Vesicle foot cellMorphology of Conidial head is the basis for sp

56、ecies identification孢子穗的形態(tài)是菌種鑒定的依據(jù)孢子穗的形態(tài)是菌種鑒定的依據(jù)Aspergillus Relationship with foodbeneficialFermentation industry soy sauce釀醬釀醬 vinegar制醋曲制醋曲 fermented bean curd腐乳腐乳 alcohol beverage釀酒釀酒Food processing organic acid有機酸有機酸 enzyme 酶制劑酶制劑 淀粉酶淀粉酶 蛋白酶蛋白酶 果膠酶等果膠酶等Relationship with foodharmful Usually distr

57、ibuted on the surface of following foodstuff：Cakes、fruits、vegetables、meat、 grain and other organic objects。Causing following consequences：Go mouldy；become mildewedProduce or secrete carcinogenic substance（blastomogen）致癌物）致癌物質(zhì)質(zhì)eg 。 aflatoxin（黃曲霉毒素）（黃曲霉毒素）Food related moldspenicillium（青霉屬（青霉屬 ） 十分接近于曲

58、霉，在自然界分布很廣，長生長在腐爛的柑十分接近于曲霉，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(zhì)，但也用來生產(chǎn)青橘皮上，呈青綠色，不少種類引起食品變質(zhì)，但也用來生產(chǎn)青霉素和有機酸等。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(jié)構(gòu)也不同。青霉菌菌絲與曲霉相似，但無足細胞，孢子穗結(jié)構(gòu)也不同。其分生孢子梗頂端不膨大，而是經(jīng)過多次分枝產(chǎn)生幾輪對稱或其分生孢子梗頂端不膨大，而是經(jīng)過多次分枝產(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

59、形，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。一般呈藍綠色。 Plastic kitchen cutting board surface - rod bacteria in a smooth matrix; filamentous bacteria ( 絲狀菌絲狀菌 ) -smooth oval cells; fungal hyphae ( 真菌菌絲真菌菌絲 ) with textured spores ( 結(jié)構(gòu)結(jié)構(gòu)孢子孢子 ) (x 2,270)根霉在自然界分布廣泛，經(jīng)常出現(xiàn)在淀粉質(zhì)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

60、根霉。此外，根霉也可以用來生產(chǎn)有機酸等其它物質(zhì)。Food related moldsRhizopus （根霉屬）（根霉屬）Rhizoid假根假根Stolen匍匐絲匍匐絲 sporangeUaually blacksporangiophore 菌絲分隔菌絲分隔分生孢子梗分枝，頂端產(chǎn)生分生孢子。分生孢分生孢子梗分枝，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，為干燥粉末狀。子單細胞，梨形。菌落呈奶油色澤，時間長后，為干燥粉末狀。已經(jīng)報告該菌能在已經(jīng)報告該菌能在OCOC以下生長，常在冷藏肉中形成白色以下生長，常在冷藏肉中形成白色斑點。斑點。 food related molds