Economic and cultural importance of Fungi

Fungi as food

Yeast fermentations, Saccaromyces cerevesiae

Glucose

+ 2 ATP

2 glyceraldehyde-3-phosphate

2 pyruvate + 2 ATP

+ 2 H2O

2 acetaldehyde + 2 ATP + 2 CO22 ethanol

2 NADH22 NAD O2

alcoholic beverages, yeast leavened bread

Fungi as food

Citric acid Aspergillus niger

Citric acid is an additive in many processed food products, mainly carbonated

soft drinks. Also used as an ingredient in cleaning agents.

Industrial production of citric acid uses the fungus Aspergillus niger, with corn

starch/corn syrup as the primary substrate that is acted on by the fungus.

The use of large scale fungal fermentations to produce citric acid dates from

about 1920, and the pharmaceutical company Pfizer was the major US citric

acid producer.

After the discovery of penicillin, produced by the related fungus Penicillium

notatum, in 1929, and the subsequent development of antibiotic therapies to

cure bacterial infections, the technology used to produce citric acid was

adapted to the large scale production of penicillin.

Mass production of penicillin was a major factor in saving lives during World

War II.

Fungi as food

Cheese Penicillium camembertii, Penicillium roquefortii

Rennet, chymosin produced by Rhizomucor miehei

and recombinant Aspergillus niger, Saccharomyces

cerevesiae

chymosin first GM enzyme approved for use in food

Fungi as food

Quorn mycoprotein, produced by Fusarium venenatum

High quality protein, very low fat

Soy fermentations, Aspergillus oryzaeRed yeast rice, Monascus purpureus

contains lovastatin?

Tempeh, made with Rhizopus oligosporus

Fungi as food

Fungi as food

Other fungal food products: vitamins and enzymes

• vitamins: riboflavin (vitamin B2), commercially produced by Asbya gossypii

• chocolate: cacao beans fermented before being made into chocolate with a

mixture of yeasts and filamentous fungi: Candida krusei, Geotrichum

candidum, Hansenula anomala, Pichia fermentans

• candy: invertase, commercially produced by Aspergillus niger, various

yeasts, enzyme splits disaccharide sucrose into glucose and fructose, used to

make candy with soft centers

• glucoamylase: Aspergillus niger, used in baking to increase fermentable

sugar, also a cause of “baker’s asthma”

• pectinases, proteases, glucanases for clarifying juices, beverages

Fungi as food

Perigord truffle, Tuber

melanosporum

Morels, Morchella

spp.

Agaricus bisporus

Lentinula edodes

Boletus edulis

Cantharellus

formosus

Tricholoma

magnavelare

Fungi as food

Cyttaria darwinii,

pan de indio, llao

llao, on

Nothofagus

dombeyi

Corn smut, Ustilago

maydis, cuitlacoche,

huitlacoche

Fungi as pharmaceuticals

Penicillin, from Penicillium notatum and other species

Discovered in 1928 by Alexander Fleming

Interferes with bacterial cell wall synthesis, -lactam antibiotic

Most widely used antibiotic to treat bacterial infections

Methods developed for mass production of citric acid used

Another -lactam antibiotic is cephalosporin, first isolated from Cephalosporium

acremonium

Various modifications of the cephalosporin molecule have resulted in a large

number of cephalosporin antibiotics having different action spectra and properties

Fungi as pharmaceuticals

Cyclosporin, from Tolypocladium inflatum, asexual state (anamorph) of

Cordyceps subsessilis, an insect parasite

First investigated for its antifungal properties, it was found to have strong

immunosupressive activity. First non steroid immunosuppressant, now used

in organ and bone marrow transplant therapy.

Selectively inhibits T-lymphocytes

T. inflatumC. subsessilis

Fungi as pharmaceuticals

Antifungal antibiotics

Griseofulvin, from Penicillium griseofulvum, used to treat cutaneous fungal

infections in humans, pets and livestock. Inhibits fungal mitosis, not used

much since development of triazole anti mycotics

Cilofungin, from Aspergillus nidulans, inhibits fungal cell wall synthesis

Fungi as pharmaceuticals

Statins, cholesterol lowering drugs, used for treating coronary heart disease

Inhibit the enzyme -hydroxy, -methylglutaryl-CoA-reductase, a key enzyme

in the cholesterol synthesis pathway, HMG to mevalonic acid

Japanese researchers first looked for HMG-CoA inhibitors in microbes,

discovered Mevastatin, from Penicillium citrinum

Lovostatin, patented by Merck in 1987, isolated from Aspergillus terreus,

more active than Mevastatin

Now various synthetic statins are made, based on the structures of the fungal

molecules

Fungi as pharmaceuticalsErgotamine

Consumption of grain contaminated with the sclerotia of Claviceps purpurea,

ergot, during the middle ages caused various human maladies. One

physiological effect of the ergot alkaloids present in the sclerotia is

vasoconstriction, and loss of blood circulation to the extremities could result in

loss of limbs to gangrene, depicted in the painting of “the beggars” by Pieter

Brueghel.

