A Kingdom of its Own Fungi

What are Fungi Eukaryotic organisms Some fungi look like plants (i.e. mushrooms), but they are not.

Few types are unicellular (E.g. Saccharomyces cerevisiae aka yeast)

Most are multi-cellular

Structure Adapted for two main functions Absorption of nutrients Reproduction The bodies of multi-cellular fungi are made up of a thin thread of cells called hyphae (string is called hypha) A network or branching hyphae are called a mycelium Mycelium - network of hyphae

Reproductive Structures Mycelium – branching network of hyphae

How Fungi Feed Most fungi are saprophytes – feed on dead or decaying matter As fungi hyphae grow across a food source, they release enzymes (proteins) outside the cell to help break down the source into smaller molecules – Extracellular digestion The larger the surface area the mycelium occupies, the greater the amount of nutrients absorbed

Fairy Circle

Some fungi are parasites of plants and animals and can cause diseases such as Athlete’s foot (Epidermophyton floccosum) and ringworm (Microsporum). Parasitic fungi are specialized to feed on living cells There have hyphae called haustoria that can penetrate host cells without immediately killing them

Cordyceps Fungus

Symbiotic Fungi Most fungi live in symbiosis with plants and animals – live to benefit both organisms Symbiotic relationship: a relationship between two organisms in which both partners benefit from the interaction.

Symbiotic Fungi Example: Mycorrhiza relationship – mycelium of fungi grows around plant roots, absorbing nutrients from the soil and releasing it into the roots The fungi absorbs nutrients like sugars and amino acids from the plant in exchange

Uses of Fungi Fungi are used in everyday things: all the citric acid used in soft drinks, candies, artificial lemon juice, and baked goods is produced industrially by fungus fermentation using Aspergillus niger

Saccharomyces cereviseae is used in fermentation processes that result in the production of beers, wines and spirits

Other fungi provide numerous drugs (such as penicillin and other antibiotics), foods like mushrooms, truffles and morels

Reproduction Most Fungi have both asexual and sexual methods of reproduction The simplest form of asexual reproduction is by fragmentation Pieces of hyphae are broken off and grow into a new mycelium.

Reproduction Most fungi live on land. To disperse themselves, Sporangia (reproductive structure) release spores in great numbers Spores: Lightweight reproductive cells Spores are easily transported on bodies of insects, birds or by the wind Spores can grow directly into a new organism in a suitable environment Spores can be sexual or asexual

Classifying Fungi At one time, fungi were included with plants Now they have their own kingdom with four subgroups

Deuteromycota Basidiomycota Ascomycota Zygomycota (Imperfect Fungi) 20,000 species Basidiomycota Club Fungi 25,000 species Ascomycota Sac Fungi 30,000 species Zygomycota Zygospore Fungi 1,500 species

Famous Fungi – Bitter Oyster

Famous Fungi – Anemone Stinkhorn

Famous Fungi – Bleeding Tooth

Famous Fungi - Psilocybin

Famous Fungi – Amanita muscaria

Famous Fungi – Death Cap

Textbook Q’s PG. 458 #1, 2, 4, 5, 6