7.5 Importance of Fungi

Fungi are important players in economic gains as well as losses.

• They decompose organic matter, recycling nutrients in ecosystems.
• They form symbiotic relationships with plants, aiding nutrient uptake.
• Fungi are sources of antibiotics, enzymes, and food (mushrooms, yeast).
• They also have vital roles in research, biotechnology, and as indicators of environmental health.
• Fungi cause diseases in humans, other animals and plants.
• They cause huge agricultural damage every year.

Importance of Yeast

• Yeast is renowned for its pivotal roles in baking and brewing due to its remarkable ability of producing ethyl alcohol and carbon dioxide from sugars such as glucose by fermentation, where it leaves dough and ferments sugars to create bread, beer, and wine.
• It also has great implications in genetic research, serving as a model organism for scientific exploration.
• Its simple yet elegant biology, genetic tractability, and resemblance to human genes have unlocked insights into fundamental biological processes.

• Yeast, particularly *Saccharomyces cerevisiae*, converts sugars from malted grains or other sources into alcohol and carbon dioxide.
• This fermentation gives rise to the diverse flavors, aromas, and alcohol content in beer and wine and also to making bread.

• In bread-making, yeast acts as a leavening agent.
• When yeast consumes sugars and produces carbon dioxide gas, it gets trapped within the dough, causing it to rise.
• This process results in the fluffy, airy texture of bread.
• Yeast's ability to produce gas is also crucial in other baked goods like pastries and cakes.

• Yeast, especially Saccharomyces cerevisiae, serves as a valuable model organism in genetic research.
• Its simple and well-characterized genome, along with its similarities to human genes, makes it an ideal subject for studying genetics, cell biology, and molecular processes like mutations, genetic recombination and laws of segregation.

Biotechnology: - Yeast is used in biotechnological processes to produce enzymes, biofuels, and pharmaceuticals.

Food Production: - Yeast is involved in the production of various food items, including cheese, yogurt, and soy sauce.

• Often the first choice eukaryotic organisms for protein production is the yeast (Saccharomyces cerevisiae).
• Yeast cells can take up foreign DNA and integrate into their genomes.
• Yeasts also have plasmids that can be used as gene vectors and some time yeasts are better than bacteria at synthesizing and secreting eukaryotic protein.
• Yeast is currently used to produce a number of proteins.
• In some cases the same product, for example interferons used in cancer research can be made in either yeast or bacteria.
• In other cases such as hepatitis B vaccine, yeast alone is used.

Science, Technology and Society Connections (from textbook): Discover how fungi act like nature's medicine cabinet, giving us antibiotics and valuable compounds.

Antibiotics Obtained from Fungi

MUTUALISM: Lichen and Mycorrhizae

Definition: Mutualism is the association in which both the partners get benefit. The two key mutualistic symbiotic associations formed by the fungi are lichens and mycorrhizae.

Lichens

• Lichens are an association between a fungus (mostly Ascomycotes and imperfect fungi and a few basidiomycetes), a cyanobacterium or green alga.
• The top layer, composed of resilient fungal hyphae, is thin.
• In the middle layer, fungal hyphae intertwine with photosynthetic cells.
• The bottom layer consists of loosely packed fungal hyphae that facilitate nutrient transfer within the fungus.
• Traditionally, lichens were thought to have mutualistic relationships, with the fungus gaining nutrients from the algal cells and the algae receiving protection from drying out.
• However, recent research suggests that lichen associations may involve a controlled form of parasitism by the fungus on the algae cells.

Mycorrhizae

• Mycorrhizae represent mutually beneficial partnerships between soil fungi and the roots of the majority of plants.
• This association occurs in 95% of all families of higher plants.
• Fungal hyphae play an important role by increasing soil contact and surface area, aiding in the direct uptake of essential nutrients like phosphorus, zinc, and copper from the soil into the roots.
• Plants hosting mycorrhizae tend to grow successfully more than those without these partnerships.
• Mycorrhizae come in two primary types, each with unique characteristics:
• Endomycorrhizae: These fungi penetrate plant roots, specifically the outer cells, forming coils, swellings, and tiny branches while also extending into the surrounding soil.
• Ectomycorrhizae: These fungi create a protective layer outside the root, growing between cell walls. They are typically associated with trees like pines and firs.

