Mushroom

Examples of mushrooms

Cordyceps

Shiitake Mushrooms

Oyster Mushrooms

Psilocybin

Amanita species (Fly Agaric)

Penicillium (expansum)

What are fungi, characteristics.

A diverse group of organisms

Some are unicellular, others are multicellular

Most are microscopic but some can be macroscopic

Structure of a fungal cell

Cell wall

Nucleus

Presence of membrane-bound organelles such as mitochondria and vacuole

Material of the cell wall in fungi

Chitin/polysaccharides

Nucleus characteristics in fungi

Enclosed by nuclear membrane

What do we call macroscopic fungi that produces FRUITING BODIES?

Mushrooms

Parts of a MATURE FRUITING BODY

Caps, gills, stalk and mycelium (network of hyphae)

Function of cap

Houses the spore-producing surface of the fruiting body, which consists of the gills.

Function of gills, and its location

Found on the underside of the mushroom cap and produces spores

Stalk function

Supports the cap

Benefits of a long stalk

The evolutionary benefit of a stalk is generally considered to be in mediating spore dispersal. An elevated mushroom will more easily release its spores into wind currents or onto passing animals.

What is a hyphae strain?

Hyphae that are genetically different

Hyphae structure

Long, branching filaments.

How do hyphae grow? (below the soil)

Grows from a tip and branches out in search of more food sources, and form a network called mycelium

How do humans get nutrition?

Uses heterotrophic nutrition by using complex organic compounds as a source of carbon

Ingestion → digestion

How do fungi feed?

Through saprotrophic nutrition, the fungi secrete enzymes through the hyphae onto nutritional substrate to break down the complex organic matter into simpler molecules, and absorb it as nutrients.

allows fungi to decompose organic matter and cycle nutrients in their environment.

What example of fungi reproduces asexually? What is their method of reproduction?

Yeast, budding

Stages of budding (also what is left after budding?) What is the newly formed cell called?

Bud formation → Mitosis → Nucleus migration

Birth scar and bud scar

Daughter cell

How do mushrooms reproduce sexually?

Through spore formation

Stages of a mushroom

Spore release → inoculation → germination → mycelial expansion → hyphal knot → primordia formation → fruitbody selection → mature fruitbody

During spore release, what happens?

Plus and minus spores are released from the gills

How many spores are produced by the mushroom cap? How far can they travel?

Hundreds of thousands of spores are produced by a mushroom that can travel beyond the limits of the parent mushroom. They can travel some distance due to the wind or animals before landing.

When does the life cycle of a mushroom start?

During spore release

What can a spore germinate into?

A spore (+ or -) will germinate into a hyphae strain of its mating type.

What happens during germination?

Spores can germinate to produce its hyphae.

Why do mushrooms need to release many spores?

Most spores simply die where they land, as it lacks food and water

Structure of a mycelium, and what does it do for the fungi?

Web-like root system

Hold the mushroom firmly to the ground (remains rooted to the ground, which can branch out.)

Absorbs water and nutrients for the mushroom

What happens during mycelial expansion?

Two different strains of hyphae (+ and -) meet and combine to start forming mycelium

What is a hyphal knot?

It is the first point at which the pinhead and body of the mushroom begin to sprout.

Will all pinheads grow?

No, as most of them will stop growing. So it is easier to pinpoint the healthy pins that will eventually grow into full-grown mushrooms.

What is a pinhead?

Knot of hyphae - starting point of the ‘baby mushroom’

Primordia to mature mushroom. What happens in that stage?

The primordium develops into a mature mushroom

Steps to cultivating mushrooms

Compost preparation

Mushroom growth

Harvest

phases of compost preperation

• breakdown of organic material

• conditioning

How can we prepare compost (substrate in which the mycelium grows)

Materials like millets, rolled oats, sawdust, straws, vermiculite and brown rice flour are usually utilised for the compost. An autoclave is used to sterilise the substrate to eliminate insects, and other harmful microbes like fungi and bacteria.

What do mushrooms like other multicellular organisms, need?

They require carbohydrates, nitrogen, elements, vitamins, fats and lipids.

CENVFL

So what must be prepared in the compost? Why?

There must be an adequate supply of these essential ingredients to complete the composting process, as mushrooms obtain their nutrients and water from the compost substrate. During composting, carbon and nitrogen are released into the substrate.

Phases of mushroom growth

• Spawning

• Casing

• Pinning

What happens during the phase of mushroom growth?

Mushrooms grow and multiply, generating heat as they consume food and water. As long as water, oxygen and food are available, they continue developing to a maximum population at the highest temperature they can tolerate.

What does the spawn in spawning mean?

A mass of mycelium that has been cultivated specifically for the purpose of being transferred to another substrate. This expands the amount of mycelium you have for fruiting in the future.

How do you achieve spawning?

