Rhizopus Characteristics & Uses


Rhizopus is a genus of filamentous Saprophytic fungi that is found in soil, decaying fruits and vegetables, animal excreta, and stale bread. They are cosmopolitan in occurrence since they are found in air, water, soil, and inside or outside plants and animals. They have a cottony appearance and grow at a rapid rate on suitable organic matter. Rhizopus is a coenocytic (multinucleated) fungi with sporangia, and aseptate mycelia differentiated into stolons, rhizoids, and sporangiophores. The mode of reproduction in Rhizopus is sexual, asexual, and vegetative. Rhizopus has various species including R. caespitosus, R. delemar, R. homothallicus, R. microsporus, R. arrhizus (R. oryzae), R. reflexus, R. schipperae, and R. stolonifer that grow in soil, fruits, and other decaying food material. Some of the Rhizopus species are pathogenic and cause diseases lethal to plants and humans, whereas some have economic importance. Certain species can act as plant pathogens that affect crops, some are producers of enzymes in industrial bio-fermentation, and others are used as fermentation agents in food production.


The Kingdom Fungi has five true Phyla, Chytridiomycota (Chytrids), Zygomycota (conjugated fungi), Ascomycota (sac fungi), Basidiomycota (club fungi), and Glomeromycota. Rhizopus belongs to the Phylum Zygomycota.




Rhizopus spp. – Notice the characteristic vegetative features such as pigmented Rhizoids, Stolons, Sporangiophores, and Columella


Rhizopus spp. has a rapid growth rate and can mature in 4 days. The external appearance is cottony thread-like which is pale white in colour that turns to grey and yellowish brown in time. The colony can grow well under 15°C to 30°C in moist or damp environments. They require damaged host tissue to invade


Rhizopus has some characteristic vegetative properties for identification. The mycelia is composed of hyphae (filaments) and is attached to the substratum via a branched, root-like pigmented structure called Rhizoids. Their main use is to maintain a grip on the host and absorb water and minerals. Mycelium produces horizontally running hyphae called stolons that allow the fungus spread laterally. From stolons, vertically growing reproductive mycelia are formed called sporangiophores. Sporangiophores bear a globose/oval structure called sporangia, which produces asexual spores called sporangiospores. The hyphal cell wall is made up of chitin and chitosan. The cytoplasm is aseptate and multinucleated.

Life Cycle

Rhizopus spp.

Sexual Reproduction in Rhizopus spp.


Asexual Reproduction in Rhizopus spp. by Sporangiospores and Chlamydospores

Rhizopus spp. reproduces via vegetative, sexual, and asexual mode.

  • Vegetative reproduction: It takes place through fragmentation.
  • Sexual reproduction: It takes place by gametangial conjugation of two compatible hyphae.
  • Asexual reproduction: It takes place with the formation of sporangiospores and chlamydospores.


Rhizopus require minimal conditions to grow and hence are relatively easy to culture for industrial use. Some Rhizopus species serve great commercial purposes in bioindustries, medicines, food, textile, and leather manufacturing. Here are some of the Rhizopus species with their applications discussed as follows:

R. stolonifer

R. stolonifer

Rhizopus stolonifer, black bread mold

Rhizopus stolonifer is commonly known as the black bread mould.

Ecological role 

Rhizopus stolonifer plays an important role in the recycling of nutrients, sugar, and starch. It helps in the decomposition of organic matter and releases nutrients into the environment.

Bioindustrial Role 

Production of Organic Compounds

Rhizopus stolonifer is used in the commercial production of organic compounds such as ethanol, lactic acid, citric acid, fumaric acid, and cortisone at the industrial level. R.stolonifer is cultivated via a fermentation process and produces these organic compounds as byproducts. These byproducts are then extracted and purified for suitable industrial use.

  • Citric acid: It is used in various food and beverage products and has many industrial applications.
  • Fumaric acid: It is used in the treatment of autoimmune diseases, manufacturing polyester resins and polyhydric alcohols, as a food additive, and as a mordant for dyes.
  • Cortisone: It is used in the treatment of arthritis, inflammation, asthma, and other medical conditions.
  • Ethanol: It has major applications in alcoholic beverages, solvents, and petrol production.
  • Lactic acid: It is used in the food industry, pharmaceuticals, textile dyeing, plastic manufacturing, and leather tanning. It also has significant medical applications.
  • Enzymes: Rhizopus stolonifer can produce amylase and protease, which are used in food processing, textile manufacturing, and other industrial applications.
Production of fermented foods 

Rhizopus stolonifer is used in the production of fermented foods such as Tempehm miso, natto, and sake. These are traditional Asian cuisines and are produced by fermenting Rhizopus stolonifer with cereals such as rice and soybean.

