Identification of PK 1 bacteriophage DNA in Streptococcus mutans

A lysogenic bacteriophage PK 1 and plasmid DNA's in Streptococcus mutans PK 1 have been characterized by electron microscopy PK 1 phage DNA molecules were observed in both linear and circular forms, which gave the molecular weights of (28.9 +/- 0.4) x 10(6) and (27.4 +/- 0.2) X 10(6) daltons, respectively. Plasmid DNA has a molecular weight of 4.0 X 10(6) daltons. No difference of density in CsCl density gradient between linear and circular forms of phage DNA and plasmid DNA was observed.