School Science Lessons
Microbiology
Fungi
2012-01-29 SP
Please send comments to: J.Elfick@uq.edu.au
Table of contents
9.0.0 Fungi
9.0.0 Fungi
9.203 Bathroom and kitchen mould
9.214 Cellulose digestion
3.43.03a Class Microsporidia
3.29 Cork taint of wine, "corky" wine (2,4,6-TCA)
9.215 Disinfectants, antiseptics and antibiotics
9.207 Fungi classification, Eukaryota
9.207a Fungal infections of humans
6.5 Fungi, Different fungi (Primary)
9.206.2 Fungi, important genera
9.207b Fungi, Phycomycetes, the algae-like fungi
9.206.2.1 Fungi, Species and possible experiments for schools
16.13.6.0 Fungicides
9.212 Ginger beer plant
9.0.3 Heterokontophyta
6.0 Identification, Culture media for
routine cultivation and identification of fungi
9.204 Identification, Slide culture preparation to
identify fungi
3.43.01 Phylum Ascomycota, ascomycetes, ascus-producing
fungi, sac fungi, e.g. Penicillium
3.43.02 Phylum Basidiomycota, basidiomycetes, basidium-producing
fungi, club fungi, e.g. Agaricus
3.43.03 Phylum Zygomycota, zygomycetes, phaecomycota,
phycomycetes, e.g. Rhizopus
3.43.02a Rusts, Uredinales
3.43.02b Smuts
3.43.02c Stinkhorns, e.g. Phallus
9.206.3 Yeast, Phylum Ascomycota, Saccharomyces
cerevisiae
6.5 Fungi, Different fungi (Singular:
fungus)
See diagram 9.201: Mushroom, Agaricus |
See diagram 9.196: Pin-head mould, Rhizopus
Be able to describe the characteristics of fungi and state their importance
in food chains.
Use mushrooms, toadstools, mouldy bread
Fungi are not plants because they are not green and they never get energy
from the sun. They get their energy when they digest plants and animals and
make them rot. Their method of feeding is more like an animal. Fungi can cause
disease and make dead things rot. They can also make useful substances such
as penicillin and alcohol. Fungi work with smaller bacteria to decompose plants
and animals until they completely rot and return their nutrients to the soil.
Imagine if there were no fungi or bacteria, the world would be covered with
piles of dead things. If you put your hand in a compost heap, it feels hot,
caused by the activity of the fungi and bacteria. Fermenting cocoa also gets
hot for the same reason. Most fungi are poisonous so children should wash
your hands after touching them. Use some examples of fungi to class.
1. If you have ever broken open some rotten wood, what did you see inside?
[White threads and sometimes something growing out of the wood.] This is a
fungus that is eating the wood and making it rotten. Use such an example to
class.
2. Show the children the different fungi they have collected. Do not cook
any fungi for eating because only an expert can tell whether a mushroom is
edible, e.g. field mushroom (Agaricus campestris) and button mushroom
(Agaricus bisporus) or is poisonous.
2.1 Toadstools like little umbrellas growing out of the ground or rotten
wood. They may be poisonous and glow in the dark, e.g. Calvatia,
Filoboletus.
2.2 Bracken fungi are hard and grow out of the trunk of trees, e.g. Pycnosporus.
Some grow on cow dung, e.g. Pilobilus. 3. Some fungi are parasites. They attack
living things, e.g. diseases on the human skin and ear, and diseases of cocoa
and groundnuts (peanuts) may all be caused by fungi. 4. Yeasts are tiny fungi
that cause fermentation. Yeasts change sugar into alcohol. They cause fermentation
of cocoa and are used to make beer.
2.3 Are fungi good or bad? [Fungi that are parasites are bad because they
cause disease, all the other fungi are good.]
2.4 What would happen if there were no fungi to make things rot? [Nutrients
would not return to the soil and the world would be covered with dead things.]
2.5 Study mouldy bread and rotten fruit. Collect waste foods in a sealed
glass container see the life of fungi, e.g. cut boiled potato, cut orange,
bread. The fungi grow like little threads. They push the ends of the threads
into to food to digest it. So they get their food like animals not like plants.
If you keep the glass container sealed, you will see water appearing inside
the glass for the respiration of the fungi. After a few days the fungi form
usually black rounded structures which will burst open to let out tiny spores.
The spores are usually carried in the wind to the next food where they grow
into a new fungus.
2.6 Leave citrus fruit, e.g. two oranges and lemons, in a bowl on the table
for a week. Divide the fruit into two samples and put each sample into a plastic
bag with some wet cotton wool. Tie the mouths of the bags tightly with string
to make them both airtight. Put one plastic bag in box where the fruit will
be warm and in the dark. Put the other plastic bag in a refrigerator. After
two weeks examine the fruit. The citrus fruit in the refrigerator may appear
smaller due to loss of water but the fruit in the box may have a blue-green
fur covering of Penicillium.
9.207 Fungi classification
See 16.3.1.7: Chitin
Fungi have no chlorophyll and the main body, hypha, has walls containing
chitin. Fungi may be unicellular or filamentous so are generally classified
as yeasts, moulds and mushrooms. Asexual spores, conidia, are cut off from
the ends of conidiophore hyphae. A fungus infection of humans is called a
mycosis.
Fungi, Eukaryota, mycota, the "true fungi" are classified into the following 6 groups
1.0 Phylum Ascomycota 3.43.01
includes Saccharomyces cerevisiae, Saccharomyces bayanus
2.0 Phylum Basidiomycota 3.43.02
3.0 Phylum Chytridiomycota 3.43.08
4.0 Phylum Glomeromycota 3.43.09
5.0 Phylum Zygomycota 3.43.03
6.0 Mitosporic fungi 3.43.04
(formerly Deuteromycota or "fungi imperfecti", because no sexual reproduction had been observed)
Not "true fungi"
Stramenopila or Heterokontophyta: 9.0.3
Oomycota, water moulds, include the parasites Phytophthora, | Pythium, | Peronospora
Hyphochytridiomycota
Labrinthulomycota
Not "true fungi"
Slime moulds
Myxomycota: 9.0.17
Plasmodiophoromycota
Dictysteliomycota
Acrasiomycota
9.207a Fungal infections of humans
Fungal infections of humans are rare except from Candida spp. and Aspergillus spp.
