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Fungi are grouped based on the characteristics of the spores produced and the shape of the fruiting bodies formed during the reproductive phase. Fungi that have clearly demonstrated the sexual level are called perfect fungi (perfect fungi ) while fungi that have no clear sexual level are called imperfect fungi ( imperfecti fungi ).
Well, on this occasion we will discuss about the definition, characteristics or characteristics, body structure, reproduction (reproduction), examples and the role of Zygomycota for human life. For that, please read carefully the following explanation. Happy learning and hope you can understand.
Definition of Zygomycota
Zygomycota are also known as the coenocytic true fungi . The well-known types of fungi from this group are black bread molds or Rhizopus sp . The division Zygomycota has members that almost all live in terrestrial habitats. The body is multicellular, the hyphae are senositic, that is, they do not have a nucleus with a haploid nucleus, there are hyphae that function as food absorbers (rhizoids) and connectors (stolons).
Currently known about 600 species including Zygomycota. All of these fungi produce only nonmotile spores (aplanospores) and do not produce traveling spores (zoospores). This shows the progress of the evolutionary level from primitive fungi that live in water to more advanced fungi that live on land. Zygomycota are mostly found in moist soils rich in organic matter. Some live as saprophytes and others are parasites on plants, animals, and humans.
Zygomycota Characteristics
The name Zygomycota comes from the type of sexual self-propagation, especially in the formation of zygospores. Zygospores occur due to the fusion of two gametangia that connect the two parent hyphae like a connecting bridge. The characteristics of fungi belonging to the division Zygomycota are:
- The body is multicellular (multicellular).
- Not chlorophyll that are heterotrophic.
- This group of fungi generally lives as a saprophyte and absorbs food from dead organisms.
- Only a small percentage are parasites living on some kind of a living creature.
- Nearly all of them live on terrestrial habitats.
- Hyphae is not insulated and is senositik (having multiple cores).
- Hyphae serves to absorb food, called rhizoid.
- The cell wall composed of chitin, has no zoospores so that the spores are walled cells. These spores are scattered everywhere;
- Breeding asexually conducted with spores from the sporangium which has been broken. Some hyphae will grow and end to form a sporangium. Sporangium contains spores. These scattered spores will grow into new mycelium;
- The proliferation of sexually done by fusion of two hyphae, hyphae are the female and male hyphae. Male hyphae are hyphae that provide the contents of their cells. Female hyphae are hyphae that receive the contents of their cells. This reproduction is carried out by gametangium of the same shape (male hyphae and female hyphae) which contain many nuclei. Next, the gametangium copulates.
- Produce zygospores as a result of sexual reproduction.
- Do not have a fruiting body.
- Some hyphae stand up and form sporangiofor, and at the end there sporangiofor spherical sporangium. In this blackish sporangium there are vegetative spores.
- Resistant to bad environmental conditions and dry.
Zygomycota Body Structure
The body of Zygomycota is composed of senocytic hyphae. Septa are only found in the hyphae of the body parts that make up the reproductive organs. Sexual reproduction through the fusion of gametes to form zygospores. The most readily available example of a member of this division is Rhizopus stoloniferus .
If a fungus has no hyphae (septa) or hyphae senositivity, then the fungus must be included in the Zygomycota group. So that the hyphae are not insulated is a characteristic of Zygomycota.
The Zygomycota group has three types of hyphae , namely hyphae that spread on the surface of the substrate called stolons , hyphae that penetrate into the substrate such as roots are called rhizoids , and hyphae that rise upwards and form sporangium are called sporangiophores . Sporangium or spore box will produce sporangiospores / spores.
Several types of fungi from the Zygomycota group live in the soil, in symbiosis with the roots of higher plants. Coexistence between roots and fungal filaments of this kind is called mycorrhiza , which generally occurs when the roots are young. This symbiosis benefits both parties.
Fungi obtain food in the form of organic substances from plant roots, while the absorption of water and minerals from the soil increases because it is assisted by fungi. In addition, fungal hyphae produce hormones that stimulate plant growth.
Zygomycota's Way of Life
Most of the Zygomycota live in saprobe (decomposers) in the soil, on the remains of dead or decaying organisms, and on foods such as tempeh, rice and bread. Some of the Zygomycota species live in a symbiotic mutualism on plant roots by forming mycorrhizae.
The symbiotic relationship between Zygomycota and plants is that Zygomycota will obtain nutrients in the form of organic substances from plant hosts, while the roots of host plants can increase the absorption of water and minerals from the soil. There is also a type of parasitic fungus Zygomycota that causes disease, such as the fungus that causes rotting of sweet potatoes.
