Flagellar characteristics ofRhizobium species

Summary

The flagellation and growth characteristics of 82 strains ofRhizobium were studied. The strains were originally isolated from the root nodules of 19 genera and 35 species of leguminous plants.

Two morphological types of bacteria were found which differed mainly in the nature of their flagellation. The one type shows a most unusual and unique flagellation with single subpolar flagella of wavelength averaging from 1.9 to 2.2 microns. The other type shows peritrichous flagellation with usually one and, less often, several flagella per flagellated individual. The flagellar wavelength of the latter type averaged from 1.3 to 1.6 microns. Most strains of both types were rather poorly flagellated. An almost perfect correlation was found between the type of flagellation and the growth rate in peptone-mannitol medium. The subpolar types grew relatively slowly and the peritrichous types relatively rapidly.

Some strains of the subpolar type showed flagellar variants with multiple flagella of very short wavelength in addition to the normal subpolar flagellum. A few individuals showed the short wavelength flagella only.