MOST FUNGI ARE DECOMPOSERS • FUNGI ABSORB MATERIALS FROM THE ENVIRONMENT • INCLUDE MUSHROOMS, MOLDS, & YEAST • CAN BE HELPFUL OR HARMFUL TO OTHER ORGANISMS Absorb Material• from Environ. Typical fungus made of • Most are decomposers reproductive body & that absorb nutrients network of cells forming & leave behind threadlike hyphae (one simpler compounds. cell thick). A mass of • Are heterotrophs (get hyphae form a mycelium. energy from living or The cells release once living matter). chemicals, digesting • They and bacteria surrounding materials & decompose leaves, absorbing nutrients. shed skin, animal • Fungi reproduce sexually droppings, etc. (with spores) or • Except for yeast, most asexually. Spore = one fungi are reproductive cell that can multicellular. grow into new fungus. Absorb Material from Environ. • A single mushroom can make a billion spores. • Spores are released into air & spread by wind long distances. • Some spore have tough coverings protecting them for years until conditions are right for growing. • Fungi can reproduce asexually when hyphae break off to form anew mycelium. Yeast (single cell fungi) reproduce by cell division, budding & spores. Mushrooms, Molds & Yeast • One mushroom may be from a mycelium that fills the size of a football field. • Some mushrooms are poisonous & some edible. The cap is where spores are made, and hyphae fill the cap & stalk. • MOLDS: fuzzy growth sometimes seen on food; hyphae grow into food & digest it as they grow. • Some Penicillium mold are used in Brie & blue cheese. Some aspergillus mold is used in soy sauce. Trichoderma mold grows in soil & makes digestive chemicals used to give blue jeans a stonewashed look. • Mushrooms, Mold, & Yeast Molds may cause disease. Fungal molds cause athlete’s foot; others affect plants (Dutch elm); Penicillin is an antibiotic from Penicillium fungus. • Molds reproduce via spores mostly carried by air; the “hat thrower” fungus Pilobolus grows in animal droppings & shoots off its spore cap via water pressure to land a few feet away to hopefully be eaten in the grass by a cow. Mushrooms, Molds & Yeast • Yeasts are single celled fungi. Grow in moist environments (plant sap, skin, shower curtains) • If yeast growing on human skin reproduces too rapidly, it may cause disease. • Used in food products (breaks down sugars making CO2 gas to make bread rise & give wine/beer its bubbles). Fungi can be Helpful or Harmful • Fungi & bacteria are Earth’s decomposers (even live in sea to recycle materials for ocean-living organisms). • Hyphae grow into & decompose other organisms material (to turn dead tree back into useful nutrient rich soil or to kill off Dutch elm) • Most hyphae surround plant roots providing nutrients for plant, while plant provides food. • Lichen = fungal hyphae mixed around single celled algae. Lichen live in arctic & desert, even bare rock, eventually breaking it down into soil. Helpful/Harmful Fungi • May make toxins (In 1845 fungus infected Ireland’s potato crop, dropping causing Ireland to go from 8 million to 4 million people; many died of disease, starvation and others left, many to US. Today, many banana crops are being destroyed by fungal disease. • Penicillin from a fungal toxin kills off many types of bacteria, so is used as an antibiotic.