Rhizopus stolonifer is more commonly known as black bread mold. Rhizopus specifically means any rot causing fungi. This type of mold also has a synonym name of Rhizopus nigricans. Rhizopus stolonifer is classified as a member of the Eukarya because it has cells that are organized into complex structures that are enclosed within membranes, along with membrane bound nuclei and other organelles in those cells. The kingdom Fungi consists of organisms that are heterotrophic.
Rhizopus stolonifer is a mold that lacks chlorophyll, is non-motile, filamentous, and a decomposer of organic material. Rhizopus stolonifer belongs to the phylum Zygomycota because it sexually produces zygospores and is considered saprophytic and parasitic.
The Zygomycetes all have chitenous cell walls in a coenocytic mycelium and they lack motile spores. Rhizopus stolonifer is a member of the Mucorales because it is fast growing, with wide hyphae, that lack septa or is coenocytic, and grow within a substrate. Rhizopus stolonifer is also considered a member of the Mucorales because it is a major saprophyte, or grows and acquires nutrients from dead and decaying matter.
Rhizopus stolonifer is a part of the family Mucoraceae due to the key feature of a swollen extension of the sporangiophore, called the columella. It looks like a balloon within the sporangium and it often persists after the spores have been released. Rhizopus stolonifer is a member of the Rhizopus species because it is a rot causing fungus that has columnar hemispherical aerial sporangia anchored to the substrate by rhizoids.
There are multiple species of Rhizopusbut Rhizopus stolonifer earned this species name because it is a black mold that grows on bread and its spores float around in the air. Rhizopus stolonifer also uses rhizoids as a way to anchor itself to the vast array of substrates it can come in contact with. To identify Rhizopus stolonifer look for either a grayish fluffy mass or a blue or yellow colored coating on the substrate.
Black spores are also visible to the eye on the surface of the substrate, which may look like black specs. The interesting looking fungi can appear on stale bread, damp leathers, and decaying fruits of which are kept at favorable temperatures. To explore more about the kingdom of Fungi, the other classifications specifically of Rhizopus stoloniferand to find out more about other similar interesting information please click here.
I created the phylogenetic tree below and it is modified from an article in the journal Bioscience, Biotechnology, and Biochemistry. In order to create this phylogenetic tree composed on the genus Rhizopus, molecules of the rDNA of the species of the genus were sequenced.Found this incredibly looking glassy diatom in the water which I collected from a beach in south India Suryalanka Beach, Andhra Pradesh.
It is a type of green algae which is not-so-commonly found on freshwater habitats. It lives in spherical colonies. It was first reported by Antony van Leeuwenhoek in Each colony may contain aboutsingle celled algae.
Somatic Phase of Rhizopus Stolonifer (With Diagram) | Zygomycetes
The individual algal cells are linked to each other by thin strands of cytoplasm which facilitates the whole colony to swim in a synchronized fashion. These cells have small red eyespots which enable the colony to swim towards light. It also shows distinct anterior and posterior poles. Volvox established its colonial lifestyle million years ago. The colonial development was possibly the first step against multicellular organisms for natural selection. The difference between a multicellular organism and a colonial organism is that individual organisms from a colony can if alienated survive on their own while cells from a multicellular organism cannot.
Volvox belongs to the genus chlorophytes, accordingly volvox cells have chlorophyll and makes their own food by photosynthesis.
Most volvox colonies have spheres inside. Later when the parent crumbles, the daughters upturn their flagella inside out. Volvox also shows sexual reproduction. It develops special germ cells. Male and female colonies form different germ cells. Male colonies release abundant number of sperm cells formed by division while female colonies do not divide instead they enlarge to form an ova or egg. After fertilization, the zygotes become enclosed in a cyst and are released from the parent colony when it dies.
Molds are fungi that grow in the form of translucent multicellular filaments called hyphae and a network of these hyphae is known as mycelium.In this article we will discuss about the asexual and sexual reproduction of rhizopus. A dome-shaped columella Fig. The protoplast of columella is in continuation with that of sporangiophore.
The space between columella and wall of sporangium is known as spore sac. It remains Filled with sporangiospores or aplanospores. Each sporangiospore is ovoid, non-motile, unicellular and multinucleate structure.
