DOH133 Lecture Notes - Lecture 12: Chitin, Facultative Anaerobic Organism, Cell Wall
Identify two beneficial and two harmful effects of fungi
Harmful effects of Fungi
1. Mycoses: Ringworm, athletes foot: caused by ascomycetes Trichophyton
2. Allergies: Sick building syndrome Stachybotrys chartarum
3. Toxin production: Problem for mushroom foragers – death cap
4. Destruction of crops: Rusts, ripe rots; and food storage – Rhizopus;
Penicillin
5. Mycotoxins in food: Aspergillus - produces aflatoxin in peanuts and grains
Types of mycoses (fungal diseases)
1. Systemic mycoses: Deep within body
2. Subcutaneous mycoses: Beneath the skin
3. Cutaneous mycoses: Affect hair, skin, and nails
4. Superficial mycoses: Localized, e.g., hair shafts
5. Opportunistic mycoses: Caused by normal microbiota or environmental
fungi
Distinguishing characteristics of lichens, and nutritional needs
1. A lichen is a mutualistic combination of an photosynthetic microbe (alga or
cyanobacterium) and fungus
2. Alga produces and secretes carbohydrates for fungus
3. Fungus provides holdfast (home for alga that clings to surfaces)
4. You can see lichens on the old, tiled roofs of CSU/OA buildings
5. You can see lichens on the trees on the way to the CSU/OA cellar door
Oomycetes are important fungal-like algae that cause diseases
- For some time Oomycetes (water molds) were thought to be fungi because
they form hyphae. Molecular studies have shown they are more closely
related to brown algae
- They have swimming zoospores, like Chytrids (Chytridiomycota) BUT walls
are cellulose and they have two flagella
- They cause diseases such as late blight of potato. The agent is
Phytophthora infestans; cause of Irish potato famine of 1845. The Irish
population dropped by about 25% due to death (starvation) and
emigration.
- Dieback of Eucalypts & Jarra forests – Phytophthora cinnamomi
- Downy mildew of Grapevines – Plasmopara viticola and other fruit
Document Summary
Identify two beneficial and two harmful effects of fungi. Types of mycoses (fungal diseases: systemic mycoses: deep within body, subcutaneous mycoses: beneath the skin, cutaneous mycoses: affect hair, skin, and nails, superficial mycoses: localized, e. g. , hair shafts, opportunistic mycoses: caused by normal microbiota or environmental fungi. Oomycetes are important fungal-like algae that cause diseases. For some time oomycetes (water molds) were thought to be fungi because they form hyphae. Molecular studies have shown they are more closely related to brown algae. They have swimming zoospores, like chytrids (chytridiomycota) but walls are cellulose and they have two flagella. They cause diseases such as late blight of potato. Phytophthora infestans; cause of irish potato famine of 1845. The irish population dropped by about 25% due to death (starvation) and emigration. Dieback of eucalypts & jarra forests phytophthora cinnamomi. Downy mildew of grapevines plasmopara viticola and other fruit. It is composed of fine tube-like cells called hyphae.
