CHARACTERIZATION OF A PROLATE-HEADED BACTERIOPHAGE OF LACTOBACILLUS-DELBRUECKII SUBSP LACTIS, AND ITS DNA HOMOLOGY WITH ISOMETRIC-HEADED PHAGES

A new Lactobacillus delbrueckii subsp. lactis bacteriophage, JCL 1032, was characterized. JCL 1032 had a small, elongated prolate head, and a long non-contractile tail with cross-bars. The restriction map of JC L 1032 genome was constructed with five endonucleases. The genome was 45.8 kb in size, and it had cohesive ends (cos). Molecular masses of t he phage structural proteins were also determined. JCL 1032 showed DNA homology with morphologically dissimilar, isometric-headed phages of Lb. delbrueckii (subsp. lactis and subsp. bulgaricus) when analyzed by Southern hybridization. Although in general JCL 1032 was only distant ly related to isometric-headed phages, there were also a few short hig hly homologous (minimal homology 84%) DNA regions.