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THE ACTINOMYCETES, Vol. II 



2. Sporophores form extensive branching. 



a. Growth colorless; brown spores 

 appear in mass. 



7. Micromonospora globosa 



b. Growth pigmented. 



a 1 . Growth green to dark green. 

 a 2 . Spores blue. 



3. Micromonospora coerulea 

 b 2 . Spores black or brown. 



1. Micromonospora bicolor 

 b 1 . Growth pink to orange-colored. 

 a 2 . Pigment not excreted into 

 substrate. 



8. Micromonospora parva 



I) 2 . Red-brown pigment excreted 

 into substrate. 

 5. Micromonospora fusca 

 II. Sporophores short. 



1. Growth brown; spores dark brown. 



4. Micromonospora elongata 

 B. Anaerobic. 



9. Micromonospora pro- 

 pionics 



Various other micromonosporas have been 

 observed in natural substrates, but either 

 have not been isolated or only insufficiently 



f 



***»••» *> 



% 



to 



Figure 52. Micromonospora (clumps of spores) 

 growing in a compost. 



;« 



Figure 53. Micromonospora (double spores) 

 growing in a compost. 



studied. This is true, for example, of the 

 cellulose-decomposing, facultative anaerobic 

 form studied by Meyer, 1934 (Prevot, 1955); 

 and of M. cabaelli Maquer and Comby 

 (Prevot, 1955). It is also true of some of the 

 forms reported by Waksman et al. (1939). 

 Some of the micromonosporas (M. mono- 

 spora and M. vulgaris) have been placed, 

 because of their temperature optima, among 

 the thermophilic forms. 



Description of Micromonospora Species 



1. Micromonospora bicolor Krassilnikov, 

 1941 (Krassilnikov, N. A. Actinomycetales. 

 [zvest. Akad. Nauk. SSSR, 1941, p. 131). 



Morphology: Sporophores long, branch- 

 ing, 10 to 25 /x; spores oval, 1.0 to 1.2 by 

 0.8 p. 



Synthetic agar: Growth green, smooth; 

 covered with a dark brown to black hue of 

 spore-bearing hyphae. Pigment insoluble. 



Nutrient agar: No growth. 



Potato: No growth. 



Gelatin: Xo growth. No liquefaction. 



Milk: Unchanged. 



Starch: Not liquefied. 