Medicinal Use

Rhizopus stolonifer is used in the treatment of hormonal deficiencies. It can also produce steroids commonly present in birth control pills. It is used in the treatment of diseases like diabetes, Alzheimer, and cancer. Rhizopus stolonifer is capable to evoke allergic reactions and hence has an important use in allergenic testing.


Rhizopus stolonifer has degradative properties against pollutants and is used in soil and water purification.

R. arrhizus (R. oryzae)

Rhizopus arrhizus (R. oryzae)

Rhizopus arrhizus (R. oryzae)

Rhizopus arrhizus, also known as Rhizopus oryzae is similar to Rhizopus stolonifer in characteristics but is distinguished by smaller sporangia and aerially dispersed sporangiospores.


R. oryzae is used for the absorption of heavy metals in pollutant-affected water and soil. Soil polluted with uranium and thorium has been studied to have a lower contamination rate after treatment with Rhizopus arrhizus.

Industrial Uses

R. arrhizus can consume various compounds as Carbon and energy source which makes it a safe choice for bioindustrial application. It has greater application in the fermentation industry and is used in steroid transformations. Its culture media produces protease, cellulase, urease, ribonuclease, pectate lyase, polygalacturonase, amylase, and lipase enzymes that are significant components in biotechnology, food industry, and others. Cellulases produced in R.arrizus  has multiple applications in biotechnology, textiles, food, brewery, animal feed, laundry, and agriculture. When fermented with R. arrhizus under aerobic conditions, both glucose and xylose are converted into lactic acid and byproducts including glycerol, xylitol, ethanol, carbon dioxide, etc. Agricultural byproducts like sawdust, wheat straws, corn cobs, etc, are fermented with R. oryzae to form Endo-xylanase, a key enzyme for xylan depolymerisation. Pectinases found in the culture media of R. oryzae serve various purposes in the food and bioindustry, such as:

  • Extraction of flavour and oils from plants
  • Extraction and purification of fruit juices and wines
  • Fermentation of tea and coffee
  • Manufacture of hemp, jute and linen from cellulose fibres

R. oryzae can produce extracellular isoamylase to be used in sugar production industries for saccharifying potato starch, tapioca, oat, and tamarind kernel. Proteases that are found in R. oryzae, have increased application in food, pharmaceutical, detergent, leather, and tanning industries. Lipase found in R. oryzae has various biotechnology applications. Moreover, it is used in the commercial production of organic compounds including cortisone, esters, lactic acid, and alcoholic beverages like Parakari (extracted from cassava). It is a popular food component in Indonesia and Malaysia, used traditionally to ferment soybean to produce Tempeh, which is a traditional dish made by deep-frying fermented soybeans. It is also used to ferment glucose to form lactate, which has multiple uses in the food and plastic industries. Fruits, nuts, and grains treated with R. arrhizus change their original taste to acidic, sweet, or bitter.

R. microsporus 

Rhizopus microsporus

Rhizopus microsporus with sporangiospores

Rhizopus microsporus is a plant pathogen that infects rice, maize, and sunflower. However, it is used for commercial purposes due to its characteristic properties. It is used in the fermentation of soybean to form Tempeh and sufu. It has the bacterial endosymbiont Paraburkholderia rhizoxinica which is used to produce the antitumor drug rhizoxin.

Key Notes

  • Rhizopus are saprophytic fungi, belonging to the phylum Zygomycota.
  • They are fast-growing, white, pale, and greyish-brown in colour and have a cotton-like appearance.
  • It is mainly found in moist places and on decaying organic matter such as bread, fruits, living plants, and inorganic matter like animal excreta. It is parasitic on animals.
  • Rhizopus spp. are coenocytic fungi with branched hyphae called mycelia that form the aerial stolons, sporangiophores, sporangia, and sporangiospores and are attached to substratum via root-like structures called rhizoids.
  • They reproduce via vegetative, sexual, and asexual reproduction.
  • There are various species of Rhizopus including Rhizopus stolonifer, Rhizopus arrhizus, Rhizopus microsporus, R. caespitosus, R. delemar, R. homothallicusR. reflexus, R. schipperae, etc. 
  • Some species of Rhizopus have economic, ecological, and industrial uses, and some have pathogenic properties.
  • Different species of Rhizopus are used in food and beverages fermentation industries, in the production of organic compounds (such as ethanol, citric acid, lactic acid, cortisone and fumaric acid), in bio-industrial manufacturing of enzymes (such as protease, amylases, cellulase, pectinases, and phytases), and textile, agriculture and feed industries.

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