Isolation of Motile Variants from Gas-vacuolate Strains of Ancylobacter aquaticus

Summary: Flagellate variants were selected from most of the nonmotile, gas-vacuolate strains of Ancylobacter aquaticus under study. The number and location of flagella on the cells were variable. Flagellins produced by five independently isolated strains of A. aquaticus were serologically related. Variants of strain M1 selected for their motility did not produce gas vesicles; however, gas-vacuolate, nonmotile clones arose in these motile variants at a frequency of about 10−2. Formation of flagella has also been found in ‘Renobacter vacuolatum’ and another heterotrophic gas-vacuolate bacterium that has not yet been identified.