Mycology is the branch of biology concerned with the study of fungi, including their genetic and biochemical properties, their taxonomy and their use to humans as a source for tinder, traditional medicine, food, and entheogens, as well as their dangers, such as toxicity or infection.
2. Fungi
• Identification
– Physical appearance
– Colony characteristics
– Reproductive spores
• Fungi differ from bacteria:
– Like acidic environments (pH 5)
– Resistant to osmotic pressure
– Grow in low moisture
– Require less nitrogen
– Can metabolize complex carbohydrates
3. Morphological groups of Fungi
1. The single-celled fungi are yeasts
2. The multicellular fungi are molds
4. Mycology- The study of Fungi
Fungi - includes molds and yeasts.
Molds - exhibit filamentous type of growth.
Yeasts - exhibit pasty or mucoid form of fungal growth.
• Fungi stain gram positive and require oxygen to survive.
• Fungi are eukaryotic, containing a nucleus bound by a
membrane, an endoplasmic reticulum and mitochondria.
• Fungi are heterotrophic like animals and most bacteria;
requiring organic nutrients as a source of energy.
• Fungi are dependent upon enzyme systems to derive
energy from organic substrates.
5. • THE STUDY OF FUNGI IS CALLED MYCOLOGY
• DISTRIBUTION – 20o – 30o
• ALL ARE CHEMOHETEROTROPHS – ABSORB
NUTRIENTS THROUGH CELL WALL
• PREFER AN ACID pH
• MOST ARE OSMOTOLERANT
• MOST ARE EITHER AEROBES OR FACULTATIVES
• NUTRITIONAL NEEDS ARE MINIMAL
• BASIC STRUCTURE OF THE FUNGI
• TYPICALLY EUCARYOTIC
• UNICELLULAR AND MULTICELLULAR (HYPHA)
6. • Fungi are Eucaryotes which need to take
nutrients from the environment for living.
• They are larger than bacteria.
7. Industrial uses of fungi –
• Mushrooms.
• Natural food supply for wild animals.
• Yeast as food supplement, supplies vitamins.
• Penicillium - ripens cheese, adds flavor
• Fungi used to alter texture, improve flavor of
natural and processed foods.
Role of Fungi
9. Fungal Characteristics
1) Fungi can be food sources or ingredients
and go grow almost anywhere!
2) Scientists are not sure how fungi are RELATED to
other organisms, but all fungi except yeast have
many cells
3) Cell wall made of chitin
4) Heterotrophs – decomposers (MOST are
saprophytes) or parasites
5) Body is made of long filaments of hyphae which
form a mycelium and produce enzymes for digestion
6) Reproduce sexually and asexually
*Asexually by spores
*Sexually by mating of hyphae filaments from two
genetically different fungi
10. Importance of Fungi
• Cultivated mushrooms are an important food
crop; yeast is used in baking industry
• Fungi can cause disease in plants and animals,
e.g., Dutch elm disease, apple scab
• Fungi can cause disease in humans, e.g.,
ringworm and athlete’s foot
• Produce antibiotics, e.g., penicillin
• Decomposers ~ recycle organic matter
11. Yeast
Yeasts are very important economically:
- Yeasts are responsible for fermentation of beer and
bread. (Saccharomyces cerevisiae)
- Ethanol production
- Wastewater treatment:
a mixed culture of yeasts Candida lipolytic Candida
tropicalis and Yarrowia lipolytica grown on
hydrocarbons or gas oil.
12. Budding
Budding: a small bud cell forms on the cell, which
gradually enlarge and separate from the mother cells.
Most of the yeasts reproduce by budding.
15. CANDIDIASIS (Candida albicans)
•There are many species of the genus Candida that
cause disease. The infections caused by all
species of Candida are called candidiasis.
•Candida albicans is an endogenous organism. It
can be found in 40-80% of normal human beings. It
is present in the mouth, gut, and vagina.
•It may be present as a commensal or a pathogenic
organism. Infections with Candida usually occur
when a patient has some alteration in cellular
immunity, normal flora or normal physiology.
17. Molds
Molds are filamentous and have a mycelial structure.
•Mycelium is highly branched system of tubes that
contains mobile cytoplasm with many nuclei.
•Hypha is long, thin filaments on the mycelium.
Size: When grow on solid surface, the filamentous
form is 5-20 µm.
When grow in submerge culture, it can form
aggregates and pellets, 50 µm-1mm.
18. Molds
Size:
When grow on solid surface, the filamentous form is
5-20 µm.
When grow in submerge culture, it can form aggregates and
pellets, 50 µm-1mm.
- Cause nutrient transfer problem in the pellet
19. Mold
• Molds are very important economically:
- mushroom farming is a large industry in many
countries.
Agaricus bisporus
http://en.wikipedia.org/wiki/Agaricus_bisporus
21. Mold
- Food industry
The mixed culture including Penicillium sp. for cheese
production.
Aspergillus niger for citric acid production.
- Antibiotics production.
Penicillium notatum
22. Mold Reproduction
• Either by asexual or sexual means.
• Some molds form sexual spores which provide
resistance against heat, freezing, drying and
some chemical agents.
• Both asexual or sexual spores can germinate
and form new hyphae.