BESC 204 - Exam 3

Explain the primary ecological role of fungi

recyclers/degraders, break down complex organic compounds into simple molecules, minerals, and energy, elements are then reused by other organisms

List the structural components of plants that fungi can degrade

Cellulose

Lignin

Pectin

Cutin

Nutritional succession

zygomycetes > simple sugars

ascomycetes > cellulose

basidiomycetes > cellulose and lignin

R-selected

Species that reproduce early in their life span and produce large numbers of usually small and short-lived offspring in a short period.

K-selected

organisms that reproduce later in life, produce fewer offspring, and devote significant time and energy to the nurturing of their offspring.

Spore dispersal mechanisms utilized by fungi

Wind

Water

Vector

Self-propelled

Spore dispersal mechanism of Pilobolus sp.

-Aerial growth directed towards a light source

-black spore mass at head of sporangium is ejected 3 meters after rupture of subsporangial vesicle

-Parasitic nematode larvae crawl up the sporangium and are launched with the spores

Spore discharge utilized by Basidiomycetes.

-thin layer of water coats the spore

-droplet of water begins to swell at the base of the conidium due to excretion of sugar molecules

-once swollen, droplet grows large enough to contact the spore

-droplet rapidly redistributes, flowing into the thin coat of water

-redistribution shifts the center of gravity causing it to catapult away

Buller's Drop

The droplet of water that accumulates at the tip of the basidiospore

fermentation reaction

glucose----> 1- ATP

----> VFA's + CO2 + CH4

Why can't a beverage be produced from fermentation alone?

To get anything above 18%, the beverage must be distilled

Ingredients found in true beer

Yeast

Hops

Malt

Water

Difference between an ale and a lager

Ale - complex flavor; brewed at a warmer temperature (55); quicker

Lager - cleaner taste; brewed at a cooler temperature (45); takes more time

Saccharification

Application of heat to a starch to trigger the enzymatic processes of converting the starch to fermentable sugar.

Differences between wine making and beer making

1) Ingredients for beer are sterilized; those for wine are not

2) Different species or strains of yeast used

3) Sugar for beer comes from malt and must be converted; that for wine comes from grape juice

4)Additives - hops added to beer; none to wine

5) Water added to beer; none to wine

Effect of prohibition on US brewing industry

Caused a sharp decline

Pasteur's role in zymurgy

-Discovered that yeast was responsible for the fermentation process

-Showed that hops acted to inhibit bacterial growth

-Discovered bacteria in fermenting beer > Pasteurization

noble rot

Botrytis - causes healthy grapes to shrivel and adds its own character to the wines. This requires a period of damp misty mornings and warm afternoons.

Ice Wine

Grapes are harvested and pressed while frozen solid (-10°C) so water can be driven out as shards of ice - leaving a higher concentration of sugars - and after

fermentation - higher concentration

of alcohol.

Sake

Rice + Aspergillus oryzae turns starch to sugar

Sugar + yeast makes the brew

Camembert

a soft surface-ripened cheese with a thin grayish-white rind and a yellow interior

p. camemberti

blue cheese

Made from sheep's milk; aereated and left out

P. roqueforti

Quorn

Meat substitute made from fungal protein that is fermented and mixed with egg whites and vegetable oils.

Soy Sauce

soybeans crushed

formed into cakes and placed in cool, dark environment for 3 months

fungi grow on cakes

cakes soaked in salt water for 1-3 years

flavored salt water = soy sauce!

