14, Lophofttonas 



In the genus Lophomonas are classified a group of ubiquitous 

 bacteria found in soil, water, and occasionally isolated from human 

 and animal material such as feces, blood, etc. They are charac- 

 terized by their distinctive flagellation and failure to metabolize 

 carbohydrates. Thirty-seven strains have been studied in the au- 

 thor's laboratory. All were sufficiently alike to be placed in a 

 single species, Lophomonas faecalis (Fig. 16). 



Flagellar Characteristics 



All strains of Lophomonas by definition are polar multitrichous 

 or lophotrichous. The flagella tend to be relatively short with very 

 long wavelength such that it is rare to find a flagellum with a 

 complete wave. This type of flagellation is also typical of spirilla 

 but rare in other bacteria. 



Several years ago a culture was received from the American 

 Type Culture Collection labeled Vibrio percohns, 8461. When this 

 culture was stained both polar and peritrichous individuals were 

 observed on the slides. Some individuals showed both polar and 

 lateral flagella of different wavelength. By plating, the original 

 culture could be separated into pure variants with polar and 

 peritrichous flagella, respectively. The mixed type could not be 

 isolated and is an unstable transitional type. The two flagellar 

 variants were physiologically identical but differed slightly in 

 flagellar antigenicity. The polar variant continued to produce 

 peritrichous forms but the peritrichous variant appears to be stable. 

 In other words, the mutation is always from the polar type to the 

 peritrichous type and never the reverse. This type of mutation 

 appears to be the first of its kind ever described and substantiated 

 by photomicrographs of the mutants and their intermediates. The 

 mutation raises a serious problem in bacterial taxonomy and sug- 

 gests that a closer relationship exists between polar and nonpolar 

 flagellates than our present taxonomy indicates. The peritrichous 

 mutant is a typical Alcaligenes sp. with curly flagella. None of the 

 other thirty-six strains of Lophomonas studied have shown any 

 evidence of a similar, or any, morphological mutation. 



The wavelength of the polar flagella is somewhat indefinite 

 since a complete wave is rarely found and only half waves can 

 be measured. The wavelengths and amplitudes of the polar flagella 

 of the various strains studied did not show significant differences. 

 The mean wavelength of the polar flagella for the species was 



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