School Science Lessons
2024-07-10
Please send comments to: j.elfick@uq.edu.au
(UNBiology8)
Fungi, Antibiotics, Yeasts
Contents
9.1.0 Fungi
4.9.1 Fungi diseases of plants
9.2.0 Antibiotics
9.3.0 Antifungal drugs
9.4.0 Mushrooms
9.5.0 Not "true fungi
9.6.0 Penicillium
9.7.0 Yeasts
9.1.0 Fungi
Fungi (websites)
4.9.1 Fungi diseases of plants
Aflotoxins
See website: Anthracnose
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 classification
Fungi classification, Eukaryota, mycota, the "true fungi", are classified into the following 6 groups:
9.1.1 Fungi Kingdom
9.1.1 Phylum Ascomycota, (sac fungi)
9.1.2 Phylum Basidiomycota (club fungi)
9.1.3 Phylum Chytridiomycota, Class Chytridiomycetes, Chytrids, zoosporic fungi, aquatic fungi, from Rhynie chert
9.1.4 Phylum Glomeromycota, Glomeromycetes, mycorrhizal associations, arbuscular (lives inside plant cells of roots), mutualistic
9.1.5 Phylum Zygomycota (now in Mucoromycota and Zoopagomycota) (zygote-forming fungi), (conjugated fungi). cheese, bread, Mucor, Rhizopus, Albugo
9.1.6 Mitosporic fungi (fungi imperfecti)
Fungi topics
9.1.8 Aspergillus genus
9.1.9 Bathroom and kitchen mould
9.1.10 Cellulose digestion
16.3.6.9 Clove oil, eugenol
9.1.11 Cork taint of wine, "corky" wine
9.1.12 Disinfectants, antiseptics and antibiotics
4.9.1 Fungi diseases of plants
9.9.0 Fungi, Field fungi
9.1.22 Fungi, important genera
9.1.13 Fungi infections of humans
9.8.0 Fungi species and possible experiments for schools
4.3 Fungicides (Agriculture)
9.0.2 Heterokontophyta
9.7.8 Mycorrhizal plants
4.3.1 SCOBY, Symbiotic Colony Of Bacteria and Yeast
Experiments
9.7.2 Ginger beer "plant"
9.4.0 Mushrooms
6.0 Prepare culture media to identify fungi
9.2.32 Prepare DRBC (food spoilage solution)
9.1.22 Fungi, important genera
Amanita
Armillaria
Agaricus bisporus common mushroom
Agaricus campestris, Agaricus xanthodermus# field mushroom
Aspergillus
Aseroë rubra# a “stinkhorn”, colourful star-like shapes, spore-bearing brown slime has “rotting meat” smell, toxic, grow in Australian mulch
Auricularia cornea#, hairy wood ear, widespread ear-like rubbery fungus on dead wood. grey-brown colour, smooth with hairy greyish cap, tastles but in Chinese cuisine
Cep mushroom, (Boletus edulis), pennybun.
Blastomyces
Botrytis
Candida
Cantharellus cibarius, chanterelle, yellow chanterelle, girole red spots on damaged cap, faint apricots smell, occurs worldwide, commonly consumed and favoured.
Cladosporium, brown food mould, soil mould
Cladosporium fulvum , tomato leaf mould, conidia onto leaves, white mould patches that turn brown, clogged stomates, curlesd leaves wilting, commercial importance
Claviceps
Colletotrichum
Cryptococcus
Chlorophyllum molybdites# geen-spored parasol, vomiter, tall,white fungi with brown centre, appears on grass after rainsharp smell, toxic, many poisonings
Colus pusillus# red basket-like fungus, rotting meat a stinkhorn , grows in mulch a saprotrophic fungus.
Cyathus striatus, a “bird’s nest” fungus , vase-shaped up to 10 mm diameter, grey interior contains 2 mm diameter egg-like groups of spores to be spread by rain drops
Dactylella species form a noose to trap nematodes then use filament to absorb their nutrients, a beneficial biocontrol of agricultural plant pests< br>
Dictyopanus pusillus# “little ping pong bats”, 12 mm height and diameter, pores in surface, stems attached to trees trumks
.
Elsinoe
Eurotium
Exidea glandulosa, "witches' butter", individuals up to 2 cm diameter join to form black gelationous spread across branches leaving a black crust on the wood
Fusarium
Lingzhi mushroom, (Ganoderma lucidum)>
Maitake mushroom, (Grifola frondosa), dancing mushroom
Shiitake mushroom, (Lentinula edodes), Chinese black mushroom,
Microsphaera
Mycosphaerella
Microsporum
Mucor
Mycena viscidocruenta#
9.6.0 Penicillium
9.6.0 Penicillium
9.6.7 Penicillium on rotten fruit and lemon
9.1.18 Stink horns, e.g. Phallus
Pseudocolus fusiformis, Stinky squid, a stinkhorn mushroom in the Phallaceae
Psilocybe cubensis (Stropharia cubensis),boomers", "cubes", "gold caps".
Psilocybe semilanceata, "magic mushroom", "conical cap".
9.1.14 Rhizoctonia
9.1.1.5 Rhizopus, bread mould
9.1.14 Rhizoctonia
9.6.6 Rhizopus nigricans, bread mould
9.1.16 Rusts, Puccinnia species
Schizophyllum commune, grey-white fan-like fungus, attached to moist dead wood, gills split lengthways “split-gill”, 40 cm white-grey fruit body.
Do not smell this pathogenic fungus!
9.1.17 Smuts, maize smut, corn smut
9.1.19 Truffles
Trichophyton
Verticillium dahliae causes verticillium wilt of cotton, enters roots then vascular system, then defoliation and shedding of cotton bolls,
non-host rotation crops needed to deal with this smut.
Venturia inaequalis, "black spot", causes apple scab mainly of "Granny Smith" and "Delicious" apples, more severe in temperate countries with cool, moist climates during early spring
9.2.0 Antibiotics
9.2.1 Antibiotics by name
9.2.2 Antibiotic consumption
9.2.3 Antibiotic resistance in the world
9.2.4 Chloramphenicol, C11H12Cl2N2O5
9.3.0 Antifungal drugs
* Azoles, damage fungal cell membranes
Imidazoles, used to treat Candida
e.g. Ketoconazole C26H28Cl2N4O4, Clotrimazole, Miconazole
Triazoles, used to treat Candida infections, aspergillosis, Fusarium
e.g. Fluconazole C13H12F2N6O, Itraconazole, Posaconazole, Voriconazole, Isavuconazole
* Polyenes, damage fungal cell walls used to treat Candida aspergillosis, blastomycosis, cryptococcosis
e.g. Amphotericin B C47H73NO17, Nystatin
* Allylamines damage fungal cell membranes used to treat skin infections
e.g. Terbinafine C21H25N
* Echinocandins damage fungal cell walls, used to treat Candida infections, aspergillosis
Anidulafungin C58H73N7O17, Caspofungin, Micafungin
* Flucytosine C4H4FN3O attacks fungal nucleic acids and proteins, used to treat Candida or Cryptococcus species.
* Griseofulvin C17H17ClO6, prevents fungal cell division, used to treat skin infections, ringworm
9.4.0 Mushrooms
Edible mushrooms
The following are edible mushrooms, but some cannot be distinguished easily from toxic mushrooms
You are advised so purchase edible mushroom from a reliable source, rather than collecting in the field or forest.
Agaricus campestris
Agaricus campestris, field mushroom, meadow mushroom (US), "pink bottom", similar to the common mushroom Agaricus bisporus, white fleshy mushroom
has stocky structure, grows after rains in fields, early growth may have a ring around the stem , North America and Europe, Agaricaceae.
