[Biology Class Notes] on Nutrition in Fungi Pdf for Exam

Fungi is a member of the Eukaryotic family. Fungi are absent of Chlorophyll, so they are known as Achlorophyllous Species. Further, Fungi cannot synthesize their own food. It starts absorbing the dissolved molecules from other species. It is known as Heterotrophs. Fungi will use digestive enzymes to extract necessary Carbohydrates, Water from the Organic Substance. 

Explain Nutrition in Fungi

Like plants, Fungi do not require Carbon dioxide and light as a source of Carbon for their food. The Fungi get attached to the organic matter and absorb Carbohydrates. It absorbs and metabolizes various soluble Carbohydrates like Glucose, Fructose, Xylose, and Sucrose. Also, Fungi have the ability to absorb and process insoluble carbohydrates like cellulose, hemicellulose, and starches along with complex hydrocarbons such as lignin. Many Fungi even absorb Proteins as a source of carbon and nitrogen. Fungi will produce digestive enzymes to polymers extracellular, this helps to utilize insoluble carbohydrates and Proteins. Using the biological catalysts, an enzyme secreted on the surface of the Fungi starts to secure its food. The digestive enzyme helps to break down the food and the root-like substance present of the Fungi called hyphal walls absorbs the food. Food in the form of liquid can only enter into hyphae, the entire mycelial surface of Fungus has the capability to absorb water and minerals entered through hyphae. This is how Fungi obtain their food. For example, The surface of the rotten fruits became soft. This is because of fungal enzymes. Many parasitic Fungi have some specialized features like absorptive organs. This is known as haustoria.  

Fungi are broadly classified into three types, based on how Fungi obtain their food.  

Types of Nutrition in Fungi

• Saprotrophic Fungi – Fungi obtain food from dead and decayed materials.

• Parasitic Fungi –  Get feed from living Organisms and destroy them 

• Symbiotic Fungi – Grow in a living Organism and get mutually benefited. 

Saprotrophic Fungi

Like bacteria, saprotrophic Fungi have a huge responsibility to decompose the organic matter in the earth. The saprotrophic Fungi takes responsible for decaying and decomposing the foodstuffs. Many saprotrophs have the ability to destructure and destroy giant structures like timber using the digestive enzyme mycelia. The tropical region’s humidity and temperature support the growth of Fungi. The nutritional availability takes responsibility to determine the growth of saprotrophs.

Each Fungus synthesizes the enzyme with different chemical composition. But all Fungi have the same morphological characteristics in culture media. Required carbon is supplied to the Fungi in the form of sugars or starch. Most Fungi absorb the sugar in the form of fructose, maltose, mannose, fructose, and in some least cases sucrose. For a nitrogen source, Fungi compose proteins and produce proteoses, amino acids, and peptones. Some Fungi absorb ammonium compounds and nitrates as a nutrient source. Also, Fungi have the ability to combine and fix atmospheric nitrogen using suitable compounds. To vigorous the growth of Fungi some chemical components like phosphorus, sulfur, magnesium, potassium, manganese, iron, zinc, copper are essential.  Also, the least amount of calcium, molybdenum, and gallium are required for species growth.

Fungi require oxygen and hydrogen, which will absorb in the form of water. Also, Fungi require vitamins and minerals like thiamine and biotin to boost the growth of Fungi and reproduction. As Fungi are aerobic Organisms, they require free oxygen for their survival. During its anaerobic condition, it undergoes a fermentation process. Many industries are using saprotrophic Fungi for their fermentation process.  

For example, the most known saprotrophic Fungi, which undergo an anaerobic process are Neocallimastix. This can act upon the plant cell wall components such as Xylem and cellulose. But it cannot act on the animal cell walls. 

Parasitic Fungi

Parasitic Fungi use to live on living Organisms by invading them. These types of Fungi start extracting Nutrients from the living cytoplasm. This causes disease and death to the host. Most pathogenic fungi are parasites of plants, which enter into the body through the natural opening present in plants like stoma, lenticel in a stem, and broken plants. This causes great damage to the crops. The spores of a pathogenic Fungus fall on the leaves and stems of plants and increase infection of a plant.  The tube grows on the surface of the host and absorbs food for Fungi, this invades the tissues and cell walls. 

Parasitic Fungi in Humans

Many pathogenic Fungi cause disease in human beings and animals. The parasitic Fungi generally enter the body through a wound in the epidermis. This may enter through insects. For example, parasitic Fungi  Claviceps purpurea causes ergotism in human beings. This disease is widely spread among middle-aged people in northern Europe. Other fungal diseases that affect humans are ringworm, aspergillosis, coccidioidomycosis, histoplasmosis, and athlete’s foot. People infected by HIV are mainly due to agent acquired immunodeficiency syndrome (AIDS) weakens the immune system. This is mainly due to the parasitic Fungi called Aspergillus fumigatus.  

Symbiotic Fungi

The Fungi grows in the other Organism and it does not cause any harmful effects for the living Organism. Here, both the living Organism and Fungi get mutually benefited. The symbiotic Fungi are of two types. They are mycorrhizae and lichen. 

Mycorrhiza shows the mutual relationship between the Fungus and plants.  This Fungus grows on the root of plants. The Fungus avails its food from the soil and takes shelter from the plants. Likewise, plants utilize the mycelia of Fungi to absorb Nutrients and water.  

Lichen shows the mutual relationship between Fungus and photosynthetic Organisms. These Fungi grow in green alga or plants. Here Fungus gets food from photosynthesizers meanwhile photosynthesizers avail essential Nutrients from Fungi, This method explains the nutrition in Fungi. 

Predation

Predation is a mode of nutrition for the amoeba. It is very much similar to the mushroom mode of nutrition. Predation catches the microOrganism from the atmosphere through hyphae present in the Fungi and synthesizes the enzyme to break down the cell wall of the Organism and extracts all necessary Nutrients from it. This is how Fungi obtain their food.