Fungi

• Rhizopus

  
• Aspergillus

  
• Puccinia

  
• Penicillium

  
• Yeast

  
• Mucor

  
• Kingdom Fungi

  Includes around 100,000 species divided into macroscopic (mushrooms, puffballs) and microscopic (molds, yeasts) forms
• Fungal forms

  • Unicellular or colonial
  • Multicellular (like mushrooms)
• Microscopic fungi

  Exhibit yeasts (round to oval cells that bud to reproduce) and hyphae (long, threadlike cells in molds)
• Yeasts


  Can form pseudohyphae from attached buds
• Yeast colonies

  Grow in soft, uniform colonies
• Mold colonies


  Form distinct textures like cottony or velvety mycelium
• Ascomycetes and basidiomycetes


  Form fruiting bodies (e.g., mushrooms) for sexual spore production
• Fungal cell walls

  Primarily contain chitin, resistant to degradation
• Fungi

  Heterotrophic, obtaining nutrients as saprotrophs, parasites, or mutualistic symbionts
• Fungi


  • Thrive in diverse environments, from high salt to extreme temperatures
  • Play significant roles in medicine (causing mycoses) and agriculture (as plant pathogens)
• Fungal reproduction

  Via spores, either sexually or asexually; nonmotile spores are common
• Spores


  Aid in wide distribution, carried by air or adhering to arthropods
• Asexual reproduction

  1. Commonly through spores produced in sporangia or from hyphal cells (conidia)

  2. Some fungi also reproduce asexually via hyphal fragmentation or outgrowth
• Sporangiospores


  Formed inside a sac-like structure called sporangium, attached to a stalk (sporangiophore), released when sporangium ruptures
• Conidia (Conidiospores)


  Free spores not enclosed in a sac, develop by pinching off the tip of a specialized hypha or segmenting from a vegetative hypha
• Types of Conidia

  • Arthrospore
  • Chlamydospore
  • Blastospore
  • Phialospore
  • Microconidium and Macroconidium
  • Porospore
• Sexual reproduction phases

  1. Plasmogamy: Fusion of protoplasts, initiating the process

  2. Karyogamy: Fusion of nuclei, following plasmogamy
• Dikaryotic stage


  In some fungi, nuclei remain separate (dikaryon) after plasmogamy, possibly for months or years, nuclei divide in tandem within dikaryotic mycelium
• Formation of diploid nucleus


  Eventually, nuclei fuse to form a diploid nucleus, diploid nucleus undergoes meiosis swiftly, restoring haploid condition
• Specialized spores

  Resulting from sexual reproduction: zygospores (in zygomycetes), ascospores (in ascomycetes), and basidiospores (in basidiomycetes)
• Chytridiomycota (The Chytrids)


  Predominantly aquatic fungi, approximately 790 species known, found in diverse environments including soils of ditches, pond banks, desert soils, and in the rumens of large herbivorous mammals
• Chytridiomycota


  • Contains chitin in cell walls, stores glycogen
  • Typically coenocytic (multi-nucleate) with few septa
  • Motile cells with a single posterior whiplash flagellum (zoospores and gametes)
  • Some are unicellular without a mycelium, transforming into reproductive structures, others have rhizoids for substrate anchorage
  • Parasitic chytrids target algae, protozoa, aquatic oomycetes, and plant spores/pollen, some species are saprophytic, feeding on dead insects and organic matter
• Zygomycota (The Zygomycetes)


  Approximately 1060 species found in decaying plant and animal matter, as parasites, or in symbiotic relationships (endomycorrhizae), have coenocytic hyphae with rapid cytoplasmic streaming, some exhibit yeast-like growth
• Asexual reproduction in Zygomycota


  Common via haploid spores in specialized sporangia on hyphae
• Rhizopus stolonifer


  • Well-known zygomycete forming black mold on moist, carbohydrate-rich foods, significant pest of stored vegetables and fruits
• Rhizopus stolonifer mycelium

  Includes coenocytic hyphae, stolons with rhizoids, and sporangiophores producing spherical sporangia
• Sexual reproduction in Zygomycota

  Involves formation of zygospores within zygosporangia after plasmogamy and karyogamy between + and - strains, zygospores remain dormant until germination and undergo meiosis for asexual reproduction
• Uses of Zygomycota

  • Species like Rhizopus used in Indonesian tempeh production to enhance soybean nutritional value, other species utilized in pharmaceuticals, industrial processes, and food production (e.g., sufu, margarine coloring)
• Basidiomycota (The Club Fungi)


  Includes mushrooms, puffballs, toadstools, and rusts, have a club-shaped structure called a basidium involved in sexual reproduction, have septate mycelium with perforated septa, transition through monokaryotic and dikaryotic phases
• Primary mycelium in Basidiomycota


  Develops from germinating basidiospores, dikaryotic mycelium forms from fusion of monokaryotic hyphae
• Basidiomata (Basidiocarps)


  Fleshy, spore-producing bodies like mushrooms and puffballs
• Basidiomycota


  • Majority decompose plant debris such as cellulose and lignin
  • Many mushrooms globally consumed, e.g. Agaricus campestris cultivated
  • Some produce alkaloids (e.g. Amanita phalloides), rusts and smuts damage cereal crops
• Classes of Basidiomycota

  • Basidiomycetes (mushrooms, shelf fungi)
  • Teliomycetes (rusts)
  • Ustomycetes (smuts)
• Sexual reproduction in Basidiomycota

  Begins with spore germination, leading to monokaryotic mycelium, mating types form dikaryotic mycelium, meiosis in basidia produces haploid basidiospores on sterigmata