Actinomycosis, Aspergillosis, Aspergillus spp. bloodstream infection
Blastomycosis, Candidiasis, Candida spp. lung infection
Chromoblastomycosis
Coccidioidomycosis
Cryptococcosis
Dermatophytosis
Onychomycosis, Histoplasmosis
Mycetoma
Paracoccidioidomycosis
Sporotrichosis
Tinea barbae (ringworm of the scalp)
Tinea capitis (ringworm of the scalp
Tinea corporis (ringworm of the body)
Tinea pedis (ringworm of the foot)
Zygomycosis
9.207b Fungi, Phycomycetes,
the algae-like fungi
In former classification systems, most of the following groups were classified
together as the Phycomycetes, the algae-like fungi.
3.43.04 Deuteromycota (now called the "mitosporic
fungi") deuteromycetes, imperfect fungi, fungi imperfecti, anamorphic fungi
(They are Ascomycota and Basidiomycota in which sexual reproduction is unknown,
so they are called "imperfect".)
9.206.2 Fungi, important genera
Agaricus
Amanita
Aspergillus
Blastomyces
Botrytis
Candida
Claviceps
Colletotrichum
Cryptococcus
Elsinoe
Epidermophyton
Eurotium
Fusarium
Microsphaera
Microsporum
Mucor
Mycosphaerella
Penicillium
Peronospora
Phytophthora
Puccinia
Pythium
Rhizopus
Saccharomyces
Trichophyton
9.206.2.1 Species and possible
experiments for schools
Armillaria mellea, honey fungus, causes decay of timber
Armillaria ostoyae, honey fungus, specimen in Blue Mountains, Eastern
Oregon, 3.4 square miles and said to be the largest living thing.
Candida utilis, producing biomass
Chactomium globosum, grows on paper
Chactomium globosum, digests cellulose
Coprinus lagopus, grows on horse dung
Helminthosporium avenae, oats pathogen
Kluyveromyces lactis, ferments lactose, produces chymosin, rennet
Leptosphaeria maculans, Brassica pathogen
Myrothecium verucaria, digests cellulose
Phaffia rhodozyma, red yeast, used to colour food, e.g. farm salmon
Phycomyces blakesleanus, has phototropic sporangiophores, heterogenesis
Physalospora obtusa, causes apple disease, may produce pectinase
Phytophthora infestans, causes potato blight, has motile zoospores
Plasmodiophora brassicae, causes Brassica club root disease
Pleurotus ostreatus, edible oyster cap mushroom
Rhodutorula rubra, coloured yeast colony
Rhytisma acerinum, lesions on sycamore leaves indicates air pollution
Saprolegnia litoralis, parasite of pond animals
Schizosaccharomyces, large cells that divide by binary fission
Selerotinia fructigena, (Monilinia fructigena) causes apple
brown rot
Sordaria fimicola, used to study meiosis in fungi
Sordaria brevicollis, used to study meiosis in fungi
Sporobolomyces, grows on leaf surfaces, spores forcibly ejected
Trichoderma reesei, used for production of cellulase
Trichoderma viride, decomposing cellulose
9.206.3 Yeast, Phylum Ascomycota,
Saccharomyces cerevisiae
6.6.18 Alcoholic fermentation, yeast, Saccharomyces
cerevisiae
4.3.7 Breakdown of protein by
micro-organisms
3.38 Carbon dioxide and fermentation for
brewing
4.1.2 Enrichment of wild yeast strains
12.7.20 Ferment sugar with yeast
17.4.2 Fermentation using yeast
2.1.1 Fermentation, Safety in school
science
9.212 Ginger beer "plant"
9.158 Heat of respiration, bakers'
yeast (Saccharomyces cerevisiae)
19.1.6.0 Leavening agents (See 3.)
4.3.21 Micro-organisms and personal
hygiene
4.3.8 Prepare alcohol using immobilized
yeast cells
4.2.3 Prepare lactic acid in sourdough
4.2.4 Prepare wine from grape juice
and make vinegar from wine
3.27 Red yeast rice, Monascus purpureus
Saccharomyces
9.206.1 Sampling yeast populations
4.3.22 Sensitivity of micro-organisms
to antiseptics
4.1.8 Streptomycin on Saccharomyces
cerevisiae, using the small disc test (See 10.2)
9.3.12 Tests for
zymase and catalase in yeast
11.3.3 Triple scale wine hydrometer
9.207.1 Wild yeasts in flowers
3.35.4 Yeast cells convert glucose to
carbon dioxide gas and alcohol
19.2.11 Yeast, fermentation, brewing,
whisky, fish sauce
9.205 Yeast population, bakers'
yeast
9.205.1 Saccharomyces cerevisiae, Phylum Ascomycota
9.205.2 Mycoderma, Phylum Ascomycota
3.43.01 Phylum Ascomycota,
ascomycetes, ascus-producing fungi, sac fungi, truffle
Aleuria, orange peel cup fungus
Alternaria alternata, causes early blight of potatoes, ink disease
of kangaroo paws (Australian plant) respiratory diseases in AIDS patients
Alternaria citri, causes brown spot of mandarin
Alternaria dauci, causes leaf blight of carrot
Alternaria infectoria, causes disease of wheat, hay fever and asthma
in humans
Alternaria panax, causes leaf blight of umbrella tree (Schefflera
arboricola)
Alternaria passiflorae, causes brown spot of passionfruit
Amanita, agaric mushroom, fly agaric, poisonous toadstool, muscimol,
muscimole, muscarine
Armillariella mellea, honey-fungus
Aspergillus
See diagram: 9.203: Conidial head
Aspergillus flavus produces a toxic substance, an aflotoxin, and
is a common soil saprophyte, and a pathogen of humans and animals.
