Zygomycota Characteristics: Come friends today we will learn about Zygomycota Characteristics. The zygomycota are a paraphyletic group of over 1,300 fungal species with different evolutionary origins. These have the common feature of producing zygospores, which are hard and thick walled zygotes, through which sexual reproduction takes place.

The group is a group of six lineages whose relationships remain to be defined: Mucoromycotina, Entomophthoromycotina, Mortierellomycotina, Zoophagomycotina, Glomeromycota and Kixellomycotina. (Zygomycota Characteristics)

Zygomycetes are the group of fungi with the greatest ecological diversity. They can be saprophytes on substrates such as fruit, soil and compost, symbionts in the viscoe of arthropods, munists of plants that form mycorrhiza and pathogens of animals, plants, insects and other fungi. 

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In the food industry, several species are used in the fermentation of food. Rhizopus oligosporus  is used in the preparation of a fermented food obtained from tempeh, soybeans native to Indonesia.

Rhizopus oryzae It is used in the production of alcoholic beverages, in Asia and Africa. Actinomucer elegans  It is used in the preparation of tofu, a common food in Oriental cuisine based on soybeans. They are also used as a yellow pigment for meat tenderizers, margarine.

On the other hand, some species have a negative economic impact. Rhizopus stolonifer and species of the genus Mucor, cause rotting of fruits, especially strawberries.

Chynaphora cucurbitarum  It is a plant pathogen that causes fruit and flower rot of many cucurbits. Species of the genus Mucorales cause life-threatening opportunistic infections in diabetic, immunocompromised and immunosuppressed patients.

General Features

Mucoromycotina constitute the most numerous and best known clade. It includes about 300 species, common in all soils. They can infect plants and other fungi. They have been isolated in clinical samples, they are used in the fermentation of food.

The different lineages that make up the Zygomycota have different common characteristics.

Entomophthoromycotina is the second largest group with about 300 species. This includes saprotrophic and entomopathogenic zygomycetes associated with soil and waste. They can be saprotrophic, facultative pathogens and obligate entomopathogens. It is probably one of the first groups of terrestrial mushrooms.

Mortyrelomycotina contains more than 100 taxa of soil saprotrophic organisms. All species in this subcontinent are soil-dwellers and ubiquitous saprotrophs, some of them even plant symbionts.

The Glomeromycota include over 250 described species that can grow only in the roots of host plants that form arboreal mycorrhiza. There are ancient fossils of about 430 million years in size that are similar to present-day fungi. (Zygomycota Characteristics)

Each subphylum in Kickxellomycotina and Zoopagomycotina contains about 180 species. Many of these fungi are parasites of invertebrates, dinosaurs of arthropods or saprotrophs. Some of them are important as insect pathogens.

classification

The systematization of the fungus is in the process of reorganization. The traditional classification of fungi was based only on morphological and physiological characteristics that do not necessarily reflect evolutionary history.

The modern classification of fungi is mainly based on groups defined by similarities in their DNA sequences.

This new method has replaced the traditional classification schemes. A 2017 study recognized eight fungal phyla, while a year later, another study defined nine sub-kingdoms and at least 18 phyla. Similarly, relationships at the level of family, gender and species have not yet been resolved.

Thus, the interrelationships between species classified in Zygomycota are currently under investigation. It is believed to be an artificial group, of paraphyletic origin, that currently does not constitute a valid taxon.

This group is a group of the taxa Mucoromycotina, Entomophthoromycotina, Mortierelomycotina, Zoophagomycotina, Mucoromycotina, Glomeromycota and Kixcellomycotina.

nutrition

Fungi are heterotrophic, they feed on the nutrients they absorb from the environment. Zygomytes can be saprotrophic, parasitic, or mutualistic symbionts depending on their eating pattern. (Zygomycota Characteristics)

Saprotrophic zygomycetes feed on the wastes of other organisms, such as dead plant matter (leaves, trunks, bark), carcasses or excrement.

The fungus produces enzymes that scavenge from the surrounding environment and accelerate the decomposition of organic matter and the release of nutrients into the environment. Part of these nutrients are absorbed by fungi and another part is used by plants and other organisms.

Parasitic fungi absorb their food from the decomposition of the living tissue of their host, leading to death in most cases.

