Toxin production by Corynebacterium diphtheria is due to ?
Chromosomal mutation
Presence of plasmid
Lysogenic conversion
Transformation
Ans. is 'c' i.e., Lysogenic conversion o The toxigenicity of the diphtheria bacilli depends on the presence in it of corynephages (tox +). Nontoxigenic strains may be rendered toxigenic by infecting them with beta phage or some other larger phage. This is known as lysogenic conversion or phage conversion.
Corynebacterium