How to Reproduction Zygomycota
As previously explained, Zygomycota fungi reproduce in two ways, namely asexually (vegetatively) by producing spores and sexually (generatively) by the fusion of two hyphae (male and female) through the conjugation process. The stages of reproduction of Zygomycota fungi asexually and sexually are shown in below.
Asexual Reproduction Stages
- The tips of the hyphae form sporangium bubbles that produce spores.
- When the spores fall in a suitable place, they will grow into new hyphae.
- The hyphae branch to form a mycelium.
- The body of the fungus consists of a rhizoid, a sporangiophore with its sporangium, and a stolon.
- Sporangium produces new spores.
Sexual Reproduction Stages
- The two ends of the hyphae are different, namely hyphae – and hyphae + touching.
- The two ends of the hyphae swell to form a gametangium which contains many haploid nuclei.
- The haploid nucleus of the gametangium fuses to form a diploid zygospore.
- The zygospore germinates and grows into a sporangium.
- In the sporangium meiosis occurs and produces haploid spores. Haploid spores come out, if they fall in a suitable place, they will grow into hyphae.
Zygomycota Life Cycle
Cycle or life cycle of the fungus Rhizopus stolonifer growing on bread, showing the sexual and asexual cycles of Zygomycota.
While asexual reproduction by germination (germination) spores. The spores are stored in the sporangium (spore box). When the spores mature, the sporangium will burst, allowing the spores to be carried by the wind. If the spores fall in the right place, the spores will grow into new hyphae.
Sexual or sexual reproduction is done by conjugation . Sexual reproduction occurs when two "different" ends of the hyphae come into contact. To make it easier to distinguish the two hyphae, they are written by putting a sign (+) and a sign (-), namely hyphae (+) and hyphae (-). The two ends of the hyphae swell to form the progametangium which will become the gametangium.
The two gametangia fuse into a single body called a zygospore. Each haploid nucleus of the gametangium (+) fuses with the haploid nucleus of the gametangium (-) to become a diploid nucleus. The walls of the zygospores are thickened so that they are resistant to unfavorable environmental conditions for a long time.
If environmental conditions allow, sporangium will grow from the zygospore and the diploid nuclei in it will divide by meiosis into haploid nuclei. Sporangium that is ripe will burst, haploid spores come out and grow into new hyphae, to continue their life cycle. This fungus undergoes a brief diploid lineage.
Examples and Roles of Zygomycota
Zygomycota have several types that are easy to find in everyday life. Some of them are molds in food. These types of mushrooms include:
- Rhizophus stolonifera, this fungus appears as white threads, has Rhizoid and stolon. It is a saprophyte that lives on soybean meal and is useful in making tempeh. Rhizophus oryzae, which is found in tempeh yeast, has the power to break down egg whites and fat. Therefore, he plays a role in the manufacture of tempe and white oncom. Tempe mushrooms have hyphae that are useful for absorbing food from soybeans. Within two to three days, the collection of hyphae will wrap the soybean which is then called tempe. In addition to tempeh, this fungus can also grow in damp places.
- Rhizophus oryzae, found in yeast tape and used for the manufacture of sake (Japanese typical drink).
- Rhizophus olygosporus, fosters the formation of tempeh, which can help decipher the soy protein into simple protein and amino acids, with the help of enzymes released. Because he is able to decompose, so it has the same function with bacteria .
- Rhizophus nigricans, this fungus can produce fumaric acid.
- Rhizopus pilobolus are often found growing on horse manure has sporangium can show fototropi motion, that motion grow bends the sporangium to the direction of the light.
- Mucor mucedo , these fungi are saprophytic life. Often found in bread, food scraps and livestock manure. The mycelium of this fungus develops in the substrate. Has a sporangium equipped with sporangiophores.
- Mucor javanicus , role in making fermented because this fungus contained in the fermented yeast. This fungus is a living thing that has the power to convert flour into sugar.
- Entomophthera culicis , is used to control the population of mosquitoes Aedes aegypty (vector-borne dengue fever). This is because this fungus can live as a parasite in the mosquito's body cavity, then it will eat away at the inner mosquito's body membrane so that over time the mosquito will die.
- Entomophtora muscae parasite in the fly.
- Basidiobolus ranarum cause disease in humans.
- Pilobolus sp. This fungus is often called ' the thrower hat ' or cap thrower , because when sporangiumnya ripe, this fungus can hurl as far as 8 meters. The spores then attach to grass or other plants. When the plant is eaten by animals, the attached fungal spores will germinate in the digestive tract and will grow in the feces that the animal excretes.