Aspergillus nidulans, is NOT suitable for use in schools.
Aspergillus niger, is NOT
suitable for use in schools, causes black mould on onion and food, produces
citric acid, and is a common infection outside the ear drum, and is a common
laboratory contaminant.
Aspergillus oryzae, NOT
suitable for use in schools, produces amylase, and is used to make Japanese
rice wine, sake.
Botrytis spp. neck
rot of onion
Botrytis cinerea causes diseases of strawberry, grey mould of pear,
lettuce, grape, pelargonium, rose, rotting fruits, and is used to produce
dessert wines, “noble rot”.
Botrytis elliptica causes grey mould of lilies.
Botrytis fabae causes bean plant disease.
Botrytis gladiolorum causes botrytis leaf and flower spot of gladiolus.
Botrytis tulipae causes brown spots on leaves and flowers of tulips.
Candida (formerly
Torulopsis)
Candida genus has yeast-like cells, blastoconidia, that reproduce
by budding. All members of the genus occur naturally on humans.
Candida albicans, causes yeast infection of oral mucosa,
oesophagus, commensal on mucous membranes and gastrointestinal tract, pathogenic,
causes thrush (candidosis, candidiasis) usually in the human body, red lesions
in skin infections, nail infections. Candida albicans, forms cream
coloured, smooth surface waxy colonies on an agar plate. It is a commensal
of the gastrointestinal tract. Candidiasis (candidosis) a common yeast infection,
especially of the vagina, where it is called thrush.
Candida glabrata, common yeast species on human body surface, and
can be pathogenic.
Candida tropicalis is part of the normal mucocutaneous flora but
may cause causes septicaemia and candidiasis. It has been isolated from polluted
water, soil, and air contaminated by human excreta.
Candida utilis
Ceratocystis
Cercospora beticola, causes cercospora
leaf spot disease of silver beet
Cercospora violae, causes leaf spot of violet
Claviceps purpurea
(Family Clavicipitaceae) ergine, d-lysergic diethylamide, ergot fungus, ergometrine
causes abortions, ergotamine used for migraine headaches, natural LSD, plant
pathogen of rye seed heads [d-lysergic acid amide, d-lysergic acid diethylamide,
LSD]
See 11.11.9.1: LSD
Colletotrichum
Colletotrichum acutatum, causes black spot of strawberry
Colletotrichum gloeosporioides, causes harmless spots on macadamia
nut, rusty blight on mango leaves, anthracnose disease of tomato fruit
Colletotrichum lindemuthianum, causes anthracnose disease of beans
Colletotrichum orbiculare, causes anthracnose disease of cucurbits,
e.g. cucumber, water melon
Colletotrichum trichellum, causes leaf spot of ivy
Cordyceps sinensis,
caterpillar fungus, "summer grass", folk medicine to stimulate immune system
in China, Tibet, Nepal
Cordyceps subsessilis, source of immunosuppressive, ciclosporin
Cordyceps unilateris, infects ants and changes their behaviour
Didymella bryoniae, causes gummy stem blight of cucurbits, e.g.
watermelon
Diplocarpon mespili, causes fleck disease
of pears and quinces
Diplocarpon rosae, causes black spot disease of roses
Dipodascus
Drechslera turcica, causes leaf blight of sweet corn
Elsinoe
Elsinoe ampelina, causes black spot of grape
Elsinoe rosarum (Splaceloma rosarum), causes anthracnose
disease of roses, raspberry
Elsinoe tristaniae, causes anthracnose disease of raspberry, leaf
spot of brush box
Elsinoe venata, causes cane spot of raspberry
Endothia
Epidermophyton, causes tinea
Erysiphe, powdery mildew
Eurotium
Examine a mycelium of Eurotium under high power. Note the branched,
septate hyphae. Look for conidiophores producing chains of conidia. Observe
perithecia attached to the mycelium by thicker hyphae of a darker colour.
Gently press the coverslip to burst the wall of sterile hyphae so that the
small asci will be extruded. Examine one ascus and look for the eight ascospores.
Fusarium
Fusarium, causes Panama disease of bananas, Fusarium wilt,
basal rot of daffodil
Most Fusarium species are soil fungi. Some are plant pathogens causing
stem rot, root rot and fruit rot.
Fusarium graminearum, infects barley, causes red rust on wheat
Fusarium oxysporum, common plant pathogen causes Panama disease
of bananas, fusarium wilt of carnation, cucurbits, tomato, fusarium bulb
rot of lily, fusarium yellows of gladiolus, fusarium patch of cool climate
grass, and dangerous infections in human burns victims.
Fusarium solani, digests cellulose
The banana root nematode, (burrowing nematode, worm or eel worm), Radopholus
similis, lives in most banana growing regions. The tiny worms make red
brown tunnels in the banana roots and corm. Fusarium oxysporum, infects
the tunnels causing root rot or blackhead disease. The roots rot and weaken
the plant that may topple over in strong wind after the heavy fruit bunches
have formed.
Fusicladium carpophilum,
causes freckle disease on stone fruit, e.g. apricot, peach
Geastrum, earth-stars
Glomerella cingulata,
causes anthracnose disease of avocado, bitter rot of apple, camellia die back
Histoplasma capsulatum,
causes Darling's disease
Leptosphaeria maculans,
causes black leg of crucifers, e.g. cabbage
Marssonina rosae
(Diplocarpon rosae) causes black spot disease of rose
Microsporum
M. audouinii and M. ferrugineum, cause non-inflammatory infections
of the scalp (tinea capitis) especially in children.
