Fungi and the environment

Like bacteria, fungi play the role of decomposers in nature.

As we have already seen, decomposers are instrumental in maintaining the natural balance of ecosystems: they break down the corpses and residues of living things (such as faeces and urine), absorbing only a part for their nutrition. The rest of the decomposition mineral salts are left in the environment.

Thus, the decomposers collaborate in the recycling of materials in soil and water and play an essential role in food chains and webs.

Algae and fungus association

Some fungi live in association with algae or cyanobacteria. This association, the mutualism, is advantageous to both and is called lichen.

Lichen on the rock

Economic Importance of Fungi

About two hundred types of mushrooms are used for human consumption. Some species are widely cultivated, such as basidiomycete Agaricus campestris; ascomycetes such as Morchella esculenta, when dried, are a very fine delicacy.

Agaricus campestris

Bread production

Yeasts are microscopic fungi used since ancient times in the preparation of fermented foods and beverages. The yeast Saccharomyces cerevisiae, used in the manufacture of bread and alcoholic beverages ferment sugars for energy, releasing carbon dioxide and ethyl alcohol. In the production of bread is the carbon dioxide that matters; The microscopic bubbles of this gas, eliminated by the yeast in the dough, contribute to making the bread light and soft.

Alcoholic beverage production

The production of different types of alcoholic beverages varies according to the fermented substrate, the type of yeast used and the different manufacturing techniques. For example, barley fermentation produces beer, while grape fermentation produces wine. After fermentation, certain beverages undergo distillation processes, which increases their concentration in alcohol. Examples of distilled beverages are spirits, or drips, obtained from fermented sugar cane, whiskey from fermented cereals such as barley and rye, and sake from fermented rice.

Cheese production

Certain fungi are used in cheese production and are responsible for their characteristic flavor. The fungi Penicillium roqueforti and Penicillium camemberti, for example, are used in the manufacture of roquefort and camembert cheeses respectively.

Penicillium roqueforti (viewed under electron microscope, artificially colored)
Copyright Dennis Kunkel Microscopy, Inc.

Roqueforti Cheese

Fungi and production of pharmaceutical substances

It was from the ascomyceto Penicillium chrysogenum originally extracted from penicillin, one of the first antibiotics to be successfully used to combat bacterial infections.

Certain fungi produce powerful toxins that have been the subject of pharmaceutical research. Many fungi produce substances called cyclopeptides, capable of inhibiting messenger RNA synthesis in animal cells. Simply ingesting a single fruiting body (mushroom) of the basidiomycete Amanita phalloides, for example, to cause a person to die. A fungus widely studied from a pharmaceutical point of view was ascomycet Claviceps purpurea, popularly known as ergotine. From it was originally extracted lysergic acid, or LSD, hallucinogenic substance made famous in the 1970s.

Ergotin grows on cereal grains, mainly rye and wheat. Ergot contaminated cereals have in the past caused mass poisoning, with many deaths. Since the sixteenth century, midwives had known a pharmaceutical property of ergotine: if ingested in small quantities, it accelerated uterine contractions during labor.