There is no flagella on the spores. Spores come out on dehiscence of sporangium and germinate immediately by forming new mycelium. It takes place by the fusion of multinucleate gametangia. Species are dioecious or heterothallic. Developing gametangia are known as progametangia.
These are filled with cytoplasm and nuclei in their swollen tip. Fusion of two gametangia takes place. Around this fusion product, a thick, spiny wall develops, and now it is called zygospore. Zygospore germinates meiotically by producing a long sporangiophore bearing a sporangium at the tip.
Top Menu BiologyDiscussion. Reproductive Structures of Pythium With Diagram. Symptoms of the Disease Phytophthora. This is a question and answer forum for students, teachers and general visitors for exchanging articles, answers and notes.
Answer Now and help others. Answer Now. Here's how it works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top.Rhizopus stolonifer exhibits both sexual and asexual reproduction. The asexual phase occurs more frequently.
The surrounding condition in which the mold resides, is the factor that causes either type of reproduction by the mold. Before learning the specifics, click here to view how Rhizopus stolonifer, as a member of the phylum Zygomycota, compares to other phylum within the kingdom of Fungi.
When the mold comes in contact with a substrate, such as bread, it first spreads over the surface and penetrates it while sending hyphae inward to absorb the nutrients. Rhizopus stolonifer grows primarily as mycelia, which consists of long filamentous cells, or hyphae, that lack cross walls, known as septa.
The lack of septa enables the mold to be named coenocytic. Coenocytic means that the mold is a multinucleate cell enclosed by one cell wall that contains chitin. In asexual reproduction, special non-motile hyphae called sporangiophores produce sporangia that form in an upright fashion. The sporangia at the tips of the upright hyphae develop as bulbous black portions.
Branching structures, called rhizoids, anchor the fungus into the substrate, releasing digestive enzymes and absorbing nutrients for the fungus. When conditions are good the sporangia, containing numerous haploid spores of which are produced through mitosis, release the spores into the surrounding atmosphere. These spores then may land on a moist surface and the life cycle repeats.
Side note: Rhizopus stolonifer spores are usually dispersed in hot dry weather and they contain allergic proteins, which can cause respiratory and nasal symptoms in humans, such as coughing, chest discomfort and allergic reactions. Note: Rhizopus nigricans is a synonym for Rhizopus stolonifer. To learn about another fungus that has a similar life cycle as Rhizopus stoloniferplease go to Aspergillus fumigatus.
Proceed on to learn about the interactions Rhizopus stolonifer has with other things. Black Bread Mold Rhizopus stolonifer. Asexual Reproduction In asexual reproduction, special non-motile hyphae called sporangiophores produce sporangia that form in an upright fashion. Zygospores are thick-walled, which make them highly resistant to environmental hardships. The word zygospore comes from the Greek word zygos, which means joining.
The zygospores are the only diploid phase of Rhizopus stolonifer reproduction. They are composed of two suspensor cells, which are the former gametangia or hyphae. There is a suspensor cell on either side of a large, rough, dark brown spore.Rhizopuscosmopolitan genus of some 10 species of filamentous fungi in the family Rhizopodaceae formerly Mucoraceaein the order Mucorales.
Several species, including Rhizopus stolonifer the common bread moldhave industrial importance, and a number are responsible for diseases in plants and animals. The majority of Rhizopus species are saprobic decomposers and feed on a variety of dead organic matter, though some species are parasitic or pathogenic.
Rhizopus fungi are characterized by a body of branching mycelia composed of three types of hyphae: stolonsrhizoidsand usually unbranching sporangiophores. The black sporangia at the tips of the sporangiophores are rounded and produce numerous nonmotile multinucleate spores for asexual reproduction. Rhizopus can reproduce sexually when two compatible and physiologically distinct mycelia are present.
The rapidly growing colonies fade from white to dark as they produce spores and are similar to cotton candy also called candy floss or fairy floss in texture.
Observe Mold Up Close
Many members of Rhizopus are commonly used in industrial processes. In Asia several species are important in some foods, such as tempeh, and in many traditional alcoholic beverages.