M. canis, causes ringworm, especially in children. The infection
comes from cats and dogs.
M. gallinae, causes "white comb" lesions in chickens.
M. nanum, causes chronic non-inflammatory lesions in pigs. Infected
pigs may infect humans.
Microsphaera penicillata, powdery mildew parasite on lilac (Syringa vulgaris)
Mycosphaerella
Mycosphaerella, causes leaf and pod spot of pea, leaf spot of eucalyptus
Mycosphaerella fijiensis, causes black Sigatoka disease of bananas
Mycosphaerella fragariae, causes leaf spot of strawberry
Mycosphaerella musae, causes cordana leaf spot, leaf speckle, tropical
speckle of banana
Mycosphaerella musicola, causes leaf spot of banana
Monilinia
Morchella
Nematospora (Eremothecium)
Neurospora crassa, red bread mould
Penicillium
Penicillin antibiotic, Phylum Ascomycota
Has brush-like conidiophores, (Latin: peniculus, brush)
See diagram 9.202: Penicillium | See diagram 9.202.1: Penicillium with branching conidiophores
| Penicillium, penicillin antibiotic
Penicillium, soil mould
P. purpurogenum (P. rubrum) plant pathogen
P. candida, P. camemberti, P. glaucum, cheese-making, P.
chysogenum (P. notatum) antibiotic penicillin
P. italicum, P. olivaceum, fruit parasites
Penicillium chrysogenum, produces penicillin, yellow pigment
Penicillium expansum, causes apple disease
Penicillium notatum, is NOT suitable for use in schools, produces
penicillin
Penicillium roqueforti, used to make blue-veined cheese
Penicillium wortmanii, produces wortmin a member of the sclerotiorin
group of metabolites
Different species produce antibiotics, and are essential for production
of certain cheeses, e.g. Roquefort and Camembert. Antibiotics are excreted
by micro-organisms to interfere with the growth or metabolism of other micro-organisms.
In the original penicillin, the R-group was a mixture and may be varied by
adding molecules to the nutrient solution in which the mould is growing.
Penicillin interferes with the building up of the cell wall of the cells
of Gram positive bacteria.
Gram-positive bacteria appear blue or violet under a microscope from the
crystal violet dye in Gram stain. Gram-negative bacteria appear pink-red.
However, some bacteria have developed the enzyme penicillinase, that can destroy
penicillin.
Peziza, cup fungus,
saprophytic in wood
Phallus, stink horns
Phoma foveata, (Phoma exigua var. foveata), causes
gangrene of potato
Phomopsis obscurans, causes leaf blight of strawberry
Phomopsis viticola, causes dead-arm disease of grapes
Pneumocystis jirovecci, affects AIDS patients
3.27 Red yeast rice, Monascus
purpureus
It is used to produce red purple fermented rice called "red yeast rice"
with the Chinese brand names "Xuezhikang (XZK)" or "Hypocol". Red yeast rice
is used for food colouring, e.g. Peking duck and pickled tofu. Also, it is
a Chinese herbal medicine. Clinical trials have shown that it may reduce
the chance of repeated heart attacks after surgery better than other statins.
However, it may cause liver damage.
Saccharomycodes
Seiridium, causes cypress canker
Septoria, causes leaf spot of chrysanthemum
Septoria apiicola, causes late blight of celery
Septoria gerberae, causes leaf spot of gerbera
Septoria ribis, causes leaf spot of blackcurrant
Schizosaccharomyces octosporus
Sphaceloma fawcettii, causes citrus scab disease of lemon
Sphaerotheca
Taphrina deformans, causes leaf curl disease of peach, witches'
broom
Trichoderma, a soil mould
Trichophyton
Ringworm disease
Many strains of Trichophyton as medical fungi exist but they are
generally classified as T. rubrum (downy type) and T. rubrum
(granular type). The downy type has slender microconidia and no macroconidia
and causes chronic infection of the skin and nails. The granular type has
microconidia and cigar-shaped macroconidia. It causes tinea corporis in South-East
Asians and in aborigines in Northern Australia and a chronic scarring
form of tinea capitus (favus) a type of ringworm of the scalp, and dhobie
itch (tinea cruris) that affects the groin and nearby regions. Some strains
can invade human hairs and cause the "black dot" form of tinea capitis. Also,
Epidermophyton causes ringworm.
Athletes' foot
Trichophyton mentagrophytes causes tinea pedis, "athletes' foot",
usually between the third and fourth toes of the feet in Europe and
North America,
Tuber, truffle, morel
Venturia
Zygosaccharomyces
3.43.02 Phylum Basidiomycota,
basidiomycetes, basidium-producing fungi, club fungi, sexual spores are produced
on a club-shaped basidium
e.g. Ganoderma lucidum, white rot, ling zhi, herbal remedy
Agarics, gill fungi
Boletes, fleshy pore fungi
Clavarias, coral-like fungi
Gasteronmycetes, puff ball fungi, body ruptures to release spores
Hynoids, spine fungi
Phalloids, stinkhorn fungi
Polypores, bracket fungi
Tholopores, leather shelf fungi
Tremellales, jelly-like fungi
Psilocybe cubensis, psychedelic mushroom, (contains psilocybin and psilocin), (boomers, cubes, gold caps), Family Strophariaceae (previously Stropharia cubensis)
Psilocybe semilanceata, psychedelic mushroom (contains psilocybin
and baeocystin), (liberty cap, magic mushroom), conical cap Family Strophariaceae
3.43.02.1 Edible mushrooms
See diagram 9.201: Agaricus
The following are examples of edible mushrooms but some of them cannot
be distinguished easily from toxic mushrooms, e.g. Morchella sp., so if
not a mushroom expert purchase edible mushroom from a reliable source
Agaricus campestris, field mushroom,
Agaricus bisporus, white mushrooms, Swiss brown mushroom,
Boletus edulis, pennybun, porcino, cep, white mushroom, steinpitz
Cantharellus cibarius, chanterelle, yellow chanterelle
Grifola frondosa, maitake, sheep's head
Lentinula edodes, shiitake mushroom, Chinese black mushroom
Morella conchita, black mushroom
Pleurotus ostreatus, edible oyster cap mushroom
Tuber aestivum, summer truffle
Examine the reproductive portion of a mushroom. Choose a ripe fructification
and remove the stipe and place the umbrella-shaped part, the pileus, on a
piece of paper with the gills downwards. Leave for a few days, then gently
lift the pileus. See the arrangement of the gills traced on the paper by thousands
of small, black, reproductive spores that have been shed. Study a prepared
slide of the longitudinal section of a gill to observe its detailed structure
and the means of basidiospore production.
