Characterization of temperate bacteriophages of Bacillus thuringiensis.

Eight phages lysogenic for Bacillus thuringiensis var. galleriae which elicit the lytic response in B. thuringiensis var. subtoxicus were isolated by induction of the host strains. We have divided these phages into three groups: group I, phages GT-t to GT-5; group II, GT-6 and GT-7; group IlI, GT-8. The following properties of the phages were examined: morphology, host range, serum neutralization, adsorption rates, one-step growth characteristics and thermal inactivation rates. The three groups are readily distinguishable on the basis of morphology and host range. Group II and III show a high degree of homology in regard to their host range, serum neutralization, one-step growth and thermal inactivation characteristics. The phages bear a certain resemblance to previously reported virulent phages of B. thuringiensis (Chapman & Norris, 1966; Colasito & Rogoff, 1969).