Experiment
See diagram 9.201: Agaricus campestris
Examine the reproductive portion of a field 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.
Agaricus bisporus common mushroom, ('Portobello' mature mushroom), table mushroom, button mushroom, white mushroom, cultivated mushroom, Swiss brown mushroom, greyish-brown in natural habitat, hemispherical cap flattens it grows up to 15 cm, pink-brown gills, North America and Europe, Agaricaceae.
Cep mushroom, (Boletus edulis), pennybun, porcino, steinpitz, associates with spruce trees, large mushroom, up to 30 cm, greasy brown cap, swollen stem, hard to cultivate, Europe, Boletaceae.
Cantharellus cibarius, chanterelle, yellow chanterelle
Lingzhi mushroom, (Ganoderma lucidum), white rot, ling zhi mushroom, reishi mushroom, bracket fungi, herbal medicine, East Asia, Ganodermataceae.
Dried Reishi Mushroom Powder, Mudbrick Herb Cottage.
Urban valley Mushrooms, gourmet mushrooms, Brisbane
Stinky squid, (Pseudocolus fusiformis), a stinkhorn mushroom in the Phallaceae, United States, Australia, Japan, Java, and the Philippines.
Maitake mushroom, (Grifola frondosa), dancing mushroom, signorina mushroom, hen-of-the-woods, sheep's head, polyspore bracket
mushroom, grows at base of oak trees, perennial, but when older is inedible, Meripilaceae, China.
Dried herb sold as sliced mushroom or mushroom powder.
Shiitake mushroom, (Lentinula edodes), Chinese black mushroom, China, Marasmiaceae.
Lentinula edodes, Shiitake mushroom, Daleys Fruit Tree Nursery
Dried herb sold as fungus powder and fungus sliced.
Poisonous mushrooms
Amanita mushroom, Family Amarantaceae
Amanita muscaria, fly agaric, white flecked cap turns orange when dry, poisonous, hallucogenic (contains muscimol), herbal medicine if boiled, Amanitaceae.
Amanita muscaria, fly agaric, Agaricomycetes, large white-gilled, white-spotted, usually red mushroom in birch, pines, Nothofagus, world wide, poisonous
See diagram Amanita muscaria.
Amanita flavella# grows solitary in soil, pale yellow, globose juvenile fruit bodies, up to 90 mm with bulbous base in a sack, musghroom smell
.
Armillaria, Family Physalacriaceae
Armillaria ostoyae, honey mushroom, , good flavour, common in hardwood and conifer wood in the US, luminescent, huge underground mass
Armillaria, armillaria root rot of strawberries, woody ornamentals Calvatia, giant puffball mushroom Coprinus, on dung pads Crucibulum laeve, bird's nest fungus .
Armillaria,
Psilocybe cubensis (Stropharia cubensis), contains psilocybin and psilocin, called "boomers", "cubes", "gold caps".
Psilocybe semilanceata, contains psilocybin and baeocystin, called "liberty cap", "magic mushroom", "conical cap".
9.5.0 Not "true fungi"
9.1.8 Aspergillus
9.5.1 Deuteromycota
9.5.2 Hyphochtridiomycota
9.5.3 Microsporidia
9.5.4 Mycetozoa
9.5.5 Myxomycota
9.5.6 Oomycota
9.5.7 Peronospora
9.5.8 Phycomycetes
9.5.9 Physarum
9.5.10 Phytophthora
9.5.11 Pythium
9.6.0 Penicillium
Benzyl penicillin sodium salt, penicillin G, antibiotic
4.1.6 Antibiotics, penicillin, Safety in school science
16.2.4 Cheese making
Broad spectrum antibiotic penicillin preparations, Amoxillin (Amoxil, Augmentin), Ampicillin (Magnapen, Penbritin)
16.3.4.0.3 Lactams
Penicillin, lactams, -NH(CO-), caprolactam (6-hexanelactam) C6H11NO:
Penicillin G (benzyl penicillin), administered by injection
Penicillin V (phenoxymethyl penicillin), administered orally
See diagram 14.04 Penicillin
4.1.1 Colonies of different micro-organisms, Penicillium roquefort
4.1.5 Safe microscopy of Penicillium camemberti
Aminoglycosides, class of antibiotics
Amoxillin, "Amox", antibiotic for children
4.1.6 Antibiotics, penicillin, Safety in school science
Benzyl penicillin sodium salt, penicillin G, antibiotic
Cefrazidime, C22H22N6S2, cephalosporin antibiotic
7.9.14.2 Chloramphenicol
4.8 Gram-negative facultative anaerobic rods (See: Klebsiella pneumoniae)
16.3.4.0.3 Lactams
Micromonospora
Neomycin, antibiotic, from Streptomyces fradiae
Nisin, E234 (antibiotic from bacteria, from beer) (preservative) (in processed cheese, tomato sauce), food additive
Oxacillin, penicillinase-resistant β-lactam antibiotic, replacing methicillin
16.3.2.7 Polyketides, polyketide antibiotics
Streptomyces griseus, earth odour of soil, produces streptomycin antibiotic
Experiments
9.6.7 Penicillium on rotten fruit and lemon
4.1.9 Prepare a spread plate, lawn plate
4.1.7 Prepare streptomycin using Streptomyces griseus
2.4.0 "Safety in the microbiology laboratory", by Eleanor Gough (See: 3.)
4.1.2 Spillage, Safety in school science
4.1.8 Microbial decomposition of cigarette paper
4.3.0 "Ten Rules for Safe Microbiology and Biotechnology in School" (See rule 6.)
9.6.7 Penicillium on rotten fruit and lemon
1. 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 fungus.
2. Lemon, Penicillium
Put a clean lemon cut in half in a clean colourless plastic container with a tight lid.
Add drops of water.
Wrap the plastic container in a sheet of plastic or aluminium foil and leave it in a dark place for one week.
Look at the lemon in the plastic container without opening it.
Observe the green mould of Penicillium growing on the lemon.
Dispose of the container in the garbage without opening the container.
9.7.0 Yeasts
9.206.3 Brewing, Yeasts, (Experiments)
Yeasts, Phylum Ascomycota, Saccharomyces cerevisiae
9.6.18 Alcoholic fermentation, yeast, Saccharomyces cerevisiae
9.1.2 Ascomycota, Phylum Ascomycota, (sac fungi)
4.3.7 Breakdown of protein by micro-organisms
9.7.1 Brewer's yeast powder
9.145 Brix, sucrose concentration
3.38 Carbon dioxide and fermentation for brewing
4.1.2 Enrichment of wild yeast strains, Aspergillus niger
12.1.20 Ferment sugar with yeast
17.4.2 Fermentation using yeast
4.1.1 Fermentation, Safety in school science
9.7.2 Ginger beer "plant"
9.158 Heat of respiration, bakers' yeast (Saccharomyces cerevisiae)
17.3.1.1 Hydrogen peroxide with yeast, elephant's toothpaste reaction
19.1.6.0 Leavening agents (See 3.)
4.2.4 Make wine from grape juice and make vinegar from wine
4.3.21 Micro-organisms and personal hygiene
9.7.3 Mycoderma, Phylum Ascomycota
4.3.8 Prepare alcohol using immobilized yeast cells
4.2.3 Prepare lactic acid with sourdough
9.7.4 Prepare a yeast culture
9.7.5 Monascus purpureus, (red yeast rice), Ascomycota
9.7.6 Saccharomyces species
9.7.7 Sampling yeast populations
9.3.12 Tests for zymase and catalase in yeast
10.2.33 Triple scale wine hydrometer
9.7.8 Use yeast to make bread
9.7.9 Wild yeasts in flowers
3.35.4 Yeast cells convert glucose to carbon dioxide gas and alcohol
16.7.3 Yeast, fermentation, brewing, beer:
9.7.10 Yeast population, bakers' yeast
9.7.11 Yeast and population limiting factors
9.1.1 Fungi Kingdom
Fungi (Singular: fungus), are a large group of eukaryotic organisms with over 100, 000 named species, but less than 500 can cause disease in otherwise healthy persons.