Ergotamine, one of the ergot alkaloids, has been used since 1920 to treat

migraine and cluster headache, interacts nonselectively with several

neurotransmitter receptors. Ergot derivatives are under investigation for

treatment of Parkinson’s disease.

Fungi as pharmaceuticals

Beano, - galactosidase, another useful metabolite from Aspergillus terreus

Fungi in human and animal health

Fungal pathogens, mycotic infections

Cutaneous mycoses, dermatophytes: Malassezia fufur, cause of dandruff,

tinea, ringworm caused by various keratinophilic fungi

Candidiasis: Candida albicans

Systemic mycoses, can be lethal

Histoplasmosis: Histoplasma capsulatum

Coccidiomycosis: Coccidiodes immitis

Cryptococcosis: Cryptococcus neoformans

Aspergillosis: Aspergillus fumigatus and other species

Pneumocystis pneumonia: Pneumocystis jirovecii, a major cause of AIDS

related mortality

Fungi in human and animal health

Mycotoxins in food

•aflatoxin: cause of turkey x disease, liver cancer, hepatitis, Reyes

syndrome, Aspergillus flavus

•ochratoxin: kidney disease, Aspergillus ochraceous, Penicillium verrucosum

•fumonisins: cause of esophageal cancer, equine leucoencephalomalacia,

Fusarium verticilloides

•zearalenones: swine estrogenic syndrome, Fusarium zeae

•trichothecenes: alimentary toxic aleukia, various fungus species

•patulin: carcinogen, Penicillium, Aspergillus, Byssochlamys species,

•ergot alkaloids: cause of “St. Anthony’s fire”, from infected rye

Fungi in human and animal health

Mushroom poisoning

Chlorophyllum molybdites may

be mistaken for edible

Macrolepiota or Agaricus spp.

Amanita phalloides is responsible for

several deaths every year, often in Asian

immigrants who mistake this species for

an edible Asian Volvariella spp.

Fungi in human and animal health

Inocybe geophyllum

Amanita pantherinaAmanita muscaria

Mushroom poisoning

Instances of dogs or young children experimentally ingesting

poisonous mushrooms are pretty common. Usually the

results are not fatal if treated quickly. The mushroom

species involved can be varied, but the most common and

attractive poisonous species are Amanita pantherina and A.

muscaria. These species are commonly implicated in

mushroom poisoning.

Fungi in industrial processes

“Stone washed denim” actually treated with

cellulase from Trichoderma reesei to give the

appearance of having been beaten by hand on

stones by the river.

Laundry detergents

contain fungal

enzymes,

proteases and

lipases, to remove

stains

Xylanase, phytase,

-glucanase added

to animal feeds to

improve nutritional

quality

pullulan: exocellular glucan from Aureobasidium pullulans

an edible film used as a base for

breath fresheners

also used as a drug delivery agent and

in the manufacture of Kevlar

Fungi in agriculture and forestry

Mycorrhizal fungi are symbiotic with most plants,

aid nutrient uptake

Arbuscular mycorrhiza

Ectomycorrhiza

Plant pathogens: the

majority of plant disease

agents are fungi

Fungi in agriculture and forestry

Storage rot and deterioration,

~40% of food lost due to

deterioration

Fungi in agriculture and forestry

Biocontrol agents

Plant and insect pathogens are used as mycoherbicides, mycoinsecticides

Commercial preparations of Colletotrichum

gloeosporioides, Fusarium oxysporum,

Sclerotinia sclerotiorum are sold as biocontrol

agents for control of various weeds.

Controversy about US program for use of F.

oxysporum on coca in Columbia.

Phragmidium violaceum, rust fungus used to control

invasive blackberry, now introduced in N. America

and is a concern to caneberry growers in Oregon.

Fungi in agriculture and forestry

Biocontrol agents

Several insect pathogenic fungi

are used as biocontrol agents to

control insect pests.

