Rhizopus oligosporus | |
---|---|
Rhizopus oligosporus on homemade tempeh | |
Scientific classification | |
Kingdom: | Fungi |
Order: | Mucorales |
Family: | Mucoraceae |
Genus: | Rhizopus |
Species: | R. oligosporus |
Binomial name | |
Rhizopus oligosporus Saito |
Rhizopus oligosporus is a fungus of the family Mucoraceae and is a widely used starter culture for the production of tempeh at home and industrially. As the mold grows it produces fluffy, white mycelia, binding the beans together to create an edible "cake" of partly catabolized soybeans. The domestication of the microbe is thought to have occurred in Indonesia several centuries ago.
R. oligosporus is the preferred starter culture for tempeh production for several reasons. It grows effectively at high temperatures (30-40 °C) which are typical of the Indonesian islands, it exhibits strong lipolytic and proteolytic activity that create desirable properties in tempeh and it produces metabolites that allows it to inhibit and thus outcompete other molds and gram-positive bacteria, including the potentially harmful Aspergillus flavus and Staphylococcus aureus.
R. oligosporus is at present considered to be a domesticated form of Rhizopus microsporus and its proper taxonomic position is thus Rhizopus microsporus var. oligosporus. R. microsporus produces several potentially toxic metabolites, rhizoxin and rhizonins A and B, but it appears the domestication and mutation of the R. oligosporus genome has led to the loss of genetic material responsible for toxin production.