They are usually saprophytes in the soil and on decomposing organic matter.
Their cells are encased in a rigid cell wall composed of polysaccharides, e.g. glucan, mannan, chitin and glycoproteins.
They are heterotrophic so they have no chlorophyll and feed by secreting enzymes for external digestion and absorbing nutrients through their cell walls.
They have a simple structure with no division of cells into organs or tissues.
The basic structural unit is either a chain of tubular, filament-like cells, called a hypha, or an independent single cell, called a yeast.
Pathogenic fungi may change their growth form during tissue invasions.
They usually change from a multicellular hypha form in the natural environment to a budding, single-celled yeast form in tissue.
The vegetative stage consists of a mass of branching hyphae called a mycelium.
Each hypha has a rigid cell wall that increases in length by of apical extension with mitotic cell division.
Most hyphae are septate, partitioned by cross walls.
Moulds are fungi with a microscopic multicellular mycelium.
The fungi that exist as independent single cells, the yeasts, propagate by asexual budding where the cell develops a protuberance from its surface.
The bud enlarges and either becomes detached as a separate cell or remains attached and produces another bud to form chain of cells.
Some yeasts reproduce by fission of the cells.
Moulds reproduce by means of microscopic conidia, spores.
Many fungi produce conidia that result from an asexual process involving mitosis that are identical to the parent.
They are short-lived and are produced in large numbers to ensure dispersion to new habitats.
Many fungi are also capable of sexual reproduction involving meiosis.
Some species are self-fertile and can form sexual structures within individual colonies, but most do not form their sexual structures, unless two different mating strains come into contact so meiosis then leads to the production of sexual spores.
The sexual spores may be borne singly on specialized generative cells, so the whole structure is microscopic in size, but they also may be produced in millions to form fruiting bodies, e.g. mushrooms.
Fungi can produce more than one type of spore, depending on the growth conditions and the species.
Sexual reproduction and the accompanying structures form the basis for the classification of fungi.
9.1.2 Phylum Ascomycota
Phylum Ascomycota, Ascomycetes, ascus-producing fungi, sac fungi in truffles, yeast, morels, powdery mildew
Aspergillius
Claviceps
Aleuria, orange peel cup fungus
Bacillus subtilis
Alternaria species
Alternaria alternata, causes early blight of potatoes, ink disease of "kangaroo paws" plant, respiratory diseases.
Alternaria citri, causes brown spot of mandarin.
Alternaria dauci and Alternaria radicina, causes leaf blight of carrot.
Alternaria helianthi, causes seedling blight of sunflowers.
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 phalloides, death cap mushroom, agaric mushroom, fly agaric, poisonous toadstool, muscimol, muscimole, muscarine,
mycorrhizal association with oaks, if consumed causes nausea then attacks the liver and other organs
Armillariella mellea, honey fungus
Fusicladium carpophilum, Ascomycota, causes freckle disease on stone fruit, e.g. apricot, peach.
Glomerella cingulata, Ascomycota, causes anthracnose disease of avocado, bitter rot of apple, camellia die back.
Histoplasma capsulatum, Ascomycota, causes Darling's disease from bird or bat droppings.
Leptosphaeria maculans, Ascomycota, causes black leg of crucifers, e.g. cabbage.
Marssonina rosae, Ascomycota, causes black spot disease of rose.
Omphalotus nidiformis, ghost fungus, poisonous
Agaricus xanthodermus, yellow stainers, poisonous
Chlorophyllum molybdites, causes vomiting
9.1.3 Phylum Basidiomycota
Phylum Basidiomycota, basidiomycetes, basidium-producing fungi, club fungi, mushroom. toadstool, smuts, rusts,
sexual spores are produced on a club-shaped basidium,
e.g. Agarics, gill fungi Boletes | fleshy pore fungi Clavarias | coral-like fungi Gasteronmycetes | puff ball fungi , body ruptures to release spores
Hynoids | spine fungi Puccinia | wheat rust Phalloids | stinkhorn fungi Polypores | bracket fungi Tholopores | leather shelf fungi Tremellales |
jelly-like fungi Ustilago | .
9.1.4 Phylum Chytridiomycota
Chytridiomycetes, chytrids, Algae: Heterokontophyta zoosporic fungi, aquatic fungi, asexual, single cilium, saprophytic
9.0.3 Phylum Heterokontophyta
Allomyces Batrachochytrium, kills frogs Chytriomyces Monoblepharis Rhizophydium Synchytrium endobioticum, potato wart disease, black scab
9.1.5 Phylum Glomeromycota
Glomerales, mycorrhizal associations, arbuscular (lives inside plant cells), mutualistic
Acaulospora, Geosiphon, Glomus, Pacispora, Paraglomus, Physoderma, Siphonaria
9.1.6 Phylum Zygomycota
Zygomycetes, phaecomycota, phycomycetes, have no cross-walls (septa).
Encephalitozoon cuniculi, causes diarrhoea in AIDS patients.
9.1.7 Mitosporic fungi (fungi imperfecti)
Formerly "Deuteromycota " or "fungi imperfecti", because no sexual reproduction had been observed, 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", e.g. Tinea pedis.
9.1.8 Aspergillus, Ascomycota
The spores of Aspergillus may be harmful if students inhale them.
Aspergillus flavus (and Aspergillus parasiticus) produce aflatoxins, toxic and carcinogenic mycotoxins.
Aspergillus flavus and Aspergillus parasiticus may produce aflatoxins in copra that is not dried or not stored properly.
Aspergillus
6.5 Prepare Czapek Dox Agar
4.1.2 Enrichment of wild yeast strains, Aspergillus niger
16.3.1.8 Pectin, See: Aspergillus japonicus
16.3.2.7 Polyketides, polyketide antibiotics
9.3.10 Tests for diastase activity
16.3.8.3 Tricarboxylic acids, citric acid, See: Aspergillus niger
Experiments
Agaricus campestris, field mushroom
Eurotium
4.3.4 Find and grow micro-organisms
Mucor mucedo, cheese-making
Penicillium on lemon
4.1.5 Safe microscopy of Penicillium camemberti
4.1.1 Colonies of different micro-organisms, Penicillium roquefort
4.1.5 Safe microscopy of Penicillium camemberti
9.1.9 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.
These moulds are mostly harmless, but Phoma may cause allergies.
They can be cleaned off with bleach solutions.
9.1.10 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 that 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.
Cellulases are used in the processing of fruit and vegetables to destroy the cell walls.
9.1.11 Cork taint of wine, "corky" wine
See 16.1.3.2: 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, Cl3C6H2OCH3, (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, Fagaceae.
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 to seal wine bottles, 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 the cork 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 cork shrinkage.
Brandy
However, fortified wines, e.g. sherry and port, have brandy, a strong spirit distilled from wine, 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 traditionally stored upright to avoid any corky taste, yet allow some oxidation.
9.1.12 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.
