Chapter 10 



The Genus Waksmania {Microbispora) 



The genus Waksmania (Microbispora) is 

 characterized by the paired spores produced 

 on aerial hyphae (Fig. 56). 



The fine mycelium (about 1 n in diameter) 

 is differentiated into (a) primary or substrate 

 mycelium which grows into, and forms a 

 compact layer on top of agar media, and (b) 

 secondary or aerial mycelium which arises 

 from the primary mycelium but grows into 

 the air, away from the agar surface. The 

 substrate mycelium does not bear spores of 

 any type; the aerial mycelium bears spores 

 which are formed in longitudinal pairs. The 

 spores are produced either directly on the 

 aerial hyphae or on sporophores which 

 branch from the aerial hyphae. 



The sporophores may be so short that the 

 spores appear to be produced directly on the 

 mycelium. The aerial mycelium forms a bud 

 at the side, and later the bud, or occasionally 

 the tip of the side branch, swells and is 

 separated by a cross wall giving rise to two 

 spherical or oval conidia, 1.4 to 1.6 m in 

 diameter (Fig. 57). 



The germination of the spores and the 

 structure of substrate mycelium are similar 

 to those of Streptomyces. 



The type species is Waksmania rosea 

 Lechevalier and Lechevalier. 



Waksmania rosea Lechevalier and Leche- 

 valier, 1957 (Lechevalier, M. P. and Leche- 

 valier, II. J. Gen. Microbiol. 17: 104-111, 

 L957). 



Synonym: Microbispora rosea Xonomura 

 and Ohara, 1957 (Nonomura, H. and Ohara, 

 V., .1. Ferm. Technol., 35: 307 -311, 1057). 



Morphology: The dominant form of this 



organism on some media, after 14 days at 

 30°C, may consist of chlamydospores. 

 Hyphae do not segment, even in old cultures. 

 "Fairy rings," or alternating areas of aerial 

 mycelium with zones which have none, occur 

 on some media. "Coremia-like" aggregations 

 of aerial hyphae are formed on a variety of 

 substrates. Small branches are produced 

 monopodially in respect to the main axis of 

 the aerial sporogenous hyphae. Spores are 

 borne at the tip of these branches or sporo- 

 phores. Spores are spherical, 1.5 to 2.0 m, 

 usually about 1.7 to 1.8 m- Spores are borne 

 terminally on sporophores, as well as at the 

 tips of the main sporogenous hyphae and 

 branches. They are also borne directly on 

 the sporogenous hyphae. Spores are formed 

 in pairs and, when mature, are very easily 

 detached from the sporophore and from each 

 other. 



Agar media: Growth slow on nutrient 

 agar. Color of substrate growth pale pink to 

 coral-orange, changing to chest nut -brown. 

 Diffusible pigment very slight. Aerial myce- 

 lium white, powdery, with tendency to form 

 fairy rings on some media. 



Sucrose nitrate agar: Growth thin, yel- 

 lowish-white. Aerial mycelium scant. Some 

 malformed spores appear. 



(ilucose-asparagine agar: Growth meager, 

 colorless. No aerial mycelium. 



Yeast-glucose agar: Growth white-tan, 

 glistening, becoming dark brown and con- 

 voluted. Xo aerial mycelium. 



Oatmeal agar: Orange-pink vegetative 

 growth. Aerial mycelium white, with light 

 pink spores. Earthy odor. 



2! IS 



