Eukaryotes

the study of fungi

• yeast
• molds
• mushrooms

–Nature’s decomposers

–A few are pathogenic

Based on sexual spores

–Metabolize complex carbohydrates

–Prefer slightly acidic conditions

• –More resistant to osmotic pressure than
• bacteria

–Yeast – mostly facultative anaerobes

–Molds – mostly aerobes

Unicellular

Divide by budding

Identification based on biochemical tests

–Pseudohyphae: false hyphae, results from a bud that fails to detach

–Candida albicans forms a pseudohyphae

are filamentous fungi

hyphae that possess a septa to divide cells

hyphae that does not possess a septa to divide cells; one cell wall

an organism made up of a multinucleate, continuous mass of protoplasm enclosed by one cell wall

a long, branching filamentous structure of a fungus

hyphae are the main mode of vegetative growth, and are collectively called a mycelium

A typical fungus consists of a mass of branched, tubular filaments enclosed by a rigid cell wall. The filaments, called hyphae (singular hypha), branch repeatedly into a complicated, radially expanding network called the mycelium

Some hyphae grow above a surface and look like branches of a plant.

Some hyphae grow into the surface to absorb nutrients, much like the roots of plants do to gain their nutrients.

mass of hyphae

common environmental mold

have 2 morphologies

Slow growing fungi that grow as molds at 25° and yeast at 37°.

temperature dependent

soil as a mold, producing spores that are often inhaled or introduced into the skin

Grow in the body as a yeast

•Are reproductive

•Not as resistant to environmental conditions as bacterial endospores are

•Molds may make both sexual & asexual spores

–result from the fusion of 2 nuclei from 1 (+) and 1 (-) mating strain of the same species

•important for classification

–make clones of the parent

•Conididospore vs. sporangiospore

a special stalk or branch of the mycelium, bearing conidia

A specialized fungal hypha that produces conidia

a spore that develops in a sporangium

sporangium - an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular

rhizopus (black bread mold)

fungul infection deep within body

•Ex.histoplasmosis & coccidioidomycosis

fungal infection beneath skin

•Ex. sporotrichosis

infects epidermis, hair and nails

•Caused by dermatophytes, make keratinase. Can be passed from person to person

•Fungi grow along hair shafts and surface epidermal cells, common in tropical climates

pathogen that causes disease in immuno-compromised people

•Ex. Pneumocystis in AIDS patients

•Algae + fungi living in a mutualistic relationship

•Slow growing

•Produce organic acids to leech nutrients needed for growth from rocks

• performs photosynthesis and produces
• carbohydrates which it shares with the fungi

• attaches both organisms to a rock, tree,
• etc. and provides protection from desiccation

•Mostly aquatic, living in the top few meters of water

•Simple eukaryotic photoautotrophs

•Fix CO2into organic carbon, and release O2

•Reproduce sexually & asexually

•Classified by rRNA, pigments, & structures

•A few cause disease via toxins made by the algae