Mucormycosis also called zygomycosis is a rare and serious disease caused primarily by R. The infection invades blood vessels in humans and other animals and can progress to other areas of the body, including the brain and lungs. The disease has an overall mortality rate of 50 percent, though outcomes can vary widely and are strongly affected by preexisting conditions.
A number of postharvest plant diseasescollectively known as storage rot, are caused by R. In warm conditions, these fungi can affect the soft tissues of harvested fruitsoften causing a watery leakage and rendering them inedible. Leak disease in strawberries and tomatoessoft rot and ring rot in sweet potatoespole rot in tobacco leaves, and fruit rot in papayas and stone fruits are all storage rot diseases caused by these Rhizopus species.
Preventive fungicides are often sprayed postharvest to avoid crop losses from these diseases, and cold storage during transport can prevent or slow their spread. Article Media. Info Print Cite. Submit Feedback. Thank you for your feedback.
Rhizopus fungus genus. Written By: Melissa Petruzzello. See Article History. Get exclusive access to content from our First Edition with your subscription. Subscribe today.Hyphae broad, not or scarcely septate; rhizoids and stolons present; sporangiophores brown, solitary or in tufts on the stolons, diverging from the point at which the rhizoids form; sporangia rather round; apophysis absent or scarcely apparent; sporangiophores ovoid. Rhizopus is recognized by the presence of well developed rhizoids situated at the point where sporangiophores are attached to the stolons.
In contrast to MucorRhizomucor and Absidiathe sporangiophores are often unbranched and grouped in tufts. Rhizopus are cosmopolitan, frequently isolated from soil and agricultural products cereal, vegetables, etc.
Certain species are plant pathogens. Rhizopus is the principal agent of mucormycosis formally zygomycosis. This rapidly progressing infection is characterized by the cerosis of tissues and the production of infarcts in the brain, the lungs, and the intestines. Primarily, it is patients suffering from diabetic ketoacidosis, malnutrition, severe burns, or immunocompromising conditions who are most at risk to develop this type of infection.
Hensyl, William R. Stedman's Medical Dictionary25th ed. Germain, Guy and Summerbell, Richard, Ph. Identifying Filamentous Fungi1st ed. Larone, Davise, H. The Oxoid Vade-Mecum of Microbiology.
Unipath Ltd. Reverse: Pale white.
Growth Rate: Very rapid growth. Maximum Growth Temperature.
Rhizoid Length um. Sporaniophore Length um. Sporangium Length um. Sporangio- spores. Slightly elongated; distinct apophysis. Equal size, average length um; smooth to slightly striated; almost round to slightly elongated.
Variable size, average length um; striated; elongated to lemon-shaped. Variable in size, average length um; very striated; elongated to polyhedric.Molds are the common fungi found on the surface of stale food. Molds are fungi that grow in the form of translucent multicellular filaments called hyphae and a network of these hyphae is known as mycelium.
Special strands of hyphae connecting fungal bodies are called as stolons. The soft white fluffy appearance on the surface from above is due to the presence of mycelium.
The dusty texture of many molds is caused by generous number of asexual spores formed by differentiation in the sporangium. Many of these spores are colored, making the fungus much more obvious to the human eye. Rhizopus reproduces asexually by sending up vertical stalk called sporangiophore which lumps at the tip to produce a sporangium. The cytoplasm in the sporangium divides repeatedly to release a mass of spores, each with a nucleus.
When the sporangium breaks open, the spores are dispersed in the air, and each can grow to form a new mycelium on an apt medium. Effective mating results in the formation of zygospores at the point of contact.
Fungus feed on deteriorated organic matter through mycelium. The hyphae secrete digestive enzymes onto the food surface, which break down the complex biological polymers into smaller monomers. These monomers are then absorbed into the mycelium by facilitated diffusion and active transport.
Came to know about this blog through Abu Baker, astonished to see a wonderful invisible to a human eye world, would love to see more such things, one humble request is about the scientific terminology and jargons which if avoided would be of great help to people like me to understand the subject easily. You are commenting using your WordPress. You are commenting using your Google account. You are commenting using your Twitter account. You are commenting using your Facebook account. Notify me of new comments via email.
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