Preliminary characterization of an ineffective Frankia derived from a spontaneously neomycin-resistant strain

Five strains of Frankia isolated from actinorhizae of 3 alder species were cultivated with various concentrations of neomycin in the medium. For one strain, resistance to neomycin was associated with lost of effectiveness. The ineffective strain was as infective as the parent strain. Protein and isoenzymes patterns showed that the ineffective and the parent strains were quite similar. The ineffective strain differentiated vesicles inside the infected host-cells.