soybeans + wheat + Aspergillus oryzae

Tempeh/Oncom

cooked soybeans + Rhizopus oligosporus

-made from legumes

soybeans + neurospora

-only human food made with Neurospora

Ecovative design

Pleurotos ostreatus

packing material and house insulation

Mycoworks

Make handbags out of leather like (mycellium/reishi) products

Innomy

Make meat alternative using field mushrooms

Meati

Make meat alternatives out of mycellium

Common measures to avoid mushroom poisonings

1) Dig, don't pick

2) Look for or do a spore print

3) Keep different specimens separate

4) Don't eat wild mushrooms raw

5) Don't consume with alcohol until you know the mushroom

6) Learn Latin names

7) Get a good identification manual

Pileus

A

Gills

D

Annulus

B

Scales

Arrows

Stipe

E

Volva

C

steps for commercial mushroom production

1) Growing the spawn

2) Compost

3) Spawning - adding grain infested with mycelium to compost

4) Casing - cover compost with low nutrient medium

5) Growth - 2 to 3 weeks

6) Harvesting

Fool Proof Four

Morels

Shaggymane

Giant puffballs

Sulfur shelf

pink button meadow mushroom

Agaricus campestris

white button mushroom

Agaricus bisporus

morel

Morchella species

Giant puffball

Calvatia gigantea

Common bolete

Boletus edulis

Shiitake

Lentinula edodes

Huitlacoche

Ustilago maydis

Why are dogs and pigs used to hunt wild truffles?

They can smell the scent of the truffles which are similar to animal pheromones

Death Cap

Amanita phalloides

Looks like Amanita caesarea

False Morel

Gyromitra esculenta

Looks like

Inky cap

Coprinus atramentarius

Coprine

-causes hot flushes, metallic taste, tingling, numbness, headache, nausea, vomiting

-occurs when consumed with alcohol

-Species of Coprinus atramentarius (Inky caps)

Gyromitrin

-cause bloating, nausea, vomiting, diarrhea, dizziness

-liver toxicity after 36-48 hours

-Species of Gyromitra

Miscellaneous Gastrointestinal irritants

-causes vomiting and diarrhea, with abdominal cramps

-full recovery after about a day

-common to multiple fungi

Orellanine

-causes nausea, vomiting, and loss of appetite 12 hours - 3 days after consumption

-causes renal damage occurs after 3-15 days

-species of cortinarius

Amatoxins

-attack liver, intestines, and kidneys

-experience diarrhea, vomiting, and abdominal pain

-false remission

-collapse of kidney and liver function followed often by death

Phallotoxins

lethal if injected

no effect if taken orally

Psilocybin

-natural hallucinogen found in certain mushrooms

-causes uncontrollable laughter, hallucinations, euphoria, and disembodied experience

-begin 10-30 minutes after consumption

-can cause bad trips

-species of Psilocybe, Panaeolus, Conocybe, and Gymnopilus

-in the LSD family

Why do poisonous mushrooms look like edible mushrooms?

Mimicry to protect them from predators; could just be happenstance

What kind of organisms can biocontrol fungi be used on?

-Insects

-Nematodes

-Other fungi

etc.

Advantages and Disadvantages of Fungal Biocontrols

Pro:

-Reduced use of chemical pesticides

-High reproductive capacity

-Short generation time

-Specific to a particular host

-Resting/resistant stages

Con:

-Only cause damage not death

-Only reduce a population, not eliminate

-Acts slowly

-Cause damage to other beneficial organism

-Limited to where and when it can be effective

Two modes of nematode trapping

Arthrobotrys dactyloides: hyphal cells swell around nematode

Hirsutella rhossilliensis: feeds off the nematode

Modes of action of Trichoderma

-Mycoparasitism: acts like a parasite to the parasite

-Antibiosis: secondary metabolites act like antibiotics

-Competition: compete with parasites

Uses of beneficial fungi for improving plant health

Endophytic:

-Promote plant growth, reduce salt, heat, or drought stress

-Improve resistance to insects

-Produce bioactive compounds

Mycorrhizal:

-Improve nutrient availability

-Improve systemic resistance

-Influence plant bioactive compound production

Pros and Cons of Genetic Modification

Pro:

-Increased yield, drought resistance, nutritional value

-Reduction of pesticide use

-Fungal degrading enzymes can reduce fungal infections

-Could be more environmentally friendly

-Reduced browning and longer shelf life

-Potential for pesticide, drug production

Con:

-Might not be effective against new pathogens or environments

-Traits can drift to non-GMO crops

-Resistance genes are only against one pathogen

-Pathogens can overcome resistance by mutation

Examples of genetically modified fungi

-Breeding new strains of mushroom using basidiospore chemical mutagenesis

-Genetic engineering by Agrobacterium

-Bt corn (Bacillus thuringiensis)

Why does CRISPR/Cas9 not require USDA approval and regulation?