Edible Fungi

• In the Orient, *Aspergillus tamarii and other imperfect fungi are used in the orient to produce soy sauce* by fermenting soybeans.
• Among basidiomycetes, there exist approximately 200 varieties of edible mushrooms, primarily Agaricus, alongside about 70 potentially poisonous ones often referred to as toadstools.
• Some edible mushrooms are cultivated for commercial purposes.
• Notably, *Morchella esculenta, resembling mushrooms, and truffles*, known for their subterranean fruiting bodies, belong to the Ascomycotes.
• Edible and poisonous mushrooms can look very much alike and may even belong to the same genus.
• There is no simple way to tell them apart; they must be identified by an expert.
• Some of the deadliest mushrooms fall under the *Amanita genus, aptly named "destroying angel" (Amanita virosa) and "death cap" (Amanita phalloides*).
• Consumption of a single mushroom from either species can be fatal, while certain mushrooms can induce intoxication and hallucinations when ingested.

Ecological Impact of Fungi

Fungi are ecological powerhouses, influencing nutrient cycling, plant health, soil formation, and even the balance of predator-prey interactions. Their role in ecosystems is intricate and multifaceted, highlighting their significance in maintaining the health and sustainability of the natural world.

• Decomposers and Nutrient Cycling: Fungi serve as nature's recyclers, breaking down dead organic matter, such as fallen leaves and wood, returning vital nutrients to the ecosystem. This decomposition process enriches soil and supports plant growth.
• Mycorrhizal Partnerships: Mycorrhizal fungi form mutually beneficial relationships with plants, enhancing nutrient uptake and contributing to overall ecosystem health.
• Predators and Soil Ecosystems: Predatory fungi regulate populations of microscopic organisms and compete with bacteria, shaping microbial communities in soils.
• Biotransformations and Pollutant Degradation: Fungi play a role in biotransformation of compounds in the environment, including pollutant degradation.
• Carbon Cycling and Humus Formation: Fungi liberate carbon dioxide during decomposition and contribute to humus formation, enriching soil structure and supporting diverse ecosystems.

Pathogenic Role of Fungi

Fungi are causative agents of many plant, animal and human diseases. A few are discussed below:

Role of Fungi in Plant Diseases

• Fungi can cause serious diseases in plants, including epidemic diseases that can destroy complete crops.
• These tiny organisms threaten all crops and trees.
• They create problems like leaf spots, wilting, and rotting.
• Some common plant diseases caused by ascomycotes are powdery mildew, chestnut blight, Dutch elm disease, apple scab and brown rot which attack cherries, peaches, plums and apricots.
• Diseases caused by basidiomycetes include smuts and rusts that attack a large variety of plants e.g., the cereal crops like wheat and corn.

Role of Fungi in Animal Diseases

• Fungal diseases in animals, including humans, are diverse and can range from mild skin infections to severe systemic illnesses.
• Some fungi cause superficial infections in which only the skin, hair or nails are infected.
• Ringworm (Microsporium audouni) and Athlete's foot (Tinea pedis) are examples of such diseases.
• Candidiasis is caused by Candida yeast and can produce infections in humans, such as oral thrush.
• In animals, it can lead to conditions like skin and ear infections.
• Other fungi cause systemic infections that infect internal tissues and organs and may spread through the body.
• Histoplasmosis is caused by inhaling spores of the Histoplasma fungus, is a serious infection of lungs.
• Aspergillosis caused by Aspergillus fumigatus is a respiratory fungal infection seen in birds, particularly parrots, and can also affect humans with weakened immune systems.
• Some strains of Aspergillus flavus produce aflatoxin, a cancer causing mycotoxins in improperly stored grains of peanut, corn etc.
• Ergotism is caused by purple ergot rye.
• It causes nervous spasm, convulsion, psychotic delusion and even gangrene.
• Pneumocystis Pneumonia (PCP) is caused by the fungus Pneumocystis jirovecii and mainly affects individuals with weakened immune systems, such as those with HIV/AIDS.

Summary Table of Diversity Among Fungi

Intermediate Level

Classification of Fungi in Detail

Zygomycota in Detail

Ascomycota in Detail

Basidiomycota in Detail

Deuteromycota in Detail

Importance of Fungi in Detail

Remember

• - Zygomycota = conjugating fungi.
• - **Ascomycota** = sac fungi.
• - Basidiomycota = club fungi.
• - Deuteromycota = imperfect fungi.
• - **Zygomycota** = zygospores.
• - Ascomycota = asci and ascospores.
• - Basidiomycota = basidia and basidiospores.
• - **Deuteromycota** = conidiospores.
• - Examples: Rhizopus, Penicillium, Agaricus, Aspergillus.
• - Importance: Decomposition, symbiosis, food, medicine, research, biotechnology, diseases.

