3 6, Alcaligenes 



The genus Alcaligenes is composed of peritrichously flagellated 

 bacteria and related nonflagellated types which do not attack 

 carbohydrates. Many types of polar flagellated bacteria have 

 cultural and physiological characteristics very similar to Alcali- 

 genes species. These polar flagellated bacteria are often mistaken 

 for Alcalipenes and are found in culture collections as Alcaligenes 

 species of one kind or another. It is impossible to identify an or- 

 ganism as Alcaligenes without determining the nature of the flagel- 

 lation. Although Alcaligenes species are ubiquitous in nature thev 

 are not as common as most bacteriologists believe. The author has 

 studied a fair number of strains of Alcaligenes obtained from a 

 variety of sources over a period of several years. Most of the 

 species Hsted in Bergey's Manual are unidentifiable and should be 

 discarded. The author includes Alcaligenes (Brucella, Bordetella) 

 bronchisepticus in the genus because of its similar morphological 

 and physiological characteristics. 



Flagellar Characteristics 



In some strains the flagella are quite numerous and well-formed 

 but in most strains the flagellation is only fair or poor (Table VII). 

 The most common flagellar shape is the normal and the only 

 definite other shape found was the curly. All strains of Alcaligenes 

 bronchisepticus studied, twenty in number, had normal flagella 

 only, and so did the two strains studied of Alcaligenes denitrificans. 

 One strain of Alcaligenes faecalis had only curly flagella and one 

 strain had some individuals with normal flagella and some with 

 curly flagella but not both types of flagella on the same individual. 

 A peritrichously flagellated mutant of Lophomonas faecalis had 

 only curly flagella (Fig. 38). 



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