Amanita muscaria,
fly agaric, white flecked cap turns orange when dry, poisonous, hallucogenic
(contains muscimol), herbal remedy if boiled, Amanitaceae
Armillaria, armillaria root rot of strawberries and woody ornamentals
Calvatia, giant puffball mushroom
Clavaria
Coprinus, on dung pads
Crucibulum laeve, bird's nest fungus
Cryptococcus
C. gattii, causes mass lesions in the lung and brain.
C. neoformans, causes fungal meningitis.
3.43.02a Rusts, Uredinales
Puccinia, wheat rust
Puccinia triticina, wheat stem rust
Puccinia graminis, soybean rust
Puccinia chrysanthemum, of chrysanthemums
Puccinia iridis, of iris
Puccinia lagenophorae, of English marigold
Phakopsora, white pine blister rust, apple cedar rust, hollyhock
rust, asparagus rust, white pine blister rust
3.43.02b Smuts
Maize smut (corn smut), Ustilago maydis, sugar cane smut Ustilago
scitaminea, loose smut Ustilago nuda
Karnal bunt, partial bunt, caused by Tilletia indica
3.43.02c Stinkhorns, e.g. Phallus
Family Phallaceae
Aseröe rubra
Clathrus
Colus
Dictyophora
Laterna
Leucocoprinus birnbaumii
Lysurus mokusin
Mutinus
Phallus impudicus (looks like yellow morel)
Pilobolus
Polyporus stolonifera, bread mould
Rhizoctonia leguminicola, red patch disease of red clover, brown patch
of lawn grass, "damping-off" disease of seedlings
Rhizoctonia solani, collar rot of beans
3.43.03 Phylum Zygomycota,
zygomycetes, phaecomycota, phycomycetes, have no cross-walls (septa)
Encephalitozoon cuniculi, causes diarrhoea in AIDS patients
Mucor, cheese-making
See diagram 9.202
Place some damp bread under a large jar, and leave it for a few days until
it becomes mouldy. Take a small portion of the mouldy bread and examine the
fungus responsible with the high power. Look for spore-producing bodies of
Mucor. Study prepared slides showing stages in sexual reproduction. Examine
a culture of the two strains (+ and -).
Mucor species are NOT suitable
for use in schools
Mucor genevensis is used to study sexual reproduction.
Mucor hiemalis is used to study sexual reproduction.
Mucor mucedo is the black “pin mould” on bread.
Mucor pusillus (Rhizomucor pusillus) is unsuitable for use
in schools.
Rhizopus
Rhizopus nigricans, mouldy bread, Phylum Zygomycota
See diagram 9.196: Rhizopus nigricans, bread mould | See diagram
9.196.1: Rhizopus oryzae
Rhizopus genera have stolons, pigmented rhizoids, with sporangiophores
from nodes above the rhizoids, dense white to brown cotton-like growth
Rhizopus nigricans, bread mould, stolonifer black bread mould
Rhizopus oryzae (R. arrhizuz) fermentation of foods, Japanese
sake
Rhizopus oligosporus, ferments soya beans to make “tempe”
Rhizopus sexualis is used to study linear growth
Rhizopus stolonifer produces lipase
1. Mount a small fragment of mould from old bread or decaying fruit and
examine under the low power. Note the filaments that are the vegetative body
of this fungus.
2. Invert a smaller flat transparent dish in the bottom of a larger flat
transparent dish. Stand a piece of bread on the small dish. Add tap water
to the large dish until it is half way up the side of the small dish. Cover
the larger dish with its lid and leave the assembly to stand at room temperature.
Under these moist chamber conditions, off-white, furry masses of mould (Mucoraceen
and Aspergillacae) develop after a few days on the bread. Later these form
grey-black or green sporophores.
3. Label 4 plastic bags with zippers as bag 1, bag 2, bag 3, and bag 4.
Place a slice of dry white bread in bag 1 and seal. Sprinkle 20 drops of
water on a slice of white bread to just make it damp, place it in bag 2 and
seal. Sprinkle 20 drops of lemon juice on a slice of white bread, place it
in bag 3 and seal. Rinse the eye dropper with water, then sprinkle 20 drops
of sugar water on a slice of white bread, place it in the bag 4 and seal.
Check the bags daily for two weeks and record your observations. Use graph
paper to measure how much the mould spreads and calculate the percentage
of the bread covered by the mould. Wash your hands each time after working
on the experiment and be very careful not to inhale the mould spores. Note
what bread mould needs to grow. Note whether all bread mould is identical.
Leave the sealed plastic bag for a long time and note what happens. Repeat
the experiment at different temperature, in the light and dark, with different
types of bread (some containing preservatives), with different amounts of
liquid, with old and fresh bread, with bread and toast.