Creolin, disinfectant, insecticide, miticide, contains: coal tars, isopropyl alcohol, phenol, sodium hydroxide.
Antibiotics are produced by microbes as a natural defence against other microbes.
Some are still produced 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, e.g. lysosyme in sweat and tears.
Plant materials such as garlic (Allium sativum), and oil of clove(Syzygium aromaticum), also have antimicrobial properties.
Tea tree oil, Melaleuca alternifolia, Myrtaceae
9.1.13 Fungal infections of humans
Fungal infections of humans are rare, except from Candida and Aspergillus.
Yeasts and moulds can effect predisposition to infectious disease.
Moulds can form mycotoxins, e.g. aflatoxins.
Infections caused by fungi include superficial infections of the skin or mucous membranes, e.g. yeast vaginitis, oral thrush, athletes foot and rare systemic infections in the bloodstream of a person with a weak immune system.
* Candida, Ascomycota, Class: Saccharomycetes, Order: Saccharomycetales, Family: Saccharomycetaceae
10.10.2 Candidiasis (Thrush), Candida albicans
4.1.7 Prepare streptomycin using Streptomyces griseus
Blastomycosis Candidiasis, Candida species, lung infection
The Candida yeast is common, but it may cause infections in the mouth, the gut, and the female reproductive system (Candida vaginitis).
Candida krusei, is known to be a food spoilage organism.
* Pneumocystis pneumonia fungus (PCP) is an opportunistic infection of HIV patients and malnourished children.
* Paracoccidioidomycosis: Pityrosporum ovale (overgrowth causes dandruff)
* 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)
9.1.14 Rhizoctonia, Basidiomycota
Rhizoctonia leguminicola, red patch disease of red clover, brown patch of lawn grass, "damping-off" disease of seedlings
Rhizoctonia solani, collar rot of beans
See website: Rhizoctonia
9.1.15 Rhizopus nigricans, mouldy bread, Phylum Zygomycota
Rhizopus genera have stolons, pigmented rhizoids, sporangiophores from nodes above rhizoids, dense white to brown, cotton-like.
Rhizopus nigricans, bread mould, stolonifer black bread mould, is a common mould on bread.
Rhizopus oryzae (R. arrhizuz), is used for fermentation of foods, making Japanese sake.
See diagram 9.196.1: Rhizopus oryzae
Rhizopus oligosporus, ferments soya beans to make tempe.
Rhizopus sexualis is used to study linear growth.
Rhizopus stolonifer produces lipase.
9.1.16 Rusts, Puccinnia species, wheat rust
Puccinia triticina, wheat stem rust
Puccinia graminis, soybean rust
Phakopsora, white pine blister rust, apple cedar rust, hollyhock rust, asparagus rust, white pine blister rust
Plant rusts, Basidiomycota, Subphylum Pucciniomycotina, Order Pucciniales (was Uredinales) are plant parasites that need a living host plant in their life cycle.
They are called "rusts", because of the powdery yellow rust-coloured coating on host vegetation, which the rusts stunt their growth rather than kill them.
9.1.17 Smuts, Phylum Basidiomycota, Class Ustilaginomycetes
16.8.8 Corn smut (fungus)
16.8.9 Head smut (fungus)
9.1.18 Stinkhorns, e.g. Phallus
Family Phallaceae:
Aseraöe rubra, Clathrus, Colus, Dictyophora, Laterna, Leucocoprinus birnbaumii, Lysurus mokusin,
Phallus impudicus, looks like yellow morel.
Polyporus stolonifera, bread mould
9.1.19 Tuber melanosporum, black truffles
Black truffle, Périgord truffle, French black truffle, has a wart-like brown epidermis with red reflections.
The tuber is marbled with white on anthracite base colour, has aroma of forest undergrowth and damp earth with roasted dry fruits.
The taste can be described as finely peppered and long in the mouth.
The Perigord is the finest grade of black truffle.
The French Black Truffle is the fruiting body of the fungus (Tuber Melanosporum) that forms a symbiotic relationship with the roots of oak or hazel trees on which it grows.
The edible portion, called the truffle, is harvested in winter once it has matured and is emitting a sweet perfume.
The truffles are found from just below the soil surface to a depth of 20 cm by specially trained dogs or pigs, spaniels in Australia.
A French black truffle, 2 cm diameter to grapefruit size, is covered in small black corrugations like the texture to a dog's nose.
It has a shelf life off approximately three weeks after harvesting before it loses its distinctive taste and aroma.
It forms in Spring in Australia between December to February.
At first it has the form of a tiny cup shape, of which the edges will close up and form the truffle.
The interior of the truffle will grow tiny veins, it is white internally and the skin is a reddish colour with small warts on the outer layer.
As the truffle matures in June/September it changes to black inside with white veins, then it emits its powerful aroma.
The fungi requires a warm moist period in early spring to trigger initiation of the fruiting body.
Over the past 10 years, Australian prices have varied from $2000 per kg down to around $1200 per kg for first grade truffles.
The trufferies are situated near Deloraine, Tasmania, Australia, and are quarantine areas with strict control over visitors enforced to ensure that any potential competing fungi are not introduced.
If fresh eggs are stored with truffles for a few days, the yolks will become infused with truffle aroma.
Truffle Discovery Centre, Stanthorpe, Queensland
9.1.21/a> Slide culture preparation to identify fungi
See diagram 9.208: Simple agar block
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 × 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.
9.2.1 Antibiotics by name
Amoxicillin, C16H19N3O5S
Azithromycin C38H72N2O12
Cephalexin, C16H17N3O4S
Ciprofloxacin, C17H18FN3O3
Clavulanate C8H9NO5 combined with Amoxicillin
Clindamycin C18H33ClN2O5S
Doxycycline, C22H24N2O8
Metronidazole C6H9N3O3
Sulfamethoxazole C10H11N3O3S
Trimethoprim C14H18N4O3
9.2.2 Antibiotic consumption
Antibiotic consumption in order of use in hospitals
Antimicrobial class (ATC code):
Tetracyclines (J01 AA),
Penicillins with extended spectrum (J01CA),
Beta-lactamase-sensitive penicillins (J01CE),
Beta-lactamnase-resistant penicillins (J01CF),
Penicillins with beta-lactamase inhibitors (J01CR),
First-generation cephalosporins (J01DB),
Second-generation cephalosporins (J01DC),
Third-generation cephalosporins (J01DD),
Fourth-generation cephalosporins (J01DE),
Monobactams (J01DF),
Carbapenems (J01DH),
Trimethoprim (J01EA),
Sulfonamides (J01EC),
Trimethoprim with sulphonamides (J01EE),
Macrolides (J01FA),
Lincosamides (J01FF),
Aminoglycosides (J01GB),
Fluororoquinolones (J01MA),
Glycopeptides (J01XA),
Polymyxins (J01XB),
Fusidic acid (J01XC),
Imidazoles (J01XD),
Nitrofurans (J01XE)
9.2.3 Antibiotic resistance in the world
According to the WHO, multi-drug resistant TB causes more than 150, 000 deaths every year to which must be added the hundreds of thousands who die around the world every year from antibiotic resistant infections.
Antibiotics were once the wonder drug heralding a new phase of public health.
Drug resistance has been known for decades and usually arises when antibiotic drugs knock out susceptible infections, sometimes leaving active strains behind that can multiply and become extremely resilient.
In the past, this did not prove much of a problem as new antibiotics always appeared, but we are now facing is that the supply of new antibiotics has dried up.
While there has been some attempt to rein in our overuse of antibiotic drugs, there really hasn't been a concentrated campaign to do the same for the use of antibiotics in our livestock and foodstuffs.
