Rhizopus oligosporus
Encyclopedia
Rhizopus oligosporus is a fungus of the family Mucoraceae that is a widely used starter culture for the home production of tempeh
. The spores produce fluffy, white mycelia
, binding the beans together to create an edible “cake” of partly fermented soybeans.
Rhizopus oligosporus produces an antibiotic that inhibits gram-positive
bacteria, including the potentially harmful Staphylococcus aureus
and the beneficial Bacillus subtilis
(present in nattō
), even after the Rhizopus is consumed. This supports anecdotal evidence that those who eat tempeh regularly have fewer intestinal infections.
One strain of this fungus used in tempeh
production was shown to contain bacterial endosymbionts of the genus Burkholderia
, which were shown to produce toxic rhizoxins
. Whether other strains used for tempeh production contain these bacteria has not been established.
Rhizopus oligosporus is more properly known as Rhizopus microsporus var. oligosporus.
Tempeh
Tempeh , or tempe , is a traditional soy product originally from Indonesia. It is made by a natural culturing and controlled fermentation process that binds soybeans into a cake form, similar to a very firm vegetarian burger patty...
. The spores produce fluffy, white mycelia
Mycelium
thumb|right|Fungal myceliaMycelium is the vegetative part of a fungus, consisting of a mass of branching, thread-like hyphae. The mass of hyphae is sometimes called shiro, especially within the fairy ring fungi. Fungal colonies composed of mycelia are found in soil and on or within many other...
, binding the beans together to create an edible “cake” of partly fermented soybeans.
Rhizopus oligosporus produces an antibiotic that inhibits gram-positive
Gram-positive
Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink...
bacteria, including the potentially harmful Staphylococcus aureus
Staphylococcus aureus
Staphylococcus aureus is a facultative anaerobic Gram-positive coccal bacterium. It is frequently found as part of the normal skin flora on the skin and nasal passages. It is estimated that 20% of the human population are long-term carriers of S. aureus. S. aureus is the most common species of...
and the beneficial Bacillus subtilis
Bacillus subtilis
Bacillus subtilis, known also as the hay bacillus or grass bacillus, is a Gram-positive, catalase-positive bacterium commonly found in soil. A member of the genus Bacillus, B. subtilis is rod-shaped, and has the ability to form a tough, protective endospore, allowing the organism to tolerate...
(present in nattō
Natto
is a traditional Japanese food made from soybeans fermented with Bacillus subtilis. It is popular especially as a breakfast food. As a rich source of protein and probiotics, nattō and the soybean paste miso formed a vital source of nutrition in feudal Japan. Nattō can be an acquired taste because...
), even after the Rhizopus is consumed. This supports anecdotal evidence that those who eat tempeh regularly have fewer intestinal infections.
One strain of this fungus used in tempeh
Tempeh
Tempeh , or tempe , is a traditional soy product originally from Indonesia. It is made by a natural culturing and controlled fermentation process that binds soybeans into a cake form, similar to a very firm vegetarian burger patty...
production was shown to contain bacterial endosymbionts of the genus Burkholderia
Burkholderia
Burkholderia is a genus of proteobacteria probably best known for its pathogenic members:Burkholderia mallei, responsible for glanders, a disease that occurs mostly in horses and related animals;...
, which were shown to produce toxic rhizoxins
Rhizoxin
Rhizoxin is an antimitotic agent with anti-tumor activity. It is isolated from a pathogenic plant fungus which causes rice seedling blight.-Biosynthesis:...
. Whether other strains used for tempeh production contain these bacteria has not been established.
Rhizopus oligosporus is more properly known as Rhizopus microsporus var. oligosporus.