Common Mistakes

• 1. Confusing the four groups of fungi – Zygomycota, Ascomycota, Basidiomycota, Deuteromycota.
• 2. Confusing zygospores and ascospores – Zygospores = Zygomycota; Ascospores = Ascomycota.
• 3. Confusing asci and basidia – Asci = Ascomycota; Basidia = Basidiomycota.
• 4. Thinking Deuteromycota have a sexual stage – Deuteromycota have no sexual stage.
• 5. Confusing the examples – Rhizopus (Zygomycota), Penicillium (Ascomycota), Agaricus (Basidiomycota), Aspergillus (Deuteromycota).
• 6. Thinking all fungi are harmful – Many fungi are beneficial.
• 7. Confusing lichens and mycorrhizae – Lichens = fungus + alga/cyanobacterium; Mycorrhizae = fungus + plant roots.
• 8. Thinking yeast is only used in baking – Yeast is also used in brewing, genetic research, biotechnology, and food production.
• 9. Forgetting the antibiotics obtained from fungi – Penicillin, Streptomycin, Tetracycline, Erythromycin, Fumigatin.
• 10. Confusing the pathogenic roles of fungi – Plant diseases, animal diseases, human diseases.
• 11. Thinking all mushrooms are edible – Some mushrooms are poisonous (e.g., Amanita virosa, Amanita phalloides).
• 12. Forgetting the ecological impact of fungi – Decomposers, mycorrhizal partnerships, predators, biotransformations, carbon cycling.