9.2.4 Chloramphenicol, C11H12Cl2N2O5
Chloramphenicol, amphicol, harmful if ingested, broad-acting natural and synthetic antibiotic, interferes with bacterial protein synthesis, is used to treat eye infections, but may have severe side effects.
Chloramphenicol, the first broad-spectrum antibiotic manufactured synthetically, was isolated from Streptomyces venezuelae, a species of filamentous soil Gram-positive bacterium which produce spores above ground and in the soil.
9.2.32 DRBC (food spoilage medium).
9.5.1 Deuteromycota, (fungi imperfecti)
Deuteromycota was formerly a phylum, or fungi imperfecti, (now called the "mitosporic fungi")
Deuteromycota are Ascomycota and Basidiomycota in which sexual reproduction is unknown, e.g. Arthrobotrys.
9.5.2 Hyphochtridiomycota
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.).
9.7.01 Kingdom Chromista
9.0.2 Phylum Heterokontophyta, e.g. Aimillaria, Lactarius, Tremella
9.5.3 Microsporidia
Tiny parasites with no mitochondria
Loma in fish, Abelspora in crab, Amblyspora in mosquito
9.5.4 Mycetozoa
Slime moulds may be acellular or plasmodial or coenocytic.
The unit is a plasmodium, slime fungus, fungus-like slime moulds, also called scrambled egg mould, dog vomit mould, feed on decaying matter, not toxic. but leave patches in lawns.
9.5.5 Myxomycota
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
9.0.17 Slime moulds, Myxomycota
Fuligo, yellow slime mould, Protista, Mycetozoa
Sternonitis, Protista, Mycetozoa
9.5.6 Oomycota
Oomycota, oomycetes, water mould, egg fungi, but it is not a fungus, but is similar to brown algae.
The zoospores have two cilia.
Oomycetes are nowadays usually classified under the Heterokontophyta division of the Algae, or put in the Kingdom Chromista.
9.7.01 Kingdom Chromista
9.0.2 Phylum Heterokontophyta
Albugo, Phylum Oomycota
Albugo candida (Cystopus ), water mould, white rust Bremia lactucae, downy mildew of lettuce Monoblepharis
Plasmopara viticola, downy mildew of grape, Phylum Oomycota
Saprolegnia, water mould, cotton mould
23.2.1 Black pod disease, Cocoa Project
5.11.1 Coconut bud rot, Coconut Project
13.3.9 Damping off fungus, Papaya Project
9.5.7 Peronospora, Phylum Oomycota
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
Downy mildew (Peronospora belbahrii), may be seed-borne, so ensure seed comes from disease-free crops and control the disease in seedbeds.
Downy mildews are a common problem in the UK, major threat to lettuce crops, so genetic resistance and routine fungicide application is used.
There is no known resistance in basil, so in New Zealand and Australia, it is controlled in the seedbed and in the field with metalaxyl M or cheaper potassium phosphate.
9.5.8 Phycomycetes, the algae-like fungi
A former classification system, which included Mucor, Rhizopus, Albugo, Saprolegnia.
Phycomycetes have aseptate hyphae, coenocytic hyphae, i.e. the mycelia have no septa, so no distinct cells, and nuclei are all together.
9.5.9 Physarum
Physarum, many headed slime, "pet slime mould", Protista, Mycetozoa
Plasmodiophoromycota Dictysteliomycota Acrasiomycota
9.5.10 Phytophthora, water mould, Phylum Oomycota.
Phytophthora are not called Fungi, because they have cellulose cell walls, whereas fungi have chitin cell walls.
Have diploid chromosomes in non-reproductive stage (fungi haploid cells).
Have hyphae that lack cross walls, coenocytic hyphae and they have two types of flagella.
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 passionfruit
Phytophthora infestans, causes cocoa black pod
Phytophthora capsici, infects cucumbers and squash
Phytophthora cinnamomi, causes cinnamon root rot affecting hemlock, juniper, eucalypt, banksia
Phytophthora citricola, causes root rot and stem cankers in citrus trees
Phytophthora fragariae, causes red root rot affecting strawberries
Phytophthora infestans, causes potato (late) bligh, the Great Famine of Ireland
Phytophthora megakarya, causes cocoa black pod disease
Phytophthora palmivora, causes fruit rot in coconut and betel nut
Phytophthora sojae, causes soybean root rot
Experiment
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.
9.5.11 Pythium
Pythium, root rot, "damping-off" fungus, Family Pytheaceae, 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 (geranium).
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
Experiment
Observe Pythium under the low and high powers.
Study prepared slides of the asexual and sexual methods of reproductio
9.6.6 Rhizopus nigricans, bread mould
See diagram 9.196: Rhizopus nigricans
Experiments
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.
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.
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.
2. Label 4 plastic bags with zippers as bag 1, bag 2, bag 3, and bag 4, e.g. Ziploc plastic bags.
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.
Do not open the plastic bags if they contain the bread mould, but keep them sealed and dispose of them in the garbage.
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.
3. Use 10 slices of white sliced bread from the same loaf.
Use a knife to cut the slices into 10 × 10 cm squares.
Leave the squares on the bench for one day.
Put each square flat in a sealable sandwich bag, e.g. ziploc
Leave 3 bags on the bench, but cover them with a dark cloth to exclude light.
Put 3 bags in a refrigerator and 3 bags in a refrigerator freezer.
Draw a 10 × 10 cm grid on clear plastic.
Every 24 hours, for about 10 days, use the plastic grid to count the number of square centimetres of mould on each square of bread.
Do not open the bags.
When you have enough observations, discard all of the bags without opening them.
Calculate the average area of mould grown for the 3 treatments, bench, refrigerator, freezer.
4. 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.
5. Test clove oil.
Soak circles of filter paper cut with hole puncher in clove oil.
Seal a slice of bread in a plastic bag with a few drops of water and wait a few days until the (dark green to black) black mould forms on the bread.
Shake the mouldy bread in water to form a mould solution.
Place the mould solution on a nutrient agar plate and incubate for a while.
Drop filter paper circles on the mould.
The clove oil-impregnated filter paper square kills the mould.
9.7.1 Brewer's yeast powder
This nutritional supplement, derived from Saccharomyces cerevisiae, is a said to provide a rich supply of protein, B-complex vitamins and minerals.
9.7.2 Ginger beer "plant"
Making ginger beer using yeasts, can manipulate many variables, especially those affecting enzyme activity (temperature, pH, heavy metals or other enzyme-targetting poisons, or those affecting the type of respiration occurring, i.e. aerobic or anaerobic (access to outside air or measured oxygen supply) and so getting different alcohol
level outcomes.
Ginger beer "plant" is the yeast Saccharomyces florentinus (S. pyriformis), and the bacterium Lactobacillus hilgardii (Brevibacterium vermiforme), a symbiotic colony of yeast and bacteria.
Ginger beer soft drink is made from ginger powder and does not contain alcohol.
Some people use baker's yeast or 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.
A "real" ginger beer plant is called a "scoby", a symbiotic colony of bacteria and yeast, not baker / brewer's yeast) may be purchased.
It must be used in a shorter time frame.
See : www.gingerbeerplant.net.
9.3.1 SCOBY, Symbiotic Colony Of Bacteria and Yeast
Experiments
1. 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.
2. In a plastic container, put 8 sultanas, juice of 2 lemons, 1 teaspoon (5 mL) lemon pulp, 4 teaspoons sugar, 2 teaspoons ground ginger, 2 cups (500 mL) cold water.
