Characterization of the bacteriophage B2 of Lactobacillus plantarum ATCC 8014

Bacteriophage B2 of Lactobacillus plantarum ATCC 8014, isolated in 1971, belonged to Bradley's group B. Electron microscopy revealed an isometric head (110 nm) and a long non-contractile and flexible tail (500 nm) containing about 75 regularly aligned lateral striations. Burst size was 12-14 phages per infectious centre. The latent period for phage development was 75 min and the rise period approximately 90 min. The phage particle contained 5 major proteins. The buoyant density of the phage in CsCl was measured as 1.575 g/cm3. B2 genome was a linear double-stranded DNA molecule of 37 +/- 1% guanosine-cytosine. Its size was 73 kilobase pairs (kbp). Restriction analysis of the genome showed that 4 restriction enzymes (Xba I, Sac I, Bgl II and Sma I) gave single site cuts in the DNA, while Ava I and Sal I formed 2 and 5 cuts, respectively.