- Rhizopus microsporus
- Rhizopus oryzae
- Rhizopus stolonifer
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.
|Surface:||Texture deeply cottony; White becoming gray-brown on surface.|
|Growth Rate:||Very rapid growth.|
Rhizopus is recognized by the presence of well developed rhizoids situated at the point where sporangiophores are attached to the stolons. In contrast to Mucor , Rhizomucor and Absidia , the sporangiophores are often unbranched and grouped in tufts.
|Organism||Pathogenic||Maximum Growth Temperature||
|Equal size, average length 4-6um; smooth to slightly striated; almost round to slightly elongated|
|Postive||40-46°C||150-300||500-3500||50-250||Almost round||Variable size, average length 6-8um; striated; elongated to lemon-shaped|
|Negative||30-32°C||300-350||1500-4000||150-350||Almost round||Variable in size, average length 9-11um; very striated; elongated to polyhedric|
Pathogenic strains grow better at 35 degrees C. than saprophytes.
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.
- Corn Meal Agar
- Malt Extract Agar
- Potato Dextrose Agar
- Sabouraud Dextrose Agar
- Wort Agar
|Temperature:||25 degrees C.|
1. Hensyl, William R. et al. 1990. Stedman's Medical Dictionary , 25th ed. Williams & Wilkins, Baltimore, MD.
2. St. Germain, Guy and Summerbell, Richard, Ph.D. 1996. Identifying Filamentous Fungi , 1st ed. Star Publishing Company, Belmont, CA.
3. Larone, Davise, H. 1995. Medically Important Fungi , A Guide to Identification . 3rd ed. American Society for Microbiology Press, Washington, D.C.
4. The Oxoid Vade-Mecum of Microbiology . 1993. Unipath Ltd., Basingstoke, UK.