The Wonderful Kingdom of Fungi
But, what exactly are fungi?
Last updated
But, what exactly are fungi?
Last updated
Fungi are living organisms that are neither plants nor animals. They are eukaryotic organisms, meaning their cells have a defined nucleus, like those of humans, plants, and animals. However, they differ from these other living beings in many ways:
They do not perform photosynthesis: Unlike plants, fungi cannot produce their own food from sunlight because they lack chlorophyll. Instead, they obtain nutrients by breaking down dead or decaying organic matter, such as fallen leaves, tree trunks, or organic waste. This is why they are considered natural recyclers, helping to maintain ecological balance by closing nutrient cycles and returning nutrients to the soil, where they can be used by other organisms.
Heterotrophic: Like animals, fungi get their energy from other organisms. However, instead of consuming food as we do, they absorb it from the external environment through their thread-like structures called mycelium.
Reproduction: Fungi can reproduce either sexually (meiosis) or asexually (mitosis) without forming a fruiting body.
There are approximately 144,000 known species of fungi, and the incredible diversity of life forms and morphological structures they present makes the Fungi Kingdom a group bursting with spectacular biodiversity.
Mycology, the science that studies fungi, has discovered only about 5% of all fungi, and it is estimated that there are still one and a half million fungi species yet to be discovered.
Fungi’s preferred source of nutrition is carbohydrates, although they obtain nitrogen by breaking down proteins.
Since their appearance on Earth, organisms in the Fungi Kingdom have developed numerous and diverse characteristics that allow them to adapt to some of the most unusual and surprising environments in nature.
Fungi have a unique structure that enables them to break down organic matter and grow in a wide variety of environments.
Fruiting Body: This is the visible part of the fungus, like the mushrooms we find on the ground. It is the structure responsible for producing and releasing spores for reproduction.
Mycelium: Most of a fungus is not visible, as it is beneath the soil or within the substrate. The mycelium is a network of fine threads called hyphae that extend through the environment in search of nutrients. The hyphae break down organic matter, such as leaves, wood, or food waste, and absorb the nutrients.
Spores: Fungi reproduce through spores, microscopic structures that are released into the environment. These spores can travel through air or water and, when they land in a suitable place, germinate and form a new mycelium, starting a new life cycle.
Chitin Wall: Their cell wall is extremely resilient due to chitin, a component that helps prevent desiccation and protects them from environmental challenges.
The Fungi Kingdom is divided into five major groups or phyla (divisions), each with unique characteristics and different types of organisms. Each group shares a common ancestor. Here are the five main groups:
Characteristics: This is one of the most primitive groups in the Fungi Kingdom. Chytrids are unique because many of their species have motile spores with flagella, which allows them to swim in water wow!
Habitat: They live in aquatic or very moist environments.
Importance: Some chytrids are decomposers, while others are parasites. An important example is Batrachochytrium dendrobatidis, a fungus that has caused significant declines in amphibian populations worldwide.
Characteristics: Zygomycetes are known for forming structures called zygospores during sexual reproduction. They have non-septate hyphae (meaning without compartments) and reproduce both sexually and asexually.
Common Examples: Black bread mold (Rhizopus stolonifer) is one of the best-known examples of this group.
Importance: Some zygomycetes are important decomposers, while others are pathogens in animals or plants.
Characteristics: This group is primarily composed of fungi that form symbiotic associations known as arbuscular mycorrhizae with plant roots. In this relationship, the fungus helps the plant absorb nutrients, especially phosphorus, and in return, it receives carbohydrates from the plant.
Habitat: They are primarily found in soil.
Importance: Arbuscular mycorrhizae are crucial for the health and growth of most plants. This type of symbiosis has existed for hundreds of millions of years and is fundamental to the success of many plant species.
Characteristics: This is the largest group of fungi and is characterized by producing spores in sac-like structures called asci. Inside the ascus, sexual spores known as ascospores are formed. Ascomycetes exhibit a great diversity of forms and life habits.
Common Examples: This group includes fungi like yeasts, truffles, the mold Penicillium (from which penicillin is derived), and other species like Claviceps purpurea, the fungus that causes ergot in cereals such as rye.
Importance: Besides their value in medicine and the food industry (bread, beer, wine), ascomycetes also include decomposer fungi and symbionts, as seen in lichens.
Characteristics: This group includes many fungi that produce mushrooms. Their spores are produced in a structure called a basidium, and they often form visible fruiting bodies, such as mushrooms, bracket fungi, and wood ears. Basidiomycetes also include fungi that form mycorrhizae.
Common Examples: Edible mushrooms like Agaricus bisporus, poisonous mushrooms like Amanita, and others like rusts and smuts, which are plant pathogens.
Importance: Basidiomycetes are key decomposers in forest ecosystems, helping to recycle nutrients. They also include edible and medicinal species, as well as plant pathogens.
Saprophytic Fungi (or Saprobes):
Feeding Method: Saprophytic fungi feed on dead or decaying organic matter, such as fallen leaves, tree trunks, plant and animal remains, or organic waste. They are the primary decomposers in ecosystems, breaking down dead matter and returning nutrients to the soil.
Common Examples:
Oyster mushrooms (Pleurotus ostreatus): These decompose wood and other waste like coffee grounds.
Bread mold (Rhizopus stolonifer): A saprophytic fungus that grows on decaying food.
Importance: They are essential for nutrient recycling in ecosystems and play a key role in the decomposition of organic matter, closing the cycle of life.
Parasitic Fungi:
Feeding Method: Parasitic fungi obtain nutrients from other living organisms, whether plants, animals, or even other fungi. They feed at the expense of their host, causing damage that can range from mild to fatal. They can infect both living and dead tissues.
Common Examples:
Ergot fungus (Claviceps purpurea): A parasite of cereals like rye.
Wheat rust (Puccinia graminis): A parasitic fungus that attacks wheat crops.
Candida albicans: A fungus that can cause infections in humans.
Importance: Many parasitic fungi are pathogens of plants and animals, including humans. They can cause serious diseases, but are also useful in certain contexts, such as in medical research.
Symbiotic Fungi:
Feeding Method: Symbiotic fungi form mutually beneficial relationships with other organisms. In exchange for nutrients, they provide benefits to the organism they associate with. The most common example is mycorrhizae, where the fungus partners with plant roots.
Common Examples:
Mycorrhizae: Fungi that associate with plant roots to improve water and nutrient absorption (especially phosphorus), while plants provide them with carbohydrates. This type of symbiosis is vital for most plants.
Lichens: A symbiotic association between a fungus and an alga or cyanobacterium. The fungus provides protection and support, while the alga performs photosynthesis, producing nutrients for both organisms.
Importance: Symbiotic fungi, especially mycorrhizae, are essential for ecosystem health. They help plants grow better, even in poor soils, and are key to sustainable agriculture.
a) To produce beverages like wine and beer b) To make foods like cheese and bread c) To consume directly d) For medicine e) All of the above