Uromyces betae silver
beet rust
Uromycladium, acacia gall rust fungus
3.43.03a Class Microsporidia
Tiny parasites with no mitochondria
Loma in fish, Abelspora in crab, Amblyspora in
mosquito
3.43.04 Deuteromycota (now
called the "mitosporic fungi") deuteromycetes, imperfect fungi, fungi imperfecti,
anamorphic fungi (They are Ascomycota and Basidiomycota in which sexual reproduction
is unknown.)
Arthrobotrys
Blastomyces
Blastomyces dermatitidis pathogen causes blastomycosis, pustules
form on the skin, cultures are a biohazard to laboratory personnel!
3.43.05 Myxomycota, Mycetozoa,
Myxomycetes slime fungi, fungus animals, fungus-like slime moulds, many micro-organisms
but most not fungi, also giant kelps
1.0.1 Kingdom Protista, Heterotrophic protists
Fuligo, yellow slime mould, Protista, Mycetozoa
Sternonitis, Protista, Mycetozoa
Physarum, many headed slime, "pet slime
mould", Protista, Mycetozoa
3.43.06 Oomycota, oomycetes,
water mould, egg fungi, but it is not a fungus. It is similar to brown algae.
The zoospores have two cilia. (They are nowadays usually classified under
the Heterokontophyta division of the Algae, or put in the Kingdom Chromista.)
7.01 Kingdom Chromista
9.0.3 Phylum Heterokontophyta
Albugo candida,
(Cystopus ), water mould, white rust
Bremia lactucae, downy mildew of lettuce
Monoblepharis
Peronospora
Peronospora destructor, downy mildew of onion
Peronospora jaapiana, downy mildew of rhubarb
Peronospora parasitica, downy mildew of stocks
Peronospora sparsa, downy mildew of rose
Peronospora viciae, downy mildew of pea
Phytophthora
Phytophthora infestans, potato blight (late blight of potato)
Phylum Heterokontophyta
Potato blight, die back, root rot, cocoa black pod
This fungus caused the potato famine in Ireland 1845. Examine the leaf
of a potato plant infected with potato blight. Look for the lighter patches,
or if the disease is advanced they will appear dark brown, where the leaf
is attacked by the fungus. Obtain a prepared microscope slide of a section
of an infected leaf and observe dark blotches on leaf tips and white mould
under the leaves. Study prepared slides showing the method of reproduction.
Phytophthora, brown rot disease of citrus, especially "Washington
Navel" orange and lemons, top and root rot of pineapple
Phytophthora citrophthora, collar rot of citrus
Phytophthora nicotianae, phytophthora blight of passion fruit
Pythium
Pythium, root rot, damping-off fungus, Phylum Oomycota
Pythium blight, cottony blight is a fungal disease of grass, especially
turf grass, "damping off" of lawns, dollar spot, greenhouse seedlings and
black stem rot of Pelargonium. It causes small patches of blighted
grass with shrivelled leaves during warm, wet periods.
Pythium ultimum, black pseudo-bulb rot of cymbidium orchids
Pythium de baryanum, causes seedling “'damping off”, e.g. cress
Observe Pythium under the low and high powers. Study prepared slides
of the asexual and sexual methods of reproduction.
Plasmopara viticola, downy mildew of grape
Saprolegnia, water mould, cotton mould
3.43.07 Hyphochtridiomycota,
hyphochytridiomycetes, zoospores with just one anterior flagellum
(They are nowadays usually classified under the Heterokontophyta division
of the Algae, or put in the Kingdom Chromista.)
9.0.2 Chromista
9.0.3 Heterokontophyta
Aimillaria, Lactarius,
Tremella
3.43.08 Phylum Chytridiomycota,
Chytridiomycetes, chytrids, Algae: Heterokontophyta zoosporic fungi, aquatic
fungi, asexual, single cilium, saprophytic
9.0.3 Heterokontophyta
Allomyces
Batrachochytrium, kills frogs
Chytriomyces
Monoblepharis
Rhizophydium
Synchytrium endobioticum, potato wart disease, black scab
3.43.09 Phylum Glomeromycota,
Glomerales, mycorrhizal associations, arbuscular (lives inside plant cells)
mutualistic
Acaulospora
Geosiphon
Glomus
Nostoc
Pacispora
Paraglomus
Physoderma
Siphonaria
3.29 Cork taint of wine, "corky"
wine (2,4,6-TCA)
See 16.1.3.2: 3. Phenols (group: OH-C
in a benzene ring) (phenol = C6H5O6)
The "damp cardboard" taste of corky wine is caused usually by 2,4,6-trichloroanisole
(2,4,6-TCA) mould produced mainly by Trichoderma and Fusarium
strains of fungi when in contact with chlorine used to bleach corks made from
the bark of the cork tree, Quercus suber.
The waiters in high class restaurants will smell the cork before first pouring
the newly-opened wine to detect any unpleasant odours. The taint taste of
2,4,6-TCA may also cause the "Rio" defect in South American coffee and affect
beer, sake and fish and prawns. Nowadays, the wine cork is being replaced
by screw-top caps, e.g. the Stelvin capsule, "Stelvin Lux", that seals the
bottle but allows a very small amount of air to touch the surface of the
wine to allow maturation. Although the screw-top capsule prevents "corkiness",
the taste of the wine may still be affected by excess exposure to the air
if it is loose. Excessive oxidation of wine may cause unpleasant odour and
bad tastes so corked wines are usually stored horizontally to keep the cork
moist and prevent shrinkage. However, fortified wines, e.g. sherry and port,
have brandy added before fermentation is complete, leaving some residual
sugar in the wine because the remaining yeast is killed by the extra alcohol
from the added brandy. The alcohol content may rise from 10 -13% in wine
to 16-20% in port. However, Madeira fortified wine is said to taste better
if it is slightly oxidized so it it traditionally stored upright to avoid
any corky taste yet allow some oxidation.
