Eukaryotes: Fungi, Algae, Protozoa 1

Eukaryotic microbes (3 major groups)

• The fungi

• The microscopic algae

• The protozoa

Fungi (Key benefits)

• Ability to decompose dead plants (recycle elements)

• Form symbiotic relationships with plants and help absorb water and nutrients. (mycorrhizae)

• Use in food production and antibiotic prodution

many cause diseases in humans, animals, and plants

Mycology

Study of fungi

Fungi (characteristics)

• Mainly chemoteterotrophs

• Decompose organic matter

• Mainly aerobic or facultative anaerobes.

• Cell wall: Chitin (NO peptidoglycan)

• Spores: sexual and asexual reproduction spores

Fungi (3 main categories)

• Molds

• Yeast

• Fleshy fungi

Molds

• Grow via filaments

• No mushrooms

Yeast

• Unicelluar

Fleshy Fungi

• Grow via filaments mainly

• Make mushrooms, highly visible fruiting bodies.

Vegetative Structures in Fungi

• Thallus: the entire body of an individual

• Hypha (plural: hyphae): individual filaments. When together, they can celled mycelium

Hypha (types)

• Septate hyphae: hyphae contain cross-walls between cells

• Aseptate hyphae: hyphae do not contain septa between cells (multinucleate)

Hypae grow in two types

• Vegetative: They are embedded in the substance (obstaning nutrients are easy)

• Aerial: They have emerged into the air (Generally for reproduction).

Fungal (spores basics)

Reproduction is based on the formation of spores that detach from the parent and germinate into a new mould or fleshy fungi.

Fungal Spores (Asexual Spores)

Are those made via mitosis-type cell division?

• Individual spores go on to make new identical individuals.

Fungal Spores (Sexual spores)

Those made via meiosis-type cell divisions

• Spores make hyphae that can interact and share nuclei. These fuses allow ‘mating’ to increase genetic variation.

Fungal life cycle (sexual)

• Meiosis

• Germination

• Plasmogamy (1 +1)

• Karyogamy (2n)

Types of fungal spores for taxonomic identification

• Conidiospores.

• Arthroconidia spores

• Blastoconidia spores

• Sporangiospores

Conidiospores

Not enclosed in a sac

Arthroconidia spores

Spores are fragmented septate hyphae

Blastoconidia spores

Spores look like buds

Yeast takes on a ‘psueudohypha’ structure

Sporangiospores

Enclosed in a sac.

Flesh fungi (2 groups)

• Basidiommycota

• Ascomycota

Mushroom (Basidiomycota)

• Club fungi

• Make a classic mushroom shape to disperse spores

Mushroom Ascomycota

• Sac Fungi

• Make a ‘mushroom,’ but spores remain in sac-like structures.

Yeast-like fungi (reproduction)

• Budding (divide unevenly)

• Fission (divide evenly)

Dimorphic fungi grow similar to yeast at 37C and mold like at 25C

Growing fungi (in the lab)

• Most molds are aerobic

• Most yeasts are facultative anaerobes

• Fungi can generally metabolize complex carbohydrates.

Mycosis

Fungal infection

Notable pathogenic fungi

• Rhizopus stolonifer (common black bread mold)(pathogenic to many plants)

• Rhizopus mucor (Pathogenic to humans and causes premature tissue death)

• Ammanita phalloides (death cap mushroom) (death for humans)

• Candida albicans (pathogenic yeasts)(infect vairous parts of human body)

Fungi (positive organisms to humans)

• Saccharomycoes cerevisiae (used in bread, wine, and hapatitis B vaccine production

• Lentinula erodes, Pleurotus ostreatus, and Grifola fromdosa (shiitake, oyster, and maitake mushrooms

• Penicillium (used in antibiotic production and discovery)

Microsporidia (Characteristics)

• Closely related to fungi genetically. Once considered types of protists

• Lead to chronic diarrhea

• Obligate intracellular parasite

• Presence of a unique organelle: polar tubule or polar filament (coiled inside and used to invade host cells)