The spawn is achieved by inoculating it into the compost substrate with mycelium from the stock culture. The mushroom mycelium will start to grow out, running across and devouring the grain, eventually taking over the whole jar (colonising substrate).

What do we do with the spawn?

This is then used to inoculate numerous other sterilised grain jars, exponentially increasing the volume of available spawn.

One jar can typically be used to spawn ten more jars of similar size.

What happens during casing? (growing of the mushroom)

The grain spawn is transferred to other fruiting substrate used to grow mushrooms

Though the type of substrate used is dependent on the species of mushroom you are growing which may include straw, wood chips or compost.

What happens during casing? (what happens to the mushroom)

Once the substrate is inoculated, the mushroom mycelium will continue running, consuming nutrients and engulfing the substrate. Once the entire substrate is engulfed in the mycelium, you can attempt to induce pinning.

How can we induce pinning?

By changing the abiotic factors in the environment (such as temperature and humidity) to induce pinning (small mushroom formation)

If mushrooms pins are given the right conditions, what happens?

Many of those mushroom pins, if given the right conditions, will continue to grow, drawing up water and nutrients from the substrate and rapidly turning into full-sized mushrooms.

Phases of harvesting

• Cropping

Now what happens during cropping

Mushrooms are harvested at their peak maturity. They are typically twisted or cut off at the base to avoid damaging the mycelium, which can continue producing new flushes of mushrooms.

How can we continue harvesting numerous mushrooms from a single mycelium?

If a proper environment is maintained, a healthy and productive substrate can produce numerous “flushes” of mushrooms, allowing the cultivator to harvest the mushrooms 2 or 3 times.

What are the requirements for mushroom growth?

Composting material must release

• carbon and nitrogen

Moisture

• Needs to be constantly replenished

• Too much moisture leads to mould growth

Temperature

• Varies according to the species grown

Others

• Need adequate air exchange (aeration)

• Must be sterile, as foreign organisms can kill the mushroom

Factors that affects germination of spores

Temperature

Moisture

Nutrients

aeration

Main factors that affect mycelium pinning

Aeration

Humidity/Moisture

Temperature

Nutrients

What causes the formation of the fruiting body?

Triggered by a change in abiotic conditions that signal conditions are either no longer ideal for survival or are now suitable for safely producing the fruiting body.

• A drop in nutrients: Signals to the mycelium that its food source is depleting, prompting it to reproduce before resources are gone.

• Fresh air: Increased oxygen and decreased carbon dioxide indicate that the mycelium is near the surface, making it a safe place to grow mushrooms

• Light exposure: Tells the mycelium it is no longer buried and can safely produce mushrooms

• Temperature drop → Too low/high a temperature may kill them, prompting them to reproduce before they die.

• High humidity: Moist conditions support the growth and health of developing mushrooms, signalling that it is suitable to produce mushrooms

Where are yeasts found in?

Found worldwide in soils, and on plant surfaces and are especially abundant in sugary media such as flower nectar and fruits. The fungus is widely used in the production of bread and alcohol

Are some yeasts dangerous?

Some yeasts are mild to dangerous pathogens of humans and other animals.

CANDIDA ALBICANS → its harmful effects

Overgrows and causes the infection, candidiasis. There are several types of Candida: Oropharyngeal (mouth and throat), genital or diaper rash.

Cordyceps → beneficial uses

CORDYCEPS (‘caterpillar fungus’)

• Improve lung capacity, increases energy

Shiitake mushrooms → beneficial uses

Shiitake mushrooms (‘fragrant mushroom’)

• Improves cardiovascular health

Oyster mushroom benefits

Oyster mushroom (‘carnivorous fungus’)

• Supports metabolic health

Harmful effects of Psilocybin

Psilocybin ("magic mushrooms")

• cause anxiety, paranoia, nervousness and may lead to psychosis

Harmful effects of Amanita

• poisonous when consumed, affecting liver and kidney

Penicillium - harmful effects

Penicillium (Penicillium expansum)

• produces mycotoxin (releases patulin)

• Found in rotting/mouldy fruits, grains and foods.

• Causes nausea, gastrointestinal disturbances and vomiting

• Spoilage of fruits

Benefits of growing a mushroom

High yields in small spaces

quick growth cycle

Low environmental impact

Water usage

elaborate High yields in small spaces

Mushrooms are grown year-round and do not require much land. Mushrooms produce high yields from a very small physical footprint

Quick growth cycle, elaborate

Mushrooms grow really quickly, and this allows farmers to have multiple yields in a year.

Low environmental impact, elaborate

CO2 emissions of Mushrooms are lower than that of other produces.

Water usage, elaborate

Consumes less water to grow compared to other produce.

What happens during the formation of a “hyphal knot”?

Individual strands of hyphae bundle together and prepare for the first stage of a mature mushroom formation, the fruiting body. This leads to the formation of a pinhead on the surface of the mushroom