9.212 Ginger beer "plant"
Ginger beer "plant" is the yeast Saccharomyces florentinus, (S.
pyriformis), and the bacterium Lactobacillus hilgardii (Brevibacterium
vermiforme).
Add 5g of bakers' yeast to 25 ml of water and 1/2 teaspoon of ground ginger
and sugar. Put in a screw-top jar and add half a teaspoon of sugar and some
ground ginger every day for a week to keep the fermentation going. Dissolve
50g of sugar in 50 ml of boiling water. Strain the mixture and add the sugar
solution and lemon juice to the liquid. Ginger beer soft drink is made from
ginger powder and does not contain alcohol. Some people use baker's yeast
ot dried yeast to make ginger beer. If too much sugar is used in the ginger
beer mixture the extra carbon dioxide produced make cause dangerous explosions
of glass bottles.
9.203 Bathroom and kitchen
mould
Moulds may grow in the "grout" between bathroom and kitchen tiles. In Australia
these moulds are usually Penicillium, Rhizopus, Phoma, Phialophora, and Fusarium.
They are mostly harmless although Phoma may cause allergies. They can be cleaned
off with bleach solutions.
9.204 Slide culture preparation
to identify fungi
See diagram 9.208: Simple agar block method
1. To identify many fungi you must observe the conidiophores, i.e. the
specialized hyphae where asexual spores cut off at the ends, and the way
in which spores are produced. This method allows you to study fungi with
little disturbance. Use one agar plate of nutrient agar, e.g. potato dextrose
agar.
2. Use a sterile blade to cut out an agar block, 7 x 7 mm, small enough
to fit under a coverslip.
3. Flip the agar block up onto the surface of the agar plate. Inoculate
the four sides of the agar block with spores or mycelia fragments of the
fungus to be grown.
4. Place a flamed coverslip centrally upon the agar block. Incubate the
plate at 26oC until growth and spore-forming have occurred. Remove
the coverslip from the agar block.
5. Apply a drop of 95% alcohol as a wetting agent. Gently lower the coverslip
onto a small drop of lactophenol cotton blue on a clean glass slide. Leave
the slide overnight to dry and later seal the edges with a coat of clear fingernail
polish followed by one coat of red coloured polish.
9.205 Yeast population, bakers'
yeast Saccharomyces cerevisiae, Phylum Ascomycota
See diagram 9.204: Yeast cell forming bud
The simplest form of asexual reproduction is budding, in which a protuberance
grows out from the parent cell and finally cutting itself off to become an
independent cell. Budding occurs in yeasts. Natural sources of yeast include
the wax-like coatings on smooth skinned fruits, especially grapes. However,
bakers' yeast is usually obtainable. It reproduces rapidly, making it a good
subject for observing population changes under varying conditions.
1. Set up tubes of sugar, molasses or honey solutions and a water control.
Put a quarter cake of crumbled yeast in each tube. Compare the results. Put
a one-hole stopper with glass tubing in the sugar and yeast solution. Allow
the gas produced to bubble through a tube of clear limewater to detect the
presence of carbon dioxide. Test the gas produced by the sugar and yeast solution.
2. Fill a test-tube half full of 10% sugar solution, drop in a piece of
bakers' yeast, plug the test-tube with cotton wool and leave to stand at
room temperature. After 12 to 24 hours, transfer a drop from this culture
on to a microscope slide using a glass rod, put a coverslip over it and examine
the preparation under a microscope. Look for cells with protrusions or asexual
buds. If you can see nuclei in the cells, look for their presence in the
buds.
9.205.1 Saccharomyces
Saccharomyces: (Bakers' yeast, Saccharomyces
cerevisiae, (beer yeast that tolerate high ethanol concentration S.
ellipsoideus), (wine yeast, S. ludwigii, S. minor), (bread
yeast, S. octosporus), (grape yeast S. pastorianus), (grows
on starch and produces glucoamylase S. diastaticus).
>
9.205.2 Mycoderma
Mycoderma aceti (Ascomycota) produces acetic acid, vinegar) from fermenting wine or malt infusion.
9.206.1 Sampling yeast populations
See diagram 9.204: Yeast cell forming bud
1. Natural sources of yeast include the wax-like coatings on smooth-skinned
fruits, especially grapes. However, bakers' yeast is usually obtainable. It
reproduces rapidly, making it a good subject for observing population changes
under varying conditions.
Set up tubes of sugar, molasses or honey solutions and a water control.
Place a quarter cake of crumbled yeast in each tube. Compare the results.
Place a one-hole stopper with glass tubing in the sugar and yeast solution
and allow the gas produced to bubble through a tube of clear limewater to
detect the presence of carbon dioxide. Yeasts reproduce asexually through
a process called "budding". Place a drop of the sugar and yeast solution
on a microscope slide and cover with a coverslip. Examine the slide with
the high power objective. Look for cells with protrusions or buds. If you
can see nuclei in the cells, look for their presence in the buds
2. Start a culture each day for 10 days using one grain of yeast for each
culture. On the tenth day sample and count all cultures with a microscope.
Use a special slide for counting blood cells, but it is not essential. If
the population on a given day is too large to count, dilute a sample by adding
1 mL of the sample and 9 mL of water. Multiply the count by 10 to get the
actual sample size. If one dilution is not enough, further dilution may be
done until it becomes easy to count the number of organisms. The multiplication
factor for two dilutions is 10 by 10 or 100: for three dilutions it is 10
by 10 by 10 or 1, 000. Note that each successive dilution is started from
part of the previous dilution, not from the original sample. Graph the data
obtained from cultures for analysis. Time is the independent variable and
population size is the dependent variable.
