Rhizopus arrhizus

Rhizopus arrhizus is a common species of fungus in the family Rhizopodaceae. It is known for its role in food spoilage, particularly of bread and other baked goods, and for its potential to cause human disease.

Taxonomy

The species was first described in 1820 by the German mycologist Christiaan Hendrik Persoon. The genus name Rhizopus comes from the Greek words for "root" and "foot", referring to the root-like structures that the fungus forms. The species name arrhizus means "without roots", a reference to the fact that this species does not form the root-like structures typical of other members of the genus.

Description and Identification

Rhizopus arrhizus is a fast-growing, filamentous fungus. It forms a mycelium of white, cottony hyphae, and produces black, round spores. The spores are produced in a sporangium, a specialized structure at the end of a stalk called a sporangiophore. The sporangia are typically spherical and filled with numerous spores.

Ecology and Distribution

Rhizopus arrhizus is a cosmopolitan species, found worldwide. It is a saprophyte, meaning it obtains its nutrients from dead or decaying organic matter. It is commonly found in soil, on decaying plant material, and in stored food products.

Role in Food Spoilage

Rhizopus arrhizus is a common cause of food spoilage. It is particularly associated with the spoilage of bread and other baked goods, where it causes a condition known as bread mold. The fungus can grow rapidly on bread, producing a characteristic fuzzy, white mycelium and black spores.

Human Disease

In humans, Rhizopus arrhizus can cause a disease known as mucormycosis, a serious and often fatal fungal infection. This typically occurs in individuals with weakened immune systems, such as those with HIV/AIDS, diabetes, or those receiving immunosuppressive therapy.

See Also

• Rhizopus
• Mucormycosis
• Bread mold
• Fungal diseases