Sac fungi

These are the most diverse group of fungi with 30,000 species. They produce asexual spores called conidia and sexual ascospores in sac-shaped cells called asci. Multicelled species form reproductive structures called ascocarps that enclose the asci.

Multicelled forms include edible morels and truffles, plus Penicillium, famous as a source of antibiotics, and Aspergillus, the fermenter of soy sauce.

Single-celled yeasts are useful in baking (carbon dioxide production makes the bread "rise") and for alcoholic-beverage production.

Plant Pathogens:

Ascomycetes are responsible for

• Chestnut blight
• Dutch elm disease
• Apple scab

Human Pathogens & Toxins

Ascomycetes cause

• Histoplasmosis
• Valley fever
• Candida ("yeast") infections
• Ringworm
• Athlete's foot
• Ergotism

Claviceps purpurea

• Ascomycete that parasitizes cereal grains and causes ergotism
• Produces alkaloids
• Some have been used medically
• Ingestion causes ergotism (hallucinations, vomiting, diarrhea)

Imperfect Fungi

These are species that have never been observed to form sexual spores. Many do make asexual spores.

They include the strange predatory fungus Arthrobtrys dactyloides, which captures prey in noose-like hyphae.

REVIEW: Yeasts are members of which of the following?
Answer sac fungi