Quick Revision

• The kingdom fungi are a diverse group comprising of more than 100,000 known species, most of which are terrestrial.
• The ancestry of fungi that dated back to about 570 million years ago, has not been determined.
• They are thought to have evolved from red algae as they both lack flagella at any stage of their life cycles.
• Classification of Fungi: Fungi are classified into four main groups based primarily on the methods of reproduction and types of sexual reproductive structures. These groups also differ in the types of hyphae and some other structures.
• Zygomycota (Conjugating Fungi):
• Zygomycota, also known as conjugating fungi, are a group of typically fast-growing fungi that can be found in various habitats, including soil and decaying organic matter.
• Commonly they are saprotrophs on bakery goods, vegetables and fruits.
• They are known for their important role as decomposers, breaking down organic material in ecosystems.
• However, some Zygomycota members can be pathogenic to plants or animals.
• They have non-septate hyphae forming a well-developed and branching mycelium.
• Asexual reproduction takes place by sporangia containing conidia or spores e.g., in Rhizopus nigricans (Black bread mold).
• Sexual reproduction takes place by conjugation. Conjugation occurs only between a member of a plus (+) and a minus (-) strain. When hyphae (stolon) of opposite mating strains meet, hormones are produced that cause the tips of the hyphae to come together. This fusion results in formation of specialized gamete producing structures called gametangia. These structures become separated from rest of the mycelium by the formation of septa. A diploid zygote is thus formed by fusion of haploid nuclei from opposite strains. The zygote develops into a zygospore with a thick and resistant wall to bear unfavorable conditions. Zygospores germinate under favorable conditions and divide by meiosis. Hyphae emerge from zygospore breaking its wall. The tip of the hypha develops into a sporangium containing many nuclei. When mature, the wall of the sporangium ruptures, spores are liberated and then then spores grow into new strain of mycelium. Thus, the life cycle of Rhizopus is continued.
• Ascomycota (Sac Fungi):
• Ascomycota, commonly referred to as sac fungi, is one of the largest and most diverse phyla within the fungal kingdom.
• Ascomycota display remarkable diversity in terms of habitat and lifestyle. They can be found in various ecosystems, from soil and wood to symbiotic relationships with plants and lichens.
• Many economically important fungi belong to this group, including morel and truffle mushrooms, brewers' and bakers' yeast, and several plant pathogens.
• They are named after their characteristic reproductive structures, known as asci (singular: ascus), which are sac-like cells containing sexually produced spores.
• Their hyphae usually have septa, but the cross walls are perforated so that cytoplasm can move from one compartment to the other.
• Ascomycetes reproduce both asexually and sexually.
• Asexual reproduction involves production of spores called conidia (singular conidium) or conidiospores (Greek: konis, dust and spora, seed). Conidia vary in shape, size and maybe multicellular. There are no sporangia in Ascomycetes. The conidia develop directly on the tips of modified ariel hyphae called conidiophores. When released conidia are blown away by wind. Conidia occur in various shapes, sizes and colors in different species. The color of conidia is what gives the characteristic brown, blue, pink or other tint to many of these molds.
• In unicellular yeasts, asexual reproduction takes place by budding. In this process a small projection (bud) grows and eventually separates from the parent cell. Each bud can grow into a new yeast cell. Yeast also reproduces asexually by fission.
• Sexual reproduction takes place after two hyphae grow together and their cytoplasm blend. The nuclei from parent hyphae pair in this cytoplasm but do not fuse. New dikaryotic hyphae develop from the fused structure. The n + n hyphae form a fruiting body known as ascocarp. It is a reproductive structure where spores are produced and released. Ascocarps vary greatly in shape, for instance cup shaped in cup fungi, flask shaped in molds while stalked and crown by shaped structures in morels. The asci develop in the ascocarp surrounded by sterile hyphae. Within an ascus, the two nuclei fuse and form a diploid zygote that undergoes meiosis to form four haploid nuclei. This process is usually followed by one mitotic division of each of the four nuclei, resulting in eight haploid nuclei. Each haploid nucleus develops into an ascospore. Thus, there are usually eight haploid ascospores within the ascus. In most ascomycetes the asci become swollen as they mature. The mature asci burst liberating the ascospores. If spores land in a suitable location, they germinate to form a new mycelium, e.g., in yeasts, neurospora etc.
• Basidiomycota (Club Fungi):
• Basidiomycota, commonly known as club fungi, is a diverse and ecologically important phylum within the Kingdom Fungi.
• Basidiomycota includes some of the most recognizable and economically significant fungi, such as mushrooms, rust, smut, puffballs, toadstools, and shelf fungi. These fungi can be found in various habitats, often forming mycorrhizal relationships with plants or decomposing organic matter.