Fungi that establish mutual symbiotic relationships on the products excreted by their dinners without harming their existence.

Fungal species that form mycorrhiza on a constant source of carbohydrates from the plant. Whereas plants benefit from the greater ability of fungi to absorb water and nutrients, and mobilize minerals.

habitat

Zygomycetes have mainly been isolated in soils, where they colonize any source of easily degradable carbohydrates or proteins.

They can also be associated with the decomposition of waste, animal manure or organic matter.

Parasitic species inhabit the viscera of insects and the tissues of plants, animals and other fungi.

Other species may colonize hospitable or nosocomial environments, posing a serious public health problem.

Reproduction

Fungi of this group present sexual and asexual reproduction.

Asexual reproduction in the mucilage occurs by means of a multinucleate in which unicellular and non-mobile sporangioscopes are produced.

The mucilage not only disperses dry sporangiospores through the air, but also produces less wet sporangiospores by aerosolization. It is an important characteristic that determines its level of pathogenesis.

zygomycoses

More than 30 species of Zygomycota are involved in human infection. Mucus among them is the most abundant. Among fungal infections, zygomycosis is exceptionally severe, with a mortality rate exceeding 50%.

The main access route of Zygomycete fungi to organisms is through the respiratory tract in humans. The first barrier found by spores is the hair cells of the respiratory epithelium. Those who are able to advance find the alveolar macrophages that proliferate the most and destroy them.

Other forms of infection are through infection of a wound or severe trauma, taken orally, or by insect bites.

patients at high risk of infection

Most infections occur in neonates who have not yet developed an adequate immune system or in immunocompromised hosts, transplant recipients and diabetic patients with uncontrolled ketoacidosis and high serum iron levels.

In addition, patients on dialysis treatment with corticosteroids, deferoxamine, immunosuppressive drugs, neutropenia, malnutrition, cytomegalovirus infection and wounds or burns are also at increased susceptibility to develop zygomycosis.

Hospital or nosocomial infections may be caused by contaminated medical equipment, eg, ostomy bag systems, adhesive bandages, tongue depressors, subcutaneous insulin infusion pumps, peritoneal dialysis, intravascular devices. Tea

It can also be caused by contamination during medical procedures such as dental extractions, local anesthesia, intramuscular injection of corticosteroids, vitamins and anticoagulants, nasal packing, graft contamination and during implants.

There are five main clinical manifestations of zygomycosis: ganbebral, pulmonary, gastrointestinal, cutaneous, and disseminated:

rhinocerebral zygomycosis

It is the most common form in neutropenic hematologic and diabetic patients. Initial symptoms are nonspecific, including headache, altered mental status, fever and eye syndrome, tearing, burning or periorbital anaesthesia.

Unilateral vision changes and other changes including ptosis, proptosis or loss of extraocular muscle function are signs of a progressive transition towards the retro-orbital region or the central nervous system.

pulmonary zygomycosis

Pulmonary zygomycosis usually occurs with profound neutropenia, hematologic malignancies with corticosteroids or in patients with diabetes mellitus. Symptoms are not specific and include fever, chest pain and cough.

Gastrointestinal zygomycosis

This is a very rare form of infection. It is associated with severe malnutrition and premature birth. It is believed that the infection is the result of ingestion of the fungus.

Symptoms are nonspecific, and include fever, pain, vomiting, diarrhea, and constipation. Infection can lead to ischemic infarction and ulceration.

Cutaneous zygomycosis

Infection develops in patients who have suffered burns or other trauma. It is caused by direct vaccination during an accident or it can be nosocomial.

Manifestations of the disease include erythema, pus, abscess formation, tissue swelling, necrosis and pain in the infected area.

Tissue necrosis may progress to gangrenous cellulitis. Cutaneous infection may be secondary in patients with disseminated infection of the respiratory tract.

Disseminated zygomycosis

When two or more non-infectious organs are involved, the infection is considered a deficiency. This form is the most difficult for the patient to control and poses the greatest danger to the patient.

They often involve colonization of the pulmonary and central nervous systems, with the lungs being the site of primary infection. Other internal organs may be invaded during colonization, among others, the spleen, liver and even the heart, which causes pain in the infected organ.