Cover and leave for 2-3 days to allow fermentation to start.
The each day for one week add 2 teaspoons of ground ginger.
The "plant" should now be ready to make the ginger beer.
Use 4 cups sugar dissolved in 4 cups boiling water, and add juice of 4 lemons.
Add this to the plant + 30 cups of cold water.
Put into bottles and leave for 2 weeks before drinking.
3. To make simple cold water ginger beer use 4 cups sugar, 1 tablespoon ground ginger, juice of 4 lemons + 5 litres of cold water.
Stir until sugar is dissolved, strain and put into bottles with 3 sultanas in each bottle.
Put into bottles and leave for one week before drinking.
4. Create what is called a "ginger beer plant".
Put 15g of general purpose dried yeast into a large jar or bowl, add 300 mL water, 2 teaspoons ground ginger and 2 teaspoons sugar.
Cover with a sheet of cling film and secure with a rubber band.
Each day, for seven days, add 1 teaspoon of ginger and 1 teaspoon of sugar to the mixture in the jar.
Now strain the mixture through a piece of fine muslin and add the juice of two lemons to the liquid.
Add 50g or sugar to the liquid and make up to 4.5 litres with cold water, stirring to dissolve the sugar.
Put into a plastic bottle.
Keep for 7-10 days when the ginger beer is sparkling and ready for drinking.
Keep the sediment that you have left after straining the ginger beer plant.
Divide into two jars and give 1 plant away to a friend with the instructions.
To the sediment add 300 mL water, 2 teaspoons sugar and 2 teaspoons ginger and carry on as before.
9.7.3 Mycoderma
Mycoderma aceti (Ascomycota), produces acetic acid (vinegar), from fermenting wine or malt infusion.
9.7.4 Prepare a yeast culture.
Use 3 unpeeled potatoes, hops, 1 tablespoon (15-20 mL) flour, 1 tablespoon sugar, 1 teaspoon (5 mL) salt.
Boil potatoes and hops in 500 mL water for 30 minutes.
Strain away the water and keep it as hop water.
Blend flour, sugar and hop water until smooth, stir into the strained hops and potatoes, then add salt.
Put into secure container and yeasts should be ready for use in 8 hours.
9.7.5 Monascus purpureus, (red yeast rice), Ascomycota
It is used to produce red-purple fermented rice called "red yeast rice", Chinese brand names "Xuezhikang (XZK)" or "Hypocol".
Red yeast rice is used for food colouring, e.g. Peking duck and pickled tofu, and is a Chinese herbal medicine.
It may reduce the chance of repeated heart attacks after surgery better than other statins, but it may cause liver damage.
9.8.0 Fungi 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, is an oats pathogen.
Kluyveromyces lactis, ferments lactose, produces chymosin, rennet.
Leptosphaeria maculans, is a Brassica pathogen.
Myrothecium verucaria, digests cellulose.
Phaffia rhodozyma, red yeast, is 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, is the edible oyster cap mushroom.
Rhodutorula rubra, has coloured yeast colony.
Rhytisma acerinum, lesions on sycamore leaves indicates air pollution.
Saprolegnia litoralis, is a parasite of pond animals.
Schizosaccharomyces, has large cells that divide by binary fission.
Selerotinia fructigena (Monilinia fructigena) causes apple brown rot.
Sordaria fimicola, is used to study meiosis in fungi.
Sordaria brevicollis, is used to study meiosis in fungi.
Sporobolomyces, grows on leaf surfaces, spores are forcibly ejected.
Trichoderma reesei, is used for production of cellulase.
Trichoderma viride, decomposes cellulose.
9.7.6 Saccharomyces species
Bakers' yeast, Saccharomyces cerevisiae, but different strain called Brewer's yeast.
Beer yeast that tolerates high ethanol concentration, Saccharomyces ellipsoideus
Wine yeast, Saccharomyces ludwigii, Saccharomyces minor
Grape yeast, Saccharomyces pastorianus
Yeast grows on starch and produces glucoamylase, Saccharomyces diastaticus
Wild yeast, Saccharomyces exiguus ( minor), is used in sourdough.
9.7.7 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 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.
5. Population density of yeast
Use brewer’s yeast to investigate the effects of different sugars or temperatures on population density.
Use a haemocytometer to calculate population numbers over 4 days.
Time needed includes lunch times, before school and lessons spent counting yeast and mastering the skills of using the haemocytometer.
9.7.8 Use yeast to make bread.
Use 1 cup of yeast, 2 kg flour, 1 tablespoon of salt.
Sift the flour into a pile, scoop out the centre of the pile and add fold the mixture thoroughly to make a batter.
Keep in a warm place until the next day.
Add warm water to just moisten the batter to form a dough on a board.
Knead the dough until it ceases to stick to the hands or the board.
Leave and put it into greased baking tins.
Leave the full tins for 30 minutes, then bake in a moderate oven for 45-60 minutes.
9.7.9 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.
9.7.10 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.
Brewer's yeast, sold as a powder that has been debittered, can be taken as a nutritional supplement, because of its rich supply of protein, B-complex vitamins and minerals.
Experiments
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.
9.7.11 Yeast and population limiting factors
Normally, population increase is kept in check by the carrying capacity (resources available) of the environment.
During this laboratory session, you will explore the growth of yeast populations in a simple ecosystem (a test tube).
Optical density 600 (OD600) will be measured using a spectrophotometer and that will be used as a proxy for population.
Research Question: What is the effect of amount of food resources on population change?
Materials:
* 2% sucrose solution
* Distilled water
* Yeast solution (7g/50mL)
* 2x medium test tubes
* Cotton wool
* 10 mL measuring cylinder
* 3x Bulb pipettes
* 2x cuvette
Method:
Set-up
1. Label the two test tubes with your group name and the letters A and B.
2. Into test tube A, use the measuring cylinder to add 10mL of distilled water.
3. Into test tube B, use the measuring cylinder to add 10mL of 2% sucrose solution.
4. Using the bulb pipette, add 3 drops of the yeast solution to each test tube.
5. Swirl each test tube to mix.
Do not shake.
6. Using a clean bulb pipette take a 1mL sample from test tube A and place into a cuvette.
7. Set the spectrophotometer to 600nm and place the cuvette in with clear sides in the light path.
8. Close lid and record the reading in the table below.
9. Pour the sample back into the test tube and close with cotton wool.
10. Repeats steps 6-9 for test tube B.
Day 4 measurements
1. Using a clean bulb pipette suck up and eject back into test tube A to mix the solution.
2. Take a 1mL sample from test tube A and place into a cuvette.
3. Set the spectrophotometer to 600nm and place the cuvette in with clear sides in the light path.
4. Close lid and record the reading in the table below.
5. Pour the sample back into the test tube and close with cotton wool.
6. Repeats steps 1-5 for test tube B.
Results
Sample Initial (abs) Final (abs) Change (abs)
Test tube A (water)
Test tube B (2% sucrose)
Discussion 1. Describe the results and identify which test tube showed the greatest increase in population.
Use the data to support your answer.
2. Discuss whether these results are reliable and valid.
3. Identify one factor that impacts the reliability of these results and one that impacts validity.
4. Describe at least three modifications that could be made to this experiment to improve it.
Justify these modifications using the results.
Draw growth curves, calculate growth rate, determine carrying capacity.
Some teachers say that they have had mixed success with this experiment when students use it to investigate population growth.
Critical aspects are thorough sterilization of glassware, quality microscopes and effort in developing microscope skills.
Also ensuring adequate 'swirling' of the flasks before sampling helps stop clumping which can complicate counting.