• Basidiomycota fungi are distinguished by the presence of filamentous hyphae. Most species reproduce sexually with basidia, which are specialized spore-forming structures. Basidiomycota are named after these unique spore forming structures. Each basidium is a club-shaped organs. It is a hyphal cell that typically generates groups of four spores on its tip, referred to as basidiospores. Each individual fungus produces millions of basidiospores and each basidiospore has the potential to give rise to new primary mycelium. Hyphae of primary mycelium are composed of monokaryotic (n) cells. The mycelium of a basidiomycote e.g., Agaricus (Mushroom), consists of mass of white, branched, thread like hyphae that occur mostly belowground. The hyphae are divided into cells by septa. The septa are perforated and allow cytoplasmic streaming between cells.
• Although club fungi occasionally do produce conidiospores asexually, they usually reproduce sexually. A hyphae of a primary mycelium fuses with the monokaryotic (n) hyphae of a different mating type. The nuclei from parent hyphae pair in this cytoplasm but do not fuse. In this way a secondary mycelium with dikaryotic (n+n) hyphae is produced in which each cell contains two nuclei. The secondary mycelium grows into a compact mass called buttons. Each button grows into a fruiting body known as mushroom. A mushroom which consists of a stalk and a cap is more formally referred to as basidiocarp. The walled off ends of tightly packed hyphae become the club shaped basidia. The lower surface of the cap usually consists of many thin perpendicular plates called gills that radiate from the stalk to the edge of the cap. On the gills of the mushroom haploid nuclei of the dikaryotic cells fuse to form diploid zygotes. Meiosis then take place forming four haploid nuclei that move into finger like projections forming basidiospore, which are released later.
• Deuteromycota (Imperfect Fungi):
• These fungi are called "imperfect fungi" owing to the absence of sexual stage in their life cycle. They reproduce asexually by forming conidiospores. The cellular morphology and biochemistry of imperfect fungi trace their ancestry to sac fungi, which have lost the ability to reproduce sexually.
• These fungi lead a saprophytic or parasitic life on plants. They have a well known economic importance. Penicillium, Aspergillus, Alternaria and Fusarium are a few examples of imperfect fungi.
• Despite absence of sexual reproduction, imperfect fungi have a genetic recombination mechanism called Parasexuality. It facilitates the exchange of genetic material between fungal cells by exchanging portions of chromosomes of two nuclei lying in the same hypha., fostering genetic diversity and adaptability.
• 7.5 IMPORTANCE OF FUNGI:
• Fungi are important players in economic gains as well as losses. They decompose organic matter, recycling nutrients in ecosystems. They form symbiotic relationships with plants, aiding nutrient uptake. Fungi are sources of antibiotics, enzymes, and food (mushrooms, yeast). They also have vital roles in research, biotechnology, and as indicators of environmental health. Fungi cause diseases in humans, other animals and plants. They cause huge agricultural damage every year.
• Importance of Yeast:
• Yeast is renowned for its pivotal roles in baking and brewing due to its remarkable ability of producing ethyl alcohol and carbon dioxide from sugars such a glucose by fermentation, where it leaves dough and ferments sugars to create bread, beer, and wine.
• It also has great implications in genetic research, serving as a model organism for scientific exploration. It's simple yet elegant biology, genetic tractability, and resemblance to human genes have unlocked insights into fundamental biological processes.
• Brewing: Yeast, particularly Saccharomyces cerevisiae, converts sugars from malted grains or other sources into alcohol and carbon dioxide. This fermentation gives rise to the diverse flavors, aromas, and alcohol content in beer and wine and also to making bread.
• Baking: In bread-making, yeast acts as a leavening agent. When yeast consumes sugars and produces carbon dioxide gas, it gets trapped within the dough, causing it to rise. This process results in the fluffy, airy texture of bread. Yeast's ability to produce gas is also crucial in other baked goods like pastries and cakes.
• Genetic Research Model: Yeast, especially Saccharomyces cerevisiae, serves as a valuable model organism in genetic research. It's simple and well-characterized genome, along with its similarities to human genes, makes it an ideal subject for studying genetics, cell biology, and molecular processes like mutations, genetic recombination and laws of segregation.
• Biotechnology: Yeast is used in biotechnological processes to produce enzymes, biofuels, and pharmaceuticals.
• Food Production: Yeast is involved in the production of various food items, including cheese, yogurt, and soy sauce.
• Often the first choice eukaryotic organisms for protein production is the yeast (Saccharomyces cerevisiae). Yeast cells can take up foreign DNA and integrate into their genomes. Yeasts also have plasmids that can be used as gene vectors and some time yeasts are better than bacteria at synthesizing and secreting eukaryotic protein. Yeast is currently used to produce a number of proteins. In some cases the same product, for example interferons used in cancer research can be made in either yeast or bacteria. In other cases such as hepatitis B vaccine, yeast alone is used.
• Science, Technology and Society Connections: Discover how fungi act like nature's medicine cabinet, giving us antibiotics and valuable compounds.
• Table : 7.6 Antibiotics Obtained from Fungi:

