Comparative inducibility of bacteriophage in naturally lysogenic and lysogenized strains of Listeria spp. by u.v. light and Mitomycin C

A total of 34 listeria lysogens, which are either natural phage carriers or artificially lysogenized strains, were tested for production of prophage upon treatment with u.v. light and Mitomycin C (MC). Most strains were readily inducible, in particular the generated prophage carriers tested. The yield of free phage could be increased up to 1600-fold. With respect to the listeria lysogens investigated, MC was found to be a more powerful inducing agent than u.v. light. Thus, it should be further applied in screening for new phages.