Kingdom Fungi (ch. 26)If at first you don’t like a fungus …

Just wait a little, It will grow on you.

Mycology = study of fungiGeneral Characteristics of Fungi

Classification into Phyla / Divisions based on Sexual Reproductive StructuresEffects on Humans – Diseases & Benefits

* You should know all examples *

General Characteristics of Fungi• Heterotrophic saprophytes

(decomposers) release / recycle inorganic nutrients

• Reproduce mostly asexually• Haplontic life style – grow from haploid

spores• May also be parasitic, predatory, or form

other symbioses

General Characteristics of Fungi• Secrete digestive enzymes onto food extracellular digestion absorption of nutrients

• Digestive enzymes can digest tough substances, such as cellulose in wood

• Cell walls made of chitin, a polysaccharide

• Multicellular, except for yeasts (unicellular)

• Very efficient nutrient transport in hyphae grow very fast!

• Most are poisonous leave it to the experts to pick the fungus on your plate…

Important Symbioses

Lichen = alga or cyanobacteria + fungus–> soil formation from rock

Mycorrhyzae provide plant roots w/ inorganic nutrients, receive sugars

Fungal Structure - Cells

• Hypha = multinucleated, filamentous cell

Nuclei

Septate hyphae (septum = dividing wall) Coenocytic hyphae

(no septa)

Nuclei

Cell walls made of chitin

Fragmentation (asexual): new fungus grows from fragment

↓

Fungal Structure - Body• Mycelium = network of hyphae body of

fungusFruiting body to disperse spores

Hyphae

Mycelium

Myceliumof fungus on

wood

“Fairy Rings” are mushrooms (fruiting bodies) that grow at the tips of an underground mycelium:

Generalized Fungal Life Cycle

Sporulation

Diploid Spore Producing Structure:Meiosis (2n n)

Haploid Spore Producing Structure:Mitosis (n n) /Dikaryotic

n

nRECOMBINATION:

GENETIC DIVERSITY

Sporulation

SPEED: MAKE SPORES FAST!

n + n 2n

2n

Basidiomycota “Club Fungi”

Basidiomycetes , Ernst Haeckel,

1904

Phylum Basidiomycota“Club” Fungi*

Asexual reproduction:

fragmentation of septate hyphae and

asexual spores

*Basidium = Diploid Spore Producing Structure:

Meiosis (2n n)

PLASMOGAMY

Dikaryotic Stage

KARYOGAMY

Meiosis

nBasidiospores

Primary mycelium

Secondary mycelium

Sexual Reproduction

n + n 2n

+ mating type- mating type

Rusts & Smuts Affect Plant Crops

Wheat stem rust - Puccinia graminis

Smut fungus on corn

Plylum Ascomycota - “Sac” fungi(largest phylum)

Truffles

Includes Penicillium moldCup fungi

Penicillium mold, an ascomycete

Phylum Ascomycota

Ascus = Diploid Spore Producing Structure:

Meiosis (2n n)

Conidiophore = Haploid Spore Producing

Structure:Mitosis (n n)

n

n + n 2n

+ mating type

- mating type

Asexual Reproduction in Yeasts (unicellular ascomycote)

Budding

YEAST(MOTHER)

CELL

NEW YEAST CELL

Recent additions to Ascomycota…

Athlete’s food & Ringworm

ZygomycotaEx.: black bread mold, Rhizopus stolonifer

(asexual)

Phylum Zygomycota

Zygosporangium = Diploid Spore Producing Structure:

Meiosis (2n n)

Sporangium = Haploid Spore Producing Structure:

Mitosis (n n)

2n

n

+ mating type

- mating type

(informal) Phylum Deuteromycota• “Imperfect Fungi” because only observed to

reproduce asexually

May be moved to other phyla as research continues…

Predatory FungusNematode-Trapping Fungus

Arthrobotrus , a deuteromycete, capturing a round worm

(nematode)

25 C 37 CDimorphic FungiCan exist asmold / hyphal / filamentous form (usually at room temperature) oryeast (body temperature) several potential pathogens:

Histoplasma capsulatumFound in bat and bird feces histoplasmosis; affects mainly lungs, can disseminate through body

Candida albicans oral and genital infections

Benefits

• Medicines, including Penicillin, the first antibiotic, isolated from Penicillium fungus

• Food: edible mushrooms, moldy cheese , fermentation products (wine, beer), leavened bread (aerobic), etc.

• Biotechnology – yeasts used in research, including cloning of genes

Fungal Foods

NOT AN ENDORSEMENT

OF ALCOHOL CONSUMPTION!!!

Yeast, sugar, aerobic respiration CO2 makes bread

rise

Alcoholic fermentation (anaerobic)

Mold on blue cheese