A simple method for the isolation of flagellar shape mutants in Salmonella

During prolonged static cultivation of liquid cultures of Salmonella strains with normal flagella, flagellar shape mutants occurred spontaneously and their proportion in the cultures increased so that they were easily isolated by spreading dilutions of the cultures on semisolid medium. By this method various types of flagellar shape mutants, including curly, straight and polymorphous mutants, were obtained.