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THE ACTINOMYCETES, Vol. I 



Table 14 

 Distribution of different spore types among the various groups of streptomyces (Kutzner) 



that, in the process of sporulatioii, an empty 

 spore may appear in a chain of normal 

 spores. This was ascribed to lysis. They also 

 observed giant spores, which were ascribed 

 to anomalies in the septation process. 



Kutzner (1956) tabulated a large number 

 of strains of Streptomyces for their spore 

 structure, as shown in Table 14. Of the 175 

 subgroups examined, 133 produced smooth 

 spores, 24 spiny, 12 hairy, and 6 warty 

 spores. 



Spores are produced even more readily in 

 streptomyces cultures grown in a submerged 

 state than on the surface of solid or liquid 

 media. The rapidity and extent of sporula- 

 tion depend entirely upon the strain of the 

 organism. Both kinds of spores are similar 

 in their morphological and physiological 

 properties (Carvajal). 



Spores of actinomycetes produced in the 

 aerial mycelium are resistant to desiccation 

 (Berestneff, von Plotho, Stapp). They are 

 highly hydrophylic, with the result that 

 inoculation of stationary liquid media with 

 spores of an organism gives an early surface 

 growth. Erikson (1947) ascribed this to the 

 presence of lipoid substances in their outer 

 wall. 



Under iaA'oral)le conditions of moisture 



and temperature, the spores of actinomy- 

 cetes germinate rapidly. They give rise to 

 one to four germ tubes. The different types 

 of spores vary greatly in this respect. The 

 germ tubes may appear at one end or at 

 both ends of the spore. Lieske differentiated 

 between the processes of germination of the 

 spherical and cylindrical spores. Baldacci et 

 al. (1956) described several types of germi- 

 nation: single and double unipolar, as well 

 as single and triple bipolar. 



Other Reproductive Methods 



Reproduction among actinomycetes may 

 also occur by the vegetative process, or 

 through the growth of pieces of mycelium, 

 by the formation of buds which graduall}' 

 grow into branched hyphal threads, as well 

 as by means of the chlamydospores. 



Constancy of Morphological Properties 

 Among Actinomycetes 



Although one may observe a certain 

 amount of overlapping among the species of 

 Actinomijces and Nocardia, and between 

 Nocardia and Streptomyces, the morphologi- 

 cal, clKMiiical, and cultural properties char- 

 acteristic of each genus justify confidence 

 in their natural status. 



