2Five kingdom system of classifying living things showing that both fungi and animals may have evolved from a common ancestor
3Mycology Mycology is the study of fungi which includes yeast and molds They are eukaryotic and are chemo-heterotrophs (require organic compounds for energy and a carbon source)Most have a cell wall of chitinMolds are made of long filaments called hyphaeIf there are cross walls that divide the hyphae into uninucleate units the hyphae are septate hyphaeIf there are no cross walls, the hyphae are called non-septate or coenocytic hyphaeWhen the hyphae grow and intertwine to form a mass, they are called mycelium
4Fungi Eukaryotes Chitin cell walls Use organic chemicals for energy. Molds and mushrooms are multicellular consisting of masses of mycelia, which are composed of filaments called hyphae.Yeasts are unicellular.Figure 1.1b
5Fungi are important as pathogens of animals and plants. Over 70% of all plant diseases are caused by fungi
6Mycelium are of three kinds: 1- vegetative mycelium ( penetrates the surface of the medium and absors nutrients2- Aerial mycelium ( grow above the agar surface)3- Fertile mycelium (bear reproductive structure such as conidia or sporangia)
7Yeasts are non-filamentous, unicellular fungi that are oval or spherical in shape. Yeasts reproduce by the process of budding or binary fission.
9Classification Fungi based on there sexual reproduction : Zygomycetes: zygospores, ex. Mucor & RhizopusMucorRhizopus
10MycologyFungi are classified based on the type of sexual spore that they formZygomycotaHave non-septate hypheaHave asexual sporangiosporesForm sexual zygospores. They are large spores enclosed in a thick wall and formed from the fusion of two cells
13Mycology Ascomycota Have septate hyphae Have asexual conidiospores Have sexual ascospores. Ascospores result from the fusion of nuclei of two cells. They are produced in a sac-like structure called an ascus.
18Deuteromycetes: not produce any sexual spores, ex Deuteromycetes: not produce any sexual spores, ex.: Monilia fungi & BotrytisMonilia fungiBotrytis
19Classification Fungi based on morphology: Moulds (Molds): Filamentous fungi Eg. AspergillusYeast : Eg. SaccharomycesYeast like: Similar to yeasts but produce psedohypha Eg. candida albicansDimorphic: Two different morphological form at two different enivormental conditions
20Mycology Dimorphic fungi Some fungi, including most of the pathogenic fungi, exhibit two forms of growth. This is known as dimorphism and the organisms can grow either as a yeast-like form or a mold-like form.Frequently the form that the organism grows as is temperature dependent and at 370 C the organism grows as a yeast-like form and at RT or at 250 C it grows in a mold-like form. CO2 concentration or the presence of serum may also be a determining factor
21Classification Fungi according to nutrion: SaprophyticParasiticSymbiotic or Mycorrhizal
22How do Fungi get their Nutrition? Heterotrophssecrete digestive enzymesabsorb digested material into cellpredatorsparalyzing preyparasitesfeeding on living creaturesdecomposerbreakdown dead remainsfungal cellsplant cell wallplant cell membraneplant cell
24Classification Fungi based on hypha: Septate – Non septate Somatic hyphae. A) Portion of a hypha having more than one nucleus (nonseptate);B) Portion of a septate hypha.
25coenocytic having multiple nuclei embedded in cytoplasm without cross walls; nonseptateCross Walls of HyphaeCoenocytic hyphae where the nucleis of each cell is embedded in the cytoplasm without a cell wallEg. Zygomycota, OomycotaHyphae with cross wallsEg. Basidiomycota, Ascomycota