Abstract
Bacteriophages Clmll, ClmX and ClmXC for Clavibacter (Cl.) michiganense subsp. nebraskense were characterized with respect to biological and physical properties. All phages produced clear plaques on strain CN18-5, the original propagating host. On strain CN76-2, ClmX produced predominantly turbid plaques with a few clear plaques, from which ClmXC was derived. The host range of the three phages was restricted to strains of Cl. michiganense subsp. nebraskense. Adsorption rate constants and burst sizes of the three phages were in the range of 2.9 to 9.4×10-9ml/min and 6 to 19 virions/cell, respectively. All phages were morphologically similar with a hexagonal head about 60nm in width and a flexuous tail approximately 235nm long. The type of nucleic acid was double-stranded DNA. Agarose gel elctrophoresis of restriction endonuclease digests of the phage DNAs indicated that the three phages are similar, but distinguishable in DNA structure. C1mXC was probably a deletion mutant of ClmX.
