The 10 Most Common Microscopic Fungi

Anthony Golden
The 10 Most Common Microscopic Fungi

The microscopic fungi They are very small organisms and are part of the Fungi kingdom. They can be unicellular or multicellular, like yeasts and molds, respectively.

The nutrition of fungi is heterotrophic, so they need to feed on processed organic substances. These do external digestion by secreting enzymes. After digestion, they absorb nutrients.

Candida albicans, microscopic fungus

Fungi can be parasites (they feed on their host: ringworms, ergot, athlete's foot), saprophytes (they feed on decomposing matter), or symbiotic (algae forming lichens or plant roots in the micro-crusts).

The fungi are branched and generally filamentous. They lack chlorophyll but have rigid cell walls where they contain chitin and / or cellulose. They are mostly terrestrial.

The Fungi kingdom or kingdom of fungi has around 611,000 species, a number even higher than that of plants (which have around 212,000 species).

Not only do fungi have a wide range of variety, sizes and shapes, but also a host of important uses and functions that regulate the ecosystem and even certain processes of the human body..

In this case, various species of fungi that are not so easy to see with the naked eye will be studied. They are called microscopic fungi and some of them have very interesting and peculiar roles in some specific conditions..

List of microscopic fungi

Candida albicans

Candida albicans in a laboratory culture. Source: CDC / Dr. William Kaplan [Public domain]. Source: Wikimedia Commons.

It is a saprophytic yeast (classified as an asexual diploid fungus) that proliferates only within the human body.

It is usually found in moist areas of the body, such as the mouth, the small and large intestines, and the vagina.

It is usually kept in check by the immune system and actually plays a beneficial role in the processing of sugars during digestion..

However, if for any reason (such as low defenses or eating disorders) the fungus grows excessively, it can generate a fungal disease called candidiasis (for example, it is very common to see this develop in patients with HIV, who already have damage to your immune system).

This disease produces different conditions in the areas where the fungus is lodged, such as vaginitis, vaginal fungi and infections in the skin, in the oral cavity or in the intestinal tract.

Penicillium chrysogenum

Penicillium chrysogenum

This is a species of fungi of the Trichocomaceae family best known for being the best producer of various metabolites, among which are the beta-lactam antibiotic penicillin, discovered by accident by the famous British scientist Alexander Fleming in 1928.

It is necessary to remember that this medicine is used to treat diseases that were believed incurable until its discovery after the beginning of the 20th century..

Cryptococcus neoformans

Cryptococcus neoformans ink stain

This fungus can live on plants and animals. It is a monomorphic fungus that is transmitted by inhalation.

It is frequently found in the droppings of birds such as pigeons. In humans, it can cause pulmonary cryptococcosis and atypical acute pneumonia. The main disease it generates is meningitis.


Aspergillus niger. Source: Taken and edited from: Mogana Das Murtey and Patchamuthu Ramasamy [CC BY-SA 3.0], via Wikimedia Commons.

It is filamentous and is made up of chains of cells called hyphae. Its natural habitat is hay and it also tends to develop in the soil on decomposing matter..

It is usually easily found and its role is very important in the degradation of organic matter. It can be found in hospitals, the ground, construction material, among other places.

In humans, this fungus usually causes onychomycosis (nail infection), otomycosis (ear infection), allergic sinusitis, among other diseases.

Trichophyton rubrum

Trichophyton rubrum

It is an anthropophilic dermatophyte fungus that usually causes diseases such as athlete's foot and ringworm..

It was described in 1845 for the first time and its development can be slow or moderately fast..

Rhizopus nigricans

Rhizopus nigricans

This is a spore mold found on bread. It belongs to the genus Rhizopus, to which the aerial hemispheric columnar sporangia fungi belong.

Alternaria alternata

Alternaria alternata

This particular fungus is characterized by being pathogenic. It can cause leaf spots and diseases in various plant species, such as rot and discoloration..

In people it can cause upper respiratory tract infections in addition to asthma.

Mucor corymbilfer

Mucor corymbilfer. Source: Thiedbold [CC BY-SA 4.0 (] via Wikimedia Commons)

This species of fungus is saprophytic and lives in the soil. Usually found in moldy bread and rotting potatoes.

Mucor mucedo

Mucor mucedo

Like the previous species, this fungus is saprophytic and it is common to find it in the soil. It is the cause of the spoilage of baked foods, fruits and insects.

Saccharomyces cerevisiae 

Saccharomyces cerevisiae

This unicellular fungus is the yeast used in industries to make food such as bread, beer and wine..

Its life cycle alternates between the haploid and diploid forms. Their way of reproduction is asexual.

Schizosaccharomyces pombe

Schizosaccharomyces pombe. Source: Tiina Tamm [CC BY-SA 3.0 (] via Wikimedia Commons)

It is a species of yeast, a single-celled fungus that is used as a model organism for study in molecular biology and cell biology to study the cell cycle.

It is also called "fission yeast" in English, a kind of yeast. It measures 3 to 4 micrometers in diameter and is shaped like a cane.

In 1893 it was isolated for the first time from an African beer. In the Swahili language, his name means beer.


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