Characterization of the Genome of the Streptococcus lactis "subsp. diacetylactis" Bacteriophage P008 Wide-spread in German Cheese Factories.

The isodiametric bacteriophage P008 is wide-spread in German cheese factories. P008 was propagated in Streptococcus lactis "subsp. diacetylactis F7/2. As an ultrastructural peculiarity whiskers originating from its collar were detected. In M17-broth, the latent period lasted about 30 min at 30°C. The burst size was about 10. The double stranded DNA of phage P008 has a GC-content of 37.5 mol % as determined by its melting point and by high performance liquid chromatography of acid hydrolysates. Electron microscopy revealed a molecular weight of the DNA of 19.6 Mdal which was confirmed by agarose gel electrophoresis of restriction endonuclease fragments. DNA purified by phenol extraction and prepared for electron microscopy by the aqueous spreading technique consisted predominantly of open circular molecules. Treatment of the DNA with nuclease S1 or application of the formamide spreading technique converted all the circular into linear molecules. This suggests the presence of cohesive ends in P008 DNA. In order to be suitable as a reference DNA molecule, a restriction endonuclease map of P008 DNA was constructed. The enzymes BamH I, Bgl I, Pst I, Sal I and Sma I were not able to cleave P008 DNA. One cut was produced by Bel I, Bgl II and Hind III, two cuts occurred with Cla I, four cuts with Eco RI, five or six cuts with Pvu II, six cuts with Hae III and numerous cuts with Hha I, Hinc II and Hpa II. Copyright © 1983 Gustav Fischer Verlag, Stuttgart/New York. Published by Elsevier GmbH.. All rights reserved.