Temperate bacteriophages and polyheads produced in the L form of Staphylococcus aureus after mitomycin induction.

A lysogenic strain of Staphylococcus aureus was transformed into its protoplast L form. After stabilization and subcultivation in the L-form state for more than 200 subcultivations, it was tested for maintenance and inducibility of the temperent phage found in the parent strain. In the parent strain and L form, optimal phage production was inducible by 1 and 2 micrograms of mitomycin-C/ml. Besides regular phages with heads of approximately 35 X 85 nm, some L-form cells also produced polyheads of up to more than 1000 nm in length.