• MUTUALISM: Lichen and Mycorrhizae:
• Mutualism is the association in which both the partners get benefit. The two key mutualistic symbiotic associations formed by the fungi are lichens and mycorrhizae.
• Lichens: Lichens are an association between a fungus (mostly Ascomycotes and imperfect fungi and a few basidiomycetes), a cyanobacterium or green alga. The top layer, composed of resilient fungal hyphae, is thin. In the middle layer, fungal hyphae intertwine with photosynthetic cells, while the bottom layer consists of loosely packed fungal hyphae that facilitate nutrient transfer within the fungus. Traditionally, lichens were thought to have mutualistic relationships, with the fungus gaining nutrients from the algal cells and the algae receiving protection from drying out. However, recent research suggests that lichen associations may involve a controlled form of parasitism by the fungus on the algae cells.
• Mycorrhizae: Mycorrhizae represent mutually beneficial partnerships between soil fungi and the roots of the majority of plants. This association occurs in 95% of all families of higher plants. Fungal hyphae play an important role by increasing soil contact and surface area, aiding in the direct uptake of essential nutrients like phosphorus, zinc, and copper from the soil into the roots. Plants hosting mycorrhizae tend to grow successfully more than those without these partnerships. Mycorrhizae come in two primary types, each with unique characteristics:
• Endomycorrhizae: These fungi penetrate plant roots, specifically the outer cells, forming coils, swellings, and tiny branches while also extending into the surrounding soil.
• Ectomycorrhizae: These fungi create a protective layer outside the root, growing between cell walls. They are typically associated with trees like pines and firs.
• Edible Fungi:
• In the Orient, Aspergillus tamarii and other imperfect fungi are used in the orient to produce soy sauce by fermenting soybeans.
• Among basidiomycetes, there exist approximately 200 varieties of edible mushrooms, primarily Agaricus, alongside about 70 potentially poisonous ones often referred to as toadstools.
• Some edible mushrooms are cultivated for commercial purposes. Notably, Morchella esculenta, resembling mushrooms, and truffles, known for their subterranean fruiting bodies, belong to the Ascomycotes.
• Edible and poisonous mushrooms can look very much alike and may even belong to the same genus. There is no simple way to tell them apart; they must be identified by an expert. Some of the deadliest mushrooms fall under the Amanita genus, aptly named "destroying angel" (Amanita virosa) and "death cap" (Amanita phalloides). Consumption of a single mushroom from either species can be fatal, while certain mushrooms can induce intoxication and hallucinations when ingested.
• Ecological Impact of Fungi:
• Fungi are ecological powerhouses, influencing nutrient cycling, plant health, soil formation, and even the balance of predator-prey interactions. Their role in ecosystems is intricate and multifaceted, highlighting their significance in maintaining the health and sustainability of the natural world.
• Decomposers and Nutrient Cycling: Fungi serve as nature's recyclers, breaking down dead organic matter, such as fallen leaves and wood, returning vital nutrients to the ecosystem. This decomposition process enriches soil and supports plant growth.
• Mycorrhizal Partnerships: Mycorrhizal fungi form mutually beneficial relationships with plants, enhancing nutrient uptake and contributing to overall ecosystem health.
• Predators and Soil Ecosystems: Predatory fungi regulate populations of microscopic organisms and compete with bacteria, shaping microbial communities in soils.
• Biotransformations and Pollutant Degradation: Fungi play a role in biotransformation of compounds in the environment, including pollutant degradation.
• Carbon Cycling and Humus Formation: Fungi liberate carbon dioxide during decomposition and contribute to humus formation, enriching soil structure and supporting diverse ecosystems.
• Pathogenic Role of Fungi:
• Fungi are causative agents of many plant, animal and human diseases. A few are discussed below:
• Role of Fungi in Plant Diseases: Fungi can cause serious diseases in plants, including epidemic diseases that can destroy complete crops. These tiny organisms threaten all crops and trees. They create problems like leaf spots, wilting, and rotting. Some common plant diseases caused by ascomycotes are powdery mildew, chestnut blight, Dutch elm disease, apple scab and brown rot which attack cherries, peaches, plums and apricots. Diseases caused by basidiomycetes include smuts and rusts that attack a large variety of plants e.g., the cereal crops like wheat and corn.
• Role of Fungi in Animal Diseases: Fungal diseases in animals, including humans, are diverse and can range from mild skin infections to severe systemic illnesses. Some fungi cause superficial infections in which only the skin, hair or nails are infected. Ringworm (Microsporium audouni) and Athlete's foot (Tinea pedis) are examples of such diseases. Candidiasis is caused by Candida yeast and can produce infections in humans, such as oral thrush. In animals, it can lead to conditions like skin and ear infections. Other fungi cause systemic infections that infect internal tissues and organs and may spread through the body. Histoplasmosis is caused by inhaling spores of the Histoplasma fungus, is a serious infection of lungs. Aspergillosis caused by Aspergillus fumigatus is a respiratory fungal infection seen in birds, particularly parrots, and can also affect humans with weakened immune systems. Some strains of Aspergillus flavus produce aflatoxin, a cancer causing mycotoxins in improperly stored grains of peanut, corn etc. Ergotism is caused .purple ergot rye. It causes nervous spasm, convulsion, psychotic delusion and even gangrene. Pneumocystis Pneumonia (PCP) is caused by the fungus Pneumocystis jirovecii and mainly affects individuals with weakened immune systems, such as those with HIV/AIDS.

60-Second Revision

• Zygomycota = conjugating fungi.
• **Ascomycota** = sac fungi.
• Basidiomycota = club fungi.
• Deuteromycota = imperfect fungi.
• **Zygomycota** = zygospores.
• Ascomycota = asci and ascospores.
• Basidiomycota = basidia and basidiospores.
• **Deuteromycota** = conidiospores.
• Examples: Rhizopus, Penicillium, Agaricus, Aspergillus.
• Importance: Decomposition, symbiosis, food, medicine, research, biotechnology, diseases.
• Warning: Do not confuse the four groups of fungi. Zygospores = Zygomycota; Ascospores = Ascomycota; Basidiospores = Basidiomycota; Conidiospores = Deuteromycota. Deuteromycota have no sexual stage. Lichens = fungus + alga/cyanobacterium; Mycorrhizae = fungus + plant roots. Yeast is used in baking, brewing, genetic research, biotechnology, and food production. Antibiotics from fungi include penicillin, streptomycin, tetracycline, erythromycin, fumigatin. Some mushrooms are poisonous. Fungi cause plant, animal, and human diseases.