24. Spirillum 



A representative collection of twenty-six cultures of Spirillum 

 were studied morphologically. One culture of SpiriUum vir- 

 ginianum was received from C. B. van Niel, Hopkins Marine 

 Station; one culture of SpiriUum serpens came from the Midwest 

 Culture Service; and all the others from Marion Williams, Uni- 

 versity of Southern IlHnois. The Williams collection of twenty- 

 four cultures was about evenly divided into fresh water and 

 marine forms. The marine forms were cultured in media with 



Fig. 26. a. Spirillum serpens, Williams. A typical large fresh water spiril- 

 lum with a tuft of flagella at both ends. Note the relatively short flagella with 

 few curves. Organisms with flagella only at one pole do occur but not as 

 commonly as the amphitrichous types. 



b. Spirillum sp., Williams LA-1. A fresh water spirillum with a large 

 number of flagella. The tufts of lateral flagella presumably originate at points 

 of somatic cleavage. 



c. Spirillum sp., Williams Sb-10. A typical, medium sized fresh water 

 spirillum. 



d. S. itersonii, Giesberger strain. A relatively small fresh water spirilkmi. 



e. f. S.virginianum, Hopkins Marine Station 0.1.1. This spirillum tends 

 to be short and only slightly curved. Some individuals may even be perfectly 

 straight like that pictured in e. The flagellation is polar lophotrichous and 

 typical of spirilla. 



g. Spirillum sp., Williams Sb-9. A typical fresh water spirillum. 



h, i, j. Spirillum sp., Williams 2E-6. This is a typical marine spirillum. In 

 h is shown the normal or vegetative form, and in i and j, the "microcyst" form. 

 The microcysts are usually slightly oval and may have flagella at one or both 

 poles. The flagella apparently are not disturbed when the vegetative form 

 rounds up or condenses to form the microcyst. 



k. Spirillum sp. This organism was not isolated in culture but stained 

 directly from the intestinal contents of a dog. The soma is short and twisted 

 into a spiral. The flagellation is polar monotrichous. 



1. S. pohjmorphum, Williams. This species was the only one of the twenty- 

 six cultures studied with polar monotrichous flagellation. The culture grew 

 poorly and very slowly on the media used. The organism is rather small and 

 only a few individuals were flagellated. All flagellated indi\iduals had the 

 same type of polar monotrichous flagella. 



m. S. linum, Williams. This is a typical marine spirillum of average size. 

 The organism to the right shows a flagellum with several curves and relatively 

 short wavelength, along with the more normal flagella of spirilla. This type 

 of flagellum appears to be extremely rare in spirilla and was seen only in this 

 particidar culture. It may be considered as equivalent to the curly type of 

 flagella in other bacteria. 



e,f. From T. P. Galarncault, and E. Leifson, Can. J. Microbiol. 2, 102-110 

 (1956). k. From E. Leifson, }. Bactcriol. 62, 377-389 (1951). 



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