FUNGI
An Overview
Characteristics of Fungi
► Eukaryotic
► Most
are multicellular
► Most are microscopic molds or yeasts
The study fungi is known as MYCOLOGY.
Structure of Fungi
► Filaments
of fungi are
called hyphae.
► The cell walls contain
chitin.
► The MYCELIUM is a
mat of hyphae visible
to the unaided eye (
bread mold)
Septated
Unseptated - coenocytic
Reproduction
► Most
fungi reproduce both sexually and
asexually.
► Asexual reproduction – production of
various types of spores
 Sporangiophores- upright stalk with an enclosed
sac ( bread mold)
 Conidia - upright stalk with no enclosed sac
(penicillin)
 Fragmentation – hyphae dry out and shatter
releasing individual cells that act like spores
(athlete’s foot)
 Budding – small offspring
► Sexual
reproduction
 “plus and minus” mating types
 Hyphae of different mating types fuse and give
rise to a specialized structure that produces
spores ( diploid)
 Most fungi are haploid throughout most of their
life cycle
► When
environmental conditions are
favorable, asexual reproduction occurs
rapidly. When unfavorable conditions stress
the organism, sexual reproduction occurs
and the offspring have an increased
likehood that they will be better suited for
the environment.
Fungi decompose dead plant and
animal matter.
► Called
saprophytes, they act as recyclers of dead
organic matter, obtaining food from this material.
► Hyphal tips release enzymes that eventually
decompose and release organic materials into the
surrounding environment.
► Saprophytic fungi appear on dead trees, logs,
plant litter such as leaves, and even dead insects
and animals. Examples: "Gem-studded Puffball"
(Lycoperdon perlatum) and "Turkey
Tail"(Trametes versicolor).
Fungi and Humans
► Many
people have allergies triggered by
mold.
► Fungal skin infections – skin, nails and hair
 Ringworm, athlete’s foot
► Internal
organs - Histoplasmosis
Fungi in Industry
► Fungi
produce many products used in the
medical field such as penicillin,
cephalosporin antibotics, cortisone
► Fungi are used in genetic engineering –
vaccine for hepatitis B was developed using
the yeast plasmid as the vector.
► Yeast is used to make ethanol.
► Yeast are known for making breads rise.
Fungi in the Food Industry
Mushrooms,
morels and
truffles are
widely consumed
by humans.
Fungi are Plant Pathogens
► Many
fungi attack
grain or fruit.
Fungi form beneficial partnerships
(symbiosis) with other organisms
such as trees and flowering plants:
Algae
hyphae
Lichen – symbiotic
relationship between algae
and fungi