Host-range and partial characterization of several new bacteriophages for Bacillus megaterium QM b1551.

Several phages infecting Bacillus megaterium QM B1551 have been isolated from the soil and partially characterized. These phages, designated MP9 to MP50, were tested for host-range on several strains of B. megaterium and 13 other Bacillus species. All the phages only infected B. megaterium and on the basis of host-range patterns, 23 groups could be distinguished. The phage patterns also distinguished subgroups of B. megaterium strains within the species and should be useful in phage typing. The phages have varying sensitivities to heat, salts and organic solvents and are all double-stranded DNA phages. Thirty-two have been examined by electron microscopy and are Bradley types A, B and C. This is the first large collection of B. megaterium phages that has been characterized.