Entomophaga maimaga to

control gypsy moth, Metarrizium

anisopleae to control various

insects

Species of Trichoderma and other

fungi are being tried as biocontrols

against agricultural plant pathogens

Fungi in agriculture and forestry

Anaerobic chytrid fungi in rumen are essential for digestion

Fungi in traditional cultures

Phellinus igniarius powder used as a

tobacco additive for its stimulant

properties by Inuit people

Fungi in traditional cultures

Fomitopsis officianalis, “quinine conk”, a

conifer heart rot fungus that produces a very

large (1 m +) basidiocarp. The basidiocarps

“ghost bread” were used to carve special

grave guardians for the graves of shamans of

the native Americans of the coastal

northwest.

F. officianalis also reportedly used by the

ancient Greeks as a cure for tuberculosis.

and is still used in various herbal remedies.

Fungi in traditional cultures

Haida carving depicting the

story of the origin of

humans. “Fungus man”

guided Raven to collect

genitalia for the first people.

Haploporus odorus, a highly fragrant

polypore, used to decorate sacred

objects of the northern Plains

Indians

Fungi in traditional cultures

Fungi in traditional cultures

Fungi in traditional Asian medicine

Cordyceps sinensis

Parasitized caterpillars are

collected and sold for

general health benefits

Ganoderma lucidum, a wood

decomposing basidiomycete, used

to produce reishi, the herb of

longevity, reputed to have a variety

of beneficial health effects,

including anti tumor activity, anti-

HIV, blood pressure lowering, and

immune response suppression.

Fungi in traditional Asian medicine

Fungi in traditional cultures

Fungi in traditional cultures

Kombucha, Russian tea mushroom

Kombucha tea is reputed to have various healing properties. Produced by

fermentaion of sweetened black tea. Traditionally made in Russia, China and

Japan. The exact nature of its chemical constituents and their health benefits

are disputed.

“Kombucha mushroom” is actually a microbial cocktail of Acetobacter spp. and

several yeasts, Schizosaccharomyces pombe, Torulospora delbruckii,

Saccharomycodes ludwigii, probably many local variants with different yeast

species).

Teonanáctl

Halluncinogenic mushrooms mainly in the genus Psilocybe used by the

Mazatecs of Mexico and Guatemala to induce sacred visions, active

molecule psilocybin.

Fungi in traditional cultures

Hallucinogens, “entheogens”

Fungi in traditional cultures

Hallucinogens, “entheogens”

Tea made from A. muscaria used to induce visions by native people of

Siberia. Ibotenic acid, the active molecule is passed in the urine and

reportedly the experience was shared by consuming urine of the shaman or

others who consumed the mushroom tea.

Much undocumented speculation concerns

the relationship of A. muscaria to various

religions, including Christianity.

Fungi in biology

Classical genetic model systems

Neurospora, Schizophyllum: mating systems in fungi

Fungal model organisms, genomics “simple eukaryote systems”:

Saccharomyces, Neurospora, Aspergillus, Phanerochaete,

Magnaporthe, Ustilago, Trichoderma, Nectria

Fungal systems for transformation and heterologous gene expression:

Saccharomyces, Aspergillus

Fungi in biology

Neurospora crassa, a fungal model organism

G. W. Beadle and E.L. Tatum one gene-one enzyme hypothesis from

auxotrophic mutants, showed they were single gene mutations.

Later used to elucidate genes regulating mating in fungi

Ascospores in “ordered tetrads” that mirror the orientations of four chromatids

in meiosis, allows inference of recombination events

Fungi in biology

Fungal biodiversity

The fungi are a kingdom of eukaryotic life equivalent to plants and

animals

Global estimates of fungal diversity suggest there may be as many

as 1.5 million species of fungi (or more, > 3 M)

Only about 70,000 species of fungi currently are known, so less

than 5% of the total biodiversity of fungi is known

Fungi in ecological processes

•Fungal biomass global estimate: 15 Gt

•Carbon cycling: decomposition of woody

substrates

•Mycorrhizae: the interface between plants

and soil, links between plants in common

networks

•Plant pathogens: affect plant species

distribution, community composition

•Lichens: N2 fixation, primary productivity in

extreme environments, animal forage

•Insect interactions: various mutualisms,

pathogens and parasites

•Soil microbial community: >90% of

biomass is fungal

•“linking” organisms

Earth is a moldy planet!!!