Each year level varies in their ability to do this experiment.
Taking photos for counting helps, but you often find that the cells are spread across several levels when you use the fine focus at 400X.
We had starting counts of around 5-10 cells per 0.1mm square quadrat increasing to about 40 per quadrat then levelling off and declining over 72 to 96 hours.
The use of more cytometer slides would improve the results, but they are not easy to find.
9.9.0 Field fungi
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.
2. Collect different fungi in the field.
Toadstools are like little umbrellas growing out of the ground or rotten wood.
They may be poisonous and glow in the dark, e.g. Calvatia, Filoboletus.
Bracket fungi are hard and grow out of the trunk of trees, e.g. Pycnosporus.
Some fungi grow on cow dung, e.g. Pilobilus.
Some fungi are parasites that attack living things, e.g. diseases on the human skin and ear, and diseases of cocoa and peanuts may all be caused by fungi.
Yeasts are tiny fungi that cause fermentation of cocoa beans and are used to make beer.
Are fungi good or bad? [Fungi that are parasites are bad, because they cause disease, all the other fungi are good.]
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.]
Anthracnose, Colleothrichum sp.
"Anthracnose" is a general term describing fungal diseases which typically develop dark sunken spots or lesions, often with a raised rim.
Black fruiting bodies produce pink spores, especially in warm humid weather.
In Queensland, anthracnose is a common disease in horticulture, also known as pepper pot disease of avocado and degreening burn in citrus and blossom blight in mango.
Anthracnose is usually caused by Colleothrichum species, but also Diplocarpon species affects roses and Elsinoe species affects grapes.
Cercospora
Cercospora beticola causes cercospora leaf spot disease of silver beet.
Cercospora violae causes leaf spot of violet.
Cordyceps
Cordyceps militaris adenosine
Cordyceps sinensis, adenosine, caterpillar fungus, "summer grass", folk medicine to stimulate immune system in China, Tibet, Nepal
Cordyceps subsessilis, is a source of immunosuppressive ciclosporin.
Cordyceps unilateris, infects ants and changes their behaviour.
Didymella bryoniae, causes gummy stem blight of cucurbits, e.g. watermelon.
Diplocarpon
Diplocarpon mespili, causes fleck disease of pears and quinces.
Diplocarpon rosae, causes black spot disease of roses.
Drechslera turcica, causes leaf blight of sweet corn.
, causes tinea
Erysiphe , powdery mildew
Psilocin, C12H16N2O, Plant Amine
Psilocin, (4-Hydroxy-N, N-dimethyltryptamine), Psilocine, Psilotsin, tryptamine alkaloid, is derived from N, N-dimethyltryptamine).
It is a tertiary amino compound, a hydroxyindole, phenol, hallucinogenic alkaloid, serotonergic agonist, similar to seratonin.
It is a Schedule I drug under the Convention on Psychotropic Substances, and occurs in psychedelic mushroom Psilocybe mexicana (Teonanacatl), which forms from a blue pigment when bruised.
See diagram: Psilocin.
Psilocybin, C12H17N2O4P, Plant Amine
More than 200 species of mushrooms are known to produce psilocybin.
The psychoactive of "magic mushrooms" may be used for treating depression and post-traumatic stress disorder.
Psilocybin, psilocybine, psilocibin, is an indocybinnon-isoprene indole alkaloid, simple indole derivative, tryptamine alkaloid, a "prodrug" compound.
It occurs in Psilocybe spp. mushrooms, and is converted in the human body to anxiolytic and psychoactive psilocin, C12H16N2O.
It activates serotonin receptors in the CNS to mimic effects of serotonin, and resemble effects of LSD and mescaline.
Psilocybin has successfully been used in clinical trials to treat depression.
Psilocin is converted to Psilocybin by metabolic phosphorylation in the body.
The Health (Drugs and Poisons) Regulation 1996 (Queensland), prohibits the possession and use of psilocybin, including the Australian species, Psilocybe subaeruginosa.
Hallucinogenic drug, in psychedelic mushrooms: 11.11.9
See diagram: Psilocybin.
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 .
Sphaceloma fawcettii, causes citrus scab disease of lemon Taphrina deformans, causes leaf curl disease of peach, witches' broom .
Trichoderma is a soil mould .
Amanita species, Destroying Angel mushrooms, e.g. Amanita bisporigera, Amanitaceae.
They are hallucinogenic poisonous mushrooms, which have white stalks, caps and gills and in the wild may be confused with the edible mushrooms.
Aspergillus
Aspergillus, Division: Ascomycota, Class: Eurotiomycetes, Order: Eurotiales, Family: Trichocomaceae
See diagram: 9.203: Conidial head
Aspergillus flavus and Aspergillus parasiticus produce a toxic substance, an aflatoxin, causing liver failure in humans and cancer, and are common soil saprophytes, and pathogens of humans and animals.
Their scientific name is derived from the early work that discovered Aspergillus flavustoxins.
Actinomycosis, aspergillosis disease, is caused by Aspergillus species, a bloodstream infection.
Aflotoxins
Aflatoxins are carcinogens and mutagens produced particularly by Aspergillus species.
Aspergillus flavus and Aspergillus parasiticus are moulds that form cancerogenic Aflotoxin B1, (C17H12 O6) and B2 (C14H17O6).
Aspergillus parasiticus may also form cancerogenic toxic aflatoxins, Aflotoxin G1 and G2.
Aspergillus fungus causes Aspergillus asthma in patients with HIV infection, cancer and leukaemia.
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, black staining of white bathroom grouting that needs bleach and sodium bicarbonate for removal, produces citric acid, and is a common infection outside the ear drum, and is a common laboratory contaminant.
Aspergillus oryzae, is NOT suitable for use in schools, produces amylase, and is used to make Japanese rice wine, sake.
Blastomyces
Blastomyces dermatitidis, pathogen causes blastomycosis, pustules form on skin.
Cultures are biohazard to laboratory personnel!
Botrytis
Botrytis, Phylum: Ascomycota, Subphylum: Pezizomycotina, Class:
Leotiomycetes, Order: Helotiales, Family: Sclerotiniaceae
Genus: Botryotinia
Botryotinia allii causes neck rot of onion, often seen as a single brown,
inner layer when onion bulb cut transversely.
Botryotinia cinerea causes diseases of strawberry, grey mould of pear, lettuce,
grape, Pelargonium (geranium), rose, rotting fruits, and
is used to produce dessert wines, noble rot.
Botryotinia elliptica causes grey mould of lilies.
Botryotinia fabae causes bean plant disease.
Botryotinia gladiolorum causes botrytis leaf and flower spot of gladiolus.
Botryotinia tulipae causes brown spots on leaves and flowers of tulips.
Candida
Candida, Division: Ascomycota, Class: Saccharomycetes, Order: Saccharomycetales, Family: Saccharomycetaceae
Candida genus, (formerly Torulopsis), 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 and the oesophagus.
It is a 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.
However, some antibiotics cause Candida overgrowth in the intestines.
Candidiasis (candidosis) is 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 is an asexual yeast species used for the production of protein for food and fodder.
Claviceps
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 diethylamide, d-lysergic acid diethylamide, LSD], ingestion of fungus-contaminated rye grain causes ergot poisoning (ergotism)
6.19.0 Ergot poisoning, (in pigs)
Agroclavine called St Anthony's Fire, (SAF).
See 11.11.9.1: LSD
Colletotrichum , Anthracnose
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, also sunken spots or lesions on avocado, cashew, passionfruit.
