Isolation and partial characterization of three rumen Lactobacillus plantarum bacteriophages

The first isolation of Lactobacillus plantarum bacteriophages from ruminal fluid is reported. Three bacteriophages were characterized on the basis of plaque morphology, host ranges, stability, electron microscopic morphology and DNA restriction endonuclease digestion patterns. They formed clear plaques and are placed in group A of Bradley's scheme and have identical host ranges. Bacteriophages were stable to urea and chloroform. They were relatively thermostable but partially inactivated by rumen fluid and by acetate. DNA restriction analysis showed that phage L20 had different numbers of cleavage sites in comparison with the next two phages.