In the non-browning mushrroms, no genes were removed nor was foreign DNA added

Genetically modified non-browning mushrooms

-CRISPR puts cuts in an enzyme family to stop production of that enzyme

-deletes some pairs in PPO which slows aging and browning of mushrooms

-USDA says it doesn't need approval

What changes does CRISPR/Cas9 make to DNA?

-CRISPR causes mutations; can edit DNA by taking out or inputting sections of genomic material

-Cas9: enzyme carries the guide RNA to the target nucleus

Methods of Genetic Modification

Agrobacterium

Mutagenesis

Gene gun

CRISPR

Brief history of Genetic Modification

-Breeding has been around for millenium

-Mendel experiments

-X-ray mutagenesis during the 20s

-Hybrid vigor during Green Revolution

-CRISPR in the 80s

Symbiosis

A close relationship between two species that benefits at least one of the species.

Mutualism

A relationship between two species in which both species benefit

Commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected

Parasitism

A relationship between two organisms of different species where one benefits and the other is harmed

Ectomycorrhizae

-A type of mycorrhizae in which the mycelium forms a dense sheath, or mantle, over the surface of the root. Hyphae extend from the mantle into the soil, greatly increasing the surface area for water and mineral absorption.

-Only affect trees

-Truffles, false morrels, amanita muscaria, chanterelles

VAM Endomycorhizzae

-Gain entry into host

-Zygomycota (Glomeromycota)

-Have broad host range (orchids)

What is the benefit to the plant and to the fungus having this relationship?

Plants:

-Increased surface area for nutrient and water uptake

-Selective acquisition of some nutrients

-Increased tolerance of poor soil conditions

-Protection from soil borne pathogens

Fungus:

-Food

Hartig Net

hyphal network, that extends into the root, penetrating between the epidermal and cortical cells of ectomycorrhizal plants. This network is a site of nutrient exchange between the fungus and the host plant.

Mantle

External sheath of mycelium around tree roots

arbuscle

Nutrient transport tissue associated with mycorrhizal fungi

Vesicle

A membrane bound sac that contains materials involved in transport of the cell.

Lichen morphological types

Foliose (leaf like)

Crustose (crust like)

Fructicose (shrub like)

Lichens

small plants that consist of algae (phycobiont) and fungi (mycobiont)

Lichen's role in the environment

-Break down rocky substrate to make it possible for plant habitation

-Indicators of air pollution

Lichen reproduction

asexually, sexually, or both

asexual - stress resistant packets of fungal and algal cells

sexual - fungus reproduces by producing an ascocarp (alga does not sexually reproduce in the lichen)

Benefit the algae gets from mycobiont

-Protect them from environment

-Act as an anchor

endophytic fungi

fungi that live within aboveground parts of plants without causing obvious deleterious symptoms

Advantages of endophytic relationship

Improve ability to tolerate abiotic stresses (drought) and improve resistance to insects and herbivores

Laboulbeniomycetes

-parasite found on ladybugs and other insects, passed by contact, spore producing structure

-Mild parasites, but the insects don't show any disease symptoms

-Bug STD

Septobasidium

-grows on woody plants

-looks like a velvety patch

- scale insect lives underneath it- beneficial

- symbiotic relationship (insect gets nutrients from tree, fungi gets nutrients from insect)

-Fungi protects insect, insect gets food from plant beneath

Neocallimastix

in intestines of herbivores and symbiotic since organisms can't make cellulase to break down cellulose it does so for nutrients. (cow example)

Leaf cutter ants and fungi

-Take leaf cuttings and feed them to fungus gardens, feed off hyphae (bromatia)

-Ants tend fungus

-Can be attacked by escovopsis, if left untended; inhibited by streptomyces on ants

Termitomyces

cultivated by termites

Leaf Cutter Ants vs. Termites

-Ants in New World; termites in Old World

-Termites have larger gardens

-Termites eat the plant material; ants give it to fungus

-Ant fungi is a ball; termite fungi are balls with conida and conidiphore clusters

-Termite mounds have fruiting structures, ant mounds do not

Cordyceps and Ophiocordyceps

-Fungi that are parasitic to insects and arachnids

-Infect them and cause them to act strange

-Insects die from fungal infection

-Used in China for medicinal purposes

-Vegetable Insects/Catepillars