Colletotrichum lindemuthianum, causes anthracnose disease of beans.
Colletotrichum musae, on banana
Colletotrichum orbiculare, causes anthracnose disease of cucurbits, e.g. cucumber, watermelon. rockmelon, honeydew
Colletotrichum trichellum, causes leaf spot of ivy.
Cryptococcus, Division Basidiomycota
Cryptococcus gatti, causes mass lesions in the lung and brain, C. neoformans, causes fungal meningitis.
Cryptococcus neoformans, causes cryptococcosis infection in the lungs and causes fungal meningitis in HIV-affected patients.
Elsinoe
Elsinoe ampelina, causes black spot of grapes.
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.
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, Phylum: Ascomycota, Class: Sordariomycetes, Order: Hypocreales, Family: Nectriaceae
1. Most Fusarium species are soil fungi, but some Fusarium species are plant pathogens, causing stem rot, root rot and fruit rot.
Fusarium graminearum, infects barley, causes red rust on wheat.
Fusarium solani, digests cellulose
2. Fusarium oxysporum, a common plant pathogen, causes Panama disease of bananas, fusarium wilt of carnation, cucurbits, daffodils, tomato, fusarium bulb rot of lily, fusarium yellows of gladiolus, fusarium patch of cool climate grass, and dangerous infections in human burns victims.
The banana root nematode (burrowing nematode, 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.
13.1 Banana root nematode (See: fusarium)
23.1.1 Cocoa capsid bugs (See: fusarium)
14.4 Comparing bacterial wilt and fusarium wilt (in bananas)
14.2 Panama disease (Fusarium wilt), Fusarium oxysporum
6.6.9 Tomato family (Solanaceae), (See: 1.1 fusarium wilt fungus)
Microsphaera
Microsphaera penicillata causes powdery mildew parasite on lilac (Syringa vulgaris).
Microsporum, Phylum Ascomycota
Microsporum audouinii and M. ferrugineum, cause non-inflammatory infections of the scalp (tinea capitis) especially in children.
Microsporum canis, causes ringworm, especially in children, who get the infection comes from cats and dogs.
Microsporum gallinae, causes "white comb" lesions in chickens.
Microsporum nanum, causes chronic non-inflammatory lesions in pigs, which may infect humans.
Mucor
Mucor species are is used in mould ripening cheese-making, but can also spoil the cheese.
Mucor genevensis and Mucor hiemalis are used to study sexual reproduction.
Mucor pusillus (Rhizomucor pusillus), is NOT suitable for use in schools.
Experiment: Mucor mucedo
Mucor mucedo is a black pin mould on bread.
See diagram 9.202: Penicillium, Mucor
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 -).
Mycosphaerella
Mycosphaerella causes leaf and pod spot of pea, and leaf spot of eucalyptus.
Mycosphaerella fijiensis, causes black Sigatoka disease of bananas: 14.3
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 and yellow sigatoka disease of bananas.
Penicillium
Penicillium species, Penicillin antibiotic, Phylum Ascomycota
Penicillium has brush-like conidiophores. (Latin peniculus brush).
Penicillium is a soil mould.
See diagram 9.202: Penicillium, Mucor
See diagram 9.202.1: Penicillium, branching conidiophores
Penicillium chysogenum (Penicillium notatum), has a yellow pigment, produces the penicillin antibiotic.
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.
Penicillium purpurogenum (Penicillium rubrum), is a plant pathogen.
Penicillium candida (Penicillium camemberti, Penicillium glaucum), produces antibiotics for production of cheeses, e.g. Camembert.
Penicillium roqueforti is used to make blue-veined cheese, e.g. Roquefort cheese.
Penicillium italicum and Penicillium olivaceum, are fruit parasites.
Penicillium expansum, causes apple disease.
Penicillium wortmanii, produces wortmannin, a commonly used cell biology reagent, used to research cell proliferation.
Peziza, Phylum Ascomycota, cup fungus, saprophytic in wood
Phallus impudicus, Basidiomycota, common stinkhorn, having foul-smelling spore masses.
Phoma foveata (Phoma exigua var. foveata), Ascomycota, causes gangrene of potato.
Phomopsis obscurans, Ascomycota, causes leaf blight of strawberry.
Phomopsis viticola, causes dead arm disease of grapes.
Pneumocystis jirovecci, Ascomycota, causes Pneumocystosis, which affects AIDS patients.
Trichophyton, Ringworm disease
Trichophyton species, as medical fungi, are generally classified as Trichophyton rubrum (downy type), and Trichophyton rubrum (granular type).
Trichophyton rubrum (downy type), has slender microconidia and no macroconidia and causes chronic infection of the skin and nails.
Trichophyton rubrum (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.
Trichophyton mentagrophytes causes tinea pedis, "athletes' foot", usually between the third and fourth toes of the feet.
4.9.1 Fungi diseases of plants
| 9.0.0 Fungi
Fungi can attack and digest green plants, and may live in the damp soil.
Leaf and stem fungus diseases appear as yellow or brown spots that may later join, then the leaf or stem dies.
Chemicals that kill fungi are called fungicides, e.g. "Captan".
Damping-off diseases
When seeds or seedlings are attacked by fungi or bacteria which live in the soil, the plant disease is called pre-emergence damping-off.
If the attack occurs after the seedling has appeared above the ground, the plant disease id called post-emergence damping-off.
The rot occurs at the base of the stem or in the roots and spreads upwards into the lower stem.
Damping off fungus disease attacks germinating seeds and makes all the seedlings fall over and die.
The fungi Pythium spp. and Phytophthora spp. commonly cause damping-off.
The fungus Rhizoctinia spp. may cause only the outer areas of the stem to rot, a condition called "wire-stem".
If fungi grow up the stems of seedlings to infect the leaves, brown threads appear where the Rhizoctinia spp. touch the soil.
Damping-off fungi can be avoided by making sure seedlings are not over- watered, overcrowded, damaged, or in a poorly drained medium.
Damping-off can be prevented by heating the soil to kill all the fungi before planting seeds - soil sterilization.
Collar rot diseases
Collar rot fungus disease attacks the stem near the ground, usually at an early stage of growth.
It may cause sunken areas near the ground on the young stems, soil particles sticking to threads in the sunken areas and wilting foliage.
Although collar rots may be called "rhizoctonia disease", on beans, other fungi, e.g. Phytophthora, and bacteria can cause collar rots.
Collar rots on trees, e.g. Citrus spp. may cause gum oozing out of the bark near the ground.
If this barks becomes brittle, it may indicate infection occurring around the stem, leading to ringbarking of the tree.
Powdery mildews diseases
Powdery mildews are first seen as faint white spots on leaves which increase in area until the whole leaf, or buds and fruit, are covered with a white powder.
Infected young leaves become distorted and fold, but not infected mature leaves.
Powdery mildew spores germinate during high humidity weather, rather than during rainy weather.
Powdery mildew looks like white threads on leaves or stems of pumpkins and cucumbers, criss-cross lines on red apples.
Powdery mildews may occur on grapes, papaya, strawberries.
Rusts diseases
Rusts diseases cause yellow spots on the upper surfaces of leaves and may be caused by many different fungi.
Some rusts stimulate the plant to form galls characteristic of that species of fungi.
Rusts occur on beans, carnations, chrysanthemums, geraniums, peach, raspberry and many grasses.
Wheat leaf rust (Puccinia triticina) spends part of its life cycle on wheat, Triticum aestivum, and part on barberry plants Berberis spp..
Pyocyanin, C13H10N2O, antibiotic pigment produced by Pseudomonas aeruginosa