FUNGI

Yeasts and Penicillium

FUNGI

Fungi are classified as a separate kingdom

The typical fungus is not made of cells but of tiny branching threads called hyphae

Yeasts are not typical fungi!

FUNGI

The mass of hyphae that makes up one individual fungus is called its mycelium

The hyphae are bounded by a plasma membrane and have a cell wall.

In higher fungi the main component of the cell wall is chitin

FUNGI

Fungi are eukaryotic organisms (unlike bacteria)

They never contain chloroplasts

All are heterotrophic; most a saprophytic; a few are parasitic

FUNGI

Saprophytic fungi are of enormous ecological importance.

Unlike most bacteria they can produce cellulases and lignases

They can also taste exceptionally good!

FUNGI

Penicillium and yeasts are classed as higher fungi

This means that the hyphae are septate (in Penicillium – yeast don’t have hyphae having a cellular structure)

FUNGI

Penicillium is a fungus with many useful enzymes at its disposal to attack a host of organic foodstuffs.   .  

It is partial to bread, cheese, cold meats, old sandwiches, cereal products and a host of other things. 

FUNGI

Penicillium roquefortii  used in the manufacture of blue cheese. 

The blue in the blue-cheese is caused by the pigment in the spores (conidia) of the fungus.  You are consuming spores by the million when you eat blue cheese.   Hope it doesn't put you off! 

Penicillium notatum and P. chrysogenum are used in the production of the antibiotic penicillin. 

FUNGI

Penicillium has feeding hyphae, which divide into branches through its substrate.

It also has aeriel hyphae called condiophores which branch to form sterigma.

FUNGI

Cytoplasm oozes from the tips of the sterigma

This hardens to form chains of green-grey condiospores.

These are dispersed by air currents and can each germinate to form a hypha on a suitable medium.

Penicillium notatum

FUNGI

YEASTSaccharomyces cerevisiae – used in

bread makingSaccharomyces ellipsoideus – used in

wine makingSaccharomyces carlsbergensis – used in

lager makingDiffer form each other by only one gene

FUNGI

YEASTEllipsoid in shapePermeable cell wall

composed of mannose and glucose polymers

Full range of eukaryotic organelles

FUNGI

YEASTOne or more large

vacuoles occupy a central position in the cell

Storage materials such as glycogen and oil globules are often present in the cytoplasm

FUNGI

Yeast Under conditions

unfavourable for growth the yeast can undergo meiosis and produce haploid spores that act like gametes

They usually reproduce asexually by budding