Rhizopus microsporus var. oligosporus

Rhizopus microsporus var. oligosporus is a rare cause of human zygomycosis (Tintelnot and Nitsche 1989). Colonies are pale yellowish-brown to grey and sporulation is often poor. Rhizoids are subhyaline and simple. Sporangiophores are brownish, up to 300 µm high and 15 µm wide, with 1-3 produced together. Sporangia are black, spherical, up to 100 µm in diameter. Columellae are subglobose to somewhat conical.   Sporangiospores are subglobose to globose, up to 9 µm in diameter, almost smooth, with larger spores often irregular in shape. Chlamydospores are abundant, hyaline, single or in chains, spherical, ellipsoidal or cylindrical, 7-35 µm in diameter. Zygospores are not known. There is growth at 45C with a maximum of 46–48OC.   RG-2 organism.

Mycosis: Zygomycosis

Further reading:

Domsch, K.H., W. Gams, and T.H. Anderson. 1980. Compendium of soil fungi. Volume 1. Academic Press, London, UK.

Ellis, D.H. 1997. Zygomycetes. Chapter 16 In Topley and Wilson's Microbiology and Microbial Infections. 9th edition Edward Arnold London pp247-277.