The Eukaryotes: Fungi, Algae, & Protozoa(Chapter 12)Lecture MaterialsforAmy Warenda Czura, Ph.D.Suffolk County Community CollegeEastern CampusPrimary Source for figures and content:Tortora, G.J. Microbiology An Introduction 8th, 9th, 10th ed. San Francisco: PearsonBenjamin Cummings, 2004, 2007, 2010.-50% of world population infected with eukaryotic pathogensTwo microbial kingdoms:1. Fungi2. ProtistaSubkingdomsA. Protozoa (animal-like)B. Algae (plant-like)Kingdom Fungimycology = study of fungicommon characteristics of fungi:1. all are chemoheterotrophs2. most are saprophytes3. most are aerobic or facultatively anaerobic4. few are human pathogens5. cell walls are composed of chitinOrganized into three general groups based onshape:1. Molds and Fleshy Fungi-consist of long filaments of cells joined endto end = hyphae-hyphae can be one of two structural types (genetically determined for a particular fungus):1. Septate Hyphae-joined cells have distinct separations called septa2. Coenocytic Hyphae-hypahe consists of fused cells-hyphae grow by extension at the tip-a mass of hyphae is called a mycelium-a mold mycelium will produce two differentversions of its hyphae:1. vegetative hyphae-grow flat along surfaces-used to obtain nutrients2. aerial hyphae-stick up off the mycelium-used to produce sporesfor reproductionAmy Warenda Czura, Ph.D.1SCCC BIO244 Chapter 12 Lecture Notes2. Yeasts-nonfilamentous, unicellular, ovaloid-all are facultative anaerobes-in absence of oxygen will ferment carbohydrates into alcohol & carbon dioxideA. Budding Yeasts-divide by producingoutgrowth called a bud-bud will enlarge and separate from mother cell following mitosis-if bud fails to separate = pseudohyphae(not true hyphae like molds:hyphae = cells tightly attached by shared walls, cytoplasm joined by porespseudohyphae = daughters remain stuck but no shared walls or cytoplasm)B. Fission Yeasts-divide by mother cell elongating and undergoing mitosis-daughter cells separated by formation of a septa in the center (fission)3. Dimorphic Fungi-can grow in multicellular mold-like hyphal form or unicellular yeast-like ovaloid formdepending on conditionse.g. Candida albicans25°C, acid pH = yeast37°C, neutral pH = hyphaeLife cycle of fungi-fungi can reproduce asexually by:1. fragmentation of hyphae (mold), budding (budding yeast) or fission (fission yeast)2. asexual spores-fungi can reproduce sexually by the formation of sporesspores are formed on the ends of aerial hyphae(not endospores: reproductive, outside cell)-asexual spores:-form on the hyphae of one organism-germinate to form exact clones of theparent-sexual spores:-form after the fusion of two haploid nuclei from opposite mating type cells of the same species-when spore geminates it has characteristics of both parents-sexual reproduction is NOT common in fungiAsexual Spores-produced by mitosis and cell division-contain DNA that is exact copy of parent1. Sporangiospore-spores form in sac called sporangium-sporangium forms at end of aerial hyphae called a sporangiophore-hundreds of sporangiospores in a single sporangiumsporangiophoresporangiumAmy Warenda Czura, Ph.D.2SCCC BIO244 Chapter 12 Lecture Notes2. Conidiospore-spores produced at the end of an aerial hyphae called a conidiophore-most common type:Conidia: chains of conidiospores on conidiophoreSexual Spores-formed by fusion of two haploid nuclei intosingle diploid zygote-zygote then undergoes meiosis to generate haploid spores (usually multiples of four)1. Zygospores-one thick spore betweentwo parent hyphae2. Ascospores-four spores in a sac calledan ascus,at the end ofone hyphae3. Basidiospores-four spores on the end ofa basidiumFungi organized into three Phyla based on thetype of sexual spore:1. Zygomycota (conjugation fungi: molds)-coenocytic hyphae-asexual spore = sporangiospores-sexual spore = zygosporese.g. Rhizopus (common bread mold)2. Ascomycota (sac fungi: yeasts and molds)-septate hyphae-asexual spores = conidiospores-sexual spores = ascosporese.g. Aspergillus (black house mold)Saccharomyces (bread and beer yeast)Amy Warenda Czura, Ph.D.3SCCC BIO244 Chapter 12 Lecture Notes3. Basidiomycota (club fungi: mushrooms)-septate hyphae-asexual spores = conidiospores-sexual spores = basidiosporesAnamorphs - fungi that have lost ability to reproduce sexually; DNA sequence analysisused to assign phylume.g. Penicillium (green fruit mold)Fungi differ from bacteria:-grow in acidic environments (pH 5)-resistant to osmotic pressure-grow in low moisture-require less nitrogen-can metabolize complex carbohydratesFungal Disease-few fungi are pathogens-if pathogenic, tend to be opportunistic pathogens (only cause disease in immuno-compromised host)mycosis = fungal infection: can range superficial (skin) to systemic (blood,organs)Most are chronic due to slow growth and difficultly in treatingLichens-combination of green algae and fungus-classified by fungus species-the two organisms exist in mutualistic relationship: both benefit-algae: photosynthesis tosynthesize organics tofeed both-fungi: holdfast, &protection fromdesiccation-together can survive in environments whereneither would survive alone-often first and only life forms to colonize newly exposed rock, slow growing-lichens (fungal part) degrade rock to producesoil for plants-lichen serves as food for animalsFungi and SocietyThe good:-recycle vital nutrients: compost-aid plant growth-food and beverage production-vaccine production-drug production-biological control of pests-lichens:air quality testingdyes and pH indicator litmusThe bad:-food spoilage-crop death-human pathogensnosocomial infectionsimmunocompromised patientsrespiratory illnessAmy Warenda Czura, Ph.D.4SCCC BIO244 Chapter 12 Lecture NotesKingdom ProtistaSubkingdom Algae-plant-like protistsCommon features of algae:1. most have cellulose walls2. carry out oxygenic photosynthesis using chlorophyll a in chloroplasts3. require high moisture4. are photoautotrophs5. unicellular or multicellular (colonial or filamentous, no tissues)6. reproduce sexually and asexuallyFive Phyla/Divisions:1. Brown algae-dark brown pigment & chlorophyll a + c-cellulose walls-non motile, multicellular-produce algin-food storage as mannitole.g. seaweed2. Red algae-red pigment & chlorophyll a + d-cellulose walls-non motile, multicellular-produce agar-food storage as starche.g. seaweed3. Green algae-cellulose walls, chlorophyll a + b-flagellated or filamentous-unicellular or multicellular-food storage as starche.g. “pond