3. An effective method of studying population growth with micro-organisms
is to start a culture each day and, on the final day, to sample and count
all cultures. For example, a new yeast culture can be started each day for
10 days, using one grain of yeast for each culture. On the tenth day samples
are taken from each culture and counted with a microscope. A special slide
for counting blood cells is desirable, but not essential. If the population
on a given day is too large to count, dilute a sample by adding 9 parts water
to 1 part of sample. Use 1 ml of sample and 9 ml of water. Multiply by 10
to get the actual sample size. If one dilution is not enough, make further
dilutions until it becomes easy to count the number of organisms. The multiplication
factor for two dilutions is 10 by 10 or 100: for three dilutions it is 10
by 10 by 10 or 1, 000. Note that each successive dilution is started from
part of the previous dilution, not from the original sample. Graph the data
obtained from cultures for analysis with time as the independent variable
and population size is the dependent variable.
4. Put about half a cup (about 100 mL) of warm water into a glass. Dissolve
1 teaspoon of sugar of the water. Then add 1 teaspoon of the dried yeast and
mix it in well. Write down what it looks and smells like. Put the glass somewhere
warm but not hot, e.g. the top of the hot water system, or wrap a towel around
the glass and put it in an insulated box. Check the glass after 5 minutes
and make the observations again. Note if it changed in looks or smell? Check
it again after another 5 minutes, 10 minutes.
9.207.1 Wild yeasts in flowers
See 4.1.2: Enrichment of wild yeast
strains
Put a few freshly picked flowers of dead nettle, wound wort or nasturtium,
in a beaker. Cover over with a suitably sized transparent plastic bag and
leave the flowers to stand in this "humidity chamber" at room temperature.
After two days remove some flowers that are already open. Pull off the petals
and squeeze the nectar from the nectaries onto a microscope slide. Put a coverslip
over the nectar and examine it under a microscope. Look for nectar yeast
cells. Note the shape of the nectar yeast cells and the size of the buds.
Compare the nectar yeast cells with the bakers' yeast cells. Observe the
cross form or star form of the branching chains formed by the wild yeasts
on budding. Use agar syrup to culture the yeasts and moulds.
9.214 Cellulose digestion
Cellulose is a fibrous substance that helps to provide plants with a rigid
structure. It is the most important plant polymer, making up some 40-50% of
the mature plant cell wall. It is also the most abundant carbohydrate. The
molecules are very large and long and contain carbon, hydrogen and oxygen.
Cellulose is a very stable substance at ordinary temperatures, and the types
of micro-organism that can decompose and thus recycle it are extremely important
in sustaining the turnover of organic matter for the rest of the living world.
It often occurs in a complex mixture with lignin, another plant polymer, called
lignocellulose, in wood, forest and agricultural wastes, and in waste paper.
Cellulose is not soluble in water, so micro-organisms cannot absorb it into
their cells but they secrete the enzyme cellulase which partly digests the
cellulose to breaks it down into soluble sugar molecules which the microbes
can absorb and use. Higher organisms do not make cellulase, so herbivores
cannot digest cellulose themselves. They depend on cellulolytic bacteria in
their intestinal tracts to digest the cellulose for their use. On land the
major decomposers of cellulose are fungi, aided by a few aerobic and anaerobic
bacteria. In marine habitats bacteria are primarily responsible for breaking
down cellulose, but in fresh water aquatic fungi carry out this function in
well aerated zones, with bacteria playing an increasingly important role as
the amount of oxygen diminishes. Cellulolytic bacteria include species of
Cellulomonas, Pseudomonas and Ruminococcus. Cellulolytic
fungi include Chaetomium, Fusarium, Myrothecium and Trichoderma.
9.215 Disinfectants, antiseptics
and antibiotics
Antimicrobial substances include disinfectants, antiseptics and antibiotics.
Disinfection is a procedure that destroys or inactivates micro-organisms.
It usually involves the treatment of non-living objects such as surfaces or
liquids with chemicals (disinfectants) e.g. chlorine, phenols and hypochlorites.
Antisepsis is the disinfection of living tissues with chemicals (antiseptics)
e.g. hydrogen peroxide, iodine and diluted alcohol. Antibiotics are chemicals
that, inhibit or kill certain micro-organisms even at very low concentrations,
Penicillins are a well-known group of antibiotics.
Disinfectants and antiseptics that kill bacteria are said to be bactericidal.
Others merely halt the growth of bacteria and if inactivated, e.g. by dilution,
bacterial growth may be resumed. These substances are said to be bacteriostatic.
So a bactericidal disinfectant or antiseptic may become bacteriostatic when
diluted. Antibiotics are produced by microbes as a natural defence against
other microbes. Some are still produced commercially using microorganisms,
although a large number are manufactured chemically. Some antibiotics are
active against a narrow range of species whilst others affect a broad spectrum
of organisms. The ability to make antimicrobial substances is not limited
to microbes; most animals have antibacterial substances in their bodily secretions,
such as lysosyme in sweat and tears. Plant materials such as garlic (Allium
sativum), tea tree oil (Melaleuca alternifolia) and oil of cloves
(Syzygium aromaticum) also have antimicrobial properties.
Miscellaneous fungi
Cladosporium, brown food mould, soil mould
Cladosporium iridis, leaf spot of iris
Dactylella
Verticillium
Cyathus
Diptoporus betulinus, "razor strap", bracket fungus on birch trees
Exidea glandulosa, "witches' butter"
Exobasidium
Ganoderma, bracket fungi
Geastrum
Lycoperdon, puff ball
Phlebopus boletes
Pleurotus ostreatus, oyster mushroom
Polyporus
Meripilus gigantaeus, bracket fungus
Merulius, dry rot of timber
Phallus, stink horn
Schizophyllum commune, split gill fungus
Venturia inaequalis, causes apple scab mainly